But I'll be back tomorrow with my full response to this ridiculous infringement of personal privacy! If they inspected my kid's lunchboxes I'm figuring Child Protective Safety would be called. Oh, that's right, my 11 year old daughter and 7 year old son know more about the correct way to eat than these ignorant bureaucratic buffoons who actually still think that eating fat & cholesterol is bad for us.
Click here for the story!
Oh yeah, don't forget to check out the carb-laden School Luncheon Menu. It's getting worse everyone, not better....
dr jim
http://www.drjamescarlson.com/
Monday, February 20, 2012
Sunday, February 19, 2012
Can Eating Too Much Fat & Protein Actually Lead To Increased Fat Storage? Or, has Dr. Jim finally contradicted himself?
Dr. Carlson,
Thanks so much for your very detailed response to my question. It is incredibly helpful, and I'm sharing it with pretty much everyone I know. One very brief follow-up question though, if you wouldn't mind indulging me:
Excess carbs obviously lead directly to storage. But is it not possible for the body to convert and store fat and/or protein as well? In other words, a normal/reasonable amount of fat, protein, and cholesterol won't lead to fat conversion and storage when that same amount of carbs would. However, is this still the case if one consumes a serious excess of fat protein and cholesterol? (as might happen, say, when I spend a few hours at my favorite Brazilian steakhouse, Fogo de Chao).
Much thanks once again!
Sean
Hi Sean,
No problem and I like your follow-up questions too; I'm going to think this through as I type and explain kinda like an impromptu lecture, so enjoy! :-)
It is possible for the body to store excess fat and protein consumption as fat. Here's how; we'll look at fats first;
When we consume fats we consume them usually in the form of triglycerides. A triglyceride is composed of 3 (three) fatty acid side chains (hence the tri) attached to a glycerol backbone. While beta-oxidation of the acyl side chains will release acetyl groups that will shuttle into the Kreb's, this will also release the glycerol backbone. The glycerol backbone can indeed be transformed to glucose via gluconeogenesis.
It needs to be re-emphasized that gluconeogenesis is not the reversal of glycolysis; that gluconeogenesis occurs mainly in the liver and to a lesser extent in the kidneys (these are organs which are essential to glucose homeostasis); and that gluconeogenesis ends with glucose-6-phosphate and free glucose is not usually generated, but it can be, say after sleeping 8 hours (nighttime fast) or prolonged starvation. And finally we need to remember that the usual fate of glucose-6-phosphate is conversion into glycogen. Any glucose released will be used by the brain (but remember, the brain prefers ketone bodies for function if given a choice), or any other organ that needs glucose; there generally will not be enough glucose released to create a long chain fatty acid to be stored in the adipocyte, nor will the physiological signals be present to support this.
But we need to remember that the question pertains to the over consumption of fat, so we certainly aren't fasting in this scenario. Over consumption of fat is very difficult to do despite what everyone thinks. Now, I am not talking about eating a double cheeseburger with the bun along with a regular coke and fries; unfortunately a common meal out there these days. Which, by the way, also has an overabundance of carbohydrates. I'm referring to eating a bunch of bacon, sausage, butter, rib eye steaks, non lean burgers with cheese (with no bun or regular coke), or say four eggs or so...man, I'm beginning to drool...
Remember the scenario above with the eventual release of the glycerol backbone which could be converted into glucose (this, of course, is occurring intracellularly, not extracellularly). Now here's where we run into some trouble. Assuming one is a glutton and eats a mega amount of bacon, what is really going to happen. Yes, alot of fat was consumed; yes, there could be a large release of the glycerol backbone which can be converted to glucose-6-phosphate; will there be a release of glucose extracellularly or does there even need to be a release? Why can't the glucose-6-phosphate created just start shuttling down the glycolytic pathway to pyruvate, then to acetyl CoA and we all know the rest.
The answer lies in the fact that the signals for the creation of fatty acids will not be there. Remember, we ate no carbs and all fat (of course protein too which we'll analyze later). What are the signals needed? Overabundance of glucose (there is none), relative increase in insulin release (there was none), relative decrease in glucagon concentrations (the exact opposite occurred as more glucagon is secreted); so with an over consumption of fat it is still very difficult physiologically to get fat creation from fat consumption, so long as not too many carbs were consumed with the fat, as is the case in our scenario.
Another fact about eating alot of fat; fat consumption is a natural appetite suppressant. We think it has to do with the release of cholecystokinin, but the fact remains; when we eat alot of fat, we are fuller longer; satiety prevails. When we are fuller longer we dont eat as much..so we are giving the body nothing to store. Another problem our fat glutton runs into is either malabsorption of the fat or ensuing emesis due to their gluttonous behaviour, both of which will not allow any absorption of any of the fat at all.
So I guess my final answer is over consumption of fat could in theory lead to fat storage but it is extremely difficult to do since the biochemical signals favoring a glycolytic run into fat will not be favored when we over consume fat. (Can anyone say 'Run-on sentence' LOL)
Now let's look at protein over consumption;
Proteins are broken down into amino acids. These amino acids can be either glucogenic, ketogenic or have qualities of both glucogenic & ketogenic. Glucogenic amino acids will be converted into glucose and ketogenic amino acids can be converted into ketones or fatty acids. So right away we can see that over consumption of proteins containing predominantly ketogenic amino acids (only leucine and lysine are strictly ketogenic) can give rise to fatty acids. An amino acid is referred to as ketogenic if degradation gives rise to Acetyl CoA or Acetoacetyl CoA. These two species can be transformed to fatty acids as we discussed in an earlier post. Amino acids giving rise to pyruvate, oxaloacetate, fumarate, succinyl CoA or alphaketoglutarate are termed glucogenic as they can be used to create glucose. Fans of the Kreb's Cycle will immediately recognize oxaloacetate, fumarate, succinyl CoA and alphaketoglutarate as intermediaries in the Kreb's, a simple reminder that these amino acids are glucogenic.
I can certainly go through the degradation pathways of gluco/ketogenic amino acids, but I feel it is beyond the scope of this post :-) Of course I find it very exciting and anyone who wants to review the degradative pathways of amino acids further will be referred to pp. 690-696 of Stryer's (now really Berg, Tymoczko & Stryer) 7th Edition of Biochemistry, my personal favorite source for biochemical facts.
To summarize, we can see that it is quite difficult to create fat from the consumption of fat. Indeed this flies in the face of what most self-purported nutritional experts proselytize, that eating fat makes us fat; we see from a simple review that this is biochemically difficult to do. But over consumption of protein, in the form of the mixed or ketogenic amino acids will lead to the creation of fatty acids. But then this question is immediately raised by myself; since we over consumed protein to get to this stage; there will be low glucose, low insulin, increased glucagon, hence all the signals to favor B-oxidation of free fatty acids, not creation and storage of fats, so now we are right back to where we started...gosh I love this stuff :-)
Also, just as we will either vomit or poop out (mainly poop thank goodness) some of what we ate, a portion of our protein gluttony once again will not even have a chance for absorption. So while the question asked what happens when we over consume protein and/or fat and can this lead to the storage of fat, the short answer is that all depends and it depends mainly on us over consuming carbs with the protein/fat indulgence. Over consumption of fat/cholesterol without carbs can cause a fat buildup but is extremely unlikely due to the signals favoring fatty acid degradation and not storage.
I hope I didn't confuse anyone too much. Oh yeah, anyone know a good Brazilian Steak House on Long Island, NY. :-)
Have a great rest of what remains to our weekend everyone and as always thanks for reading and keep those biochemical questions coming!
dr jim
http://www.drjamescarlson.com/
Thanks so much for your very detailed response to my question. It is incredibly helpful, and I'm sharing it with pretty much everyone I know. One very brief follow-up question though, if you wouldn't mind indulging me:
Excess carbs obviously lead directly to storage. But is it not possible for the body to convert and store fat and/or protein as well? In other words, a normal/reasonable amount of fat, protein, and cholesterol won't lead to fat conversion and storage when that same amount of carbs would. However, is this still the case if one consumes a serious excess of fat protein and cholesterol? (as might happen, say, when I spend a few hours at my favorite Brazilian steakhouse, Fogo de Chao).
Much thanks once again!
Sean
Hi Sean,
No problem and I like your follow-up questions too; I'm going to think this through as I type and explain kinda like an impromptu lecture, so enjoy! :-)
It is possible for the body to store excess fat and protein consumption as fat. Here's how; we'll look at fats first;
When we consume fats we consume them usually in the form of triglycerides. A triglyceride is composed of 3 (three) fatty acid side chains (hence the tri) attached to a glycerol backbone. While beta-oxidation of the acyl side chains will release acetyl groups that will shuttle into the Kreb's, this will also release the glycerol backbone. The glycerol backbone can indeed be transformed to glucose via gluconeogenesis.
It needs to be re-emphasized that gluconeogenesis is not the reversal of glycolysis; that gluconeogenesis occurs mainly in the liver and to a lesser extent in the kidneys (these are organs which are essential to glucose homeostasis); and that gluconeogenesis ends with glucose-6-phosphate and free glucose is not usually generated, but it can be, say after sleeping 8 hours (nighttime fast) or prolonged starvation. And finally we need to remember that the usual fate of glucose-6-phosphate is conversion into glycogen. Any glucose released will be used by the brain (but remember, the brain prefers ketone bodies for function if given a choice), or any other organ that needs glucose; there generally will not be enough glucose released to create a long chain fatty acid to be stored in the adipocyte, nor will the physiological signals be present to support this.
But we need to remember that the question pertains to the over consumption of fat, so we certainly aren't fasting in this scenario. Over consumption of fat is very difficult to do despite what everyone thinks. Now, I am not talking about eating a double cheeseburger with the bun along with a regular coke and fries; unfortunately a common meal out there these days. Which, by the way, also has an overabundance of carbohydrates. I'm referring to eating a bunch of bacon, sausage, butter, rib eye steaks, non lean burgers with cheese (with no bun or regular coke), or say four eggs or so...man, I'm beginning to drool...
Remember the scenario above with the eventual release of the glycerol backbone which could be converted into glucose (this, of course, is occurring intracellularly, not extracellularly). Now here's where we run into some trouble. Assuming one is a glutton and eats a mega amount of bacon, what is really going to happen. Yes, alot of fat was consumed; yes, there could be a large release of the glycerol backbone which can be converted to glucose-6-phosphate; will there be a release of glucose extracellularly or does there even need to be a release? Why can't the glucose-6-phosphate created just start shuttling down the glycolytic pathway to pyruvate, then to acetyl CoA and we all know the rest.
The answer lies in the fact that the signals for the creation of fatty acids will not be there. Remember, we ate no carbs and all fat (of course protein too which we'll analyze later). What are the signals needed? Overabundance of glucose (there is none), relative increase in insulin release (there was none), relative decrease in glucagon concentrations (the exact opposite occurred as more glucagon is secreted); so with an over consumption of fat it is still very difficult physiologically to get fat creation from fat consumption, so long as not too many carbs were consumed with the fat, as is the case in our scenario.
Another fact about eating alot of fat; fat consumption is a natural appetite suppressant. We think it has to do with the release of cholecystokinin, but the fact remains; when we eat alot of fat, we are fuller longer; satiety prevails. When we are fuller longer we dont eat as much..so we are giving the body nothing to store. Another problem our fat glutton runs into is either malabsorption of the fat or ensuing emesis due to their gluttonous behaviour, both of which will not allow any absorption of any of the fat at all.
So I guess my final answer is over consumption of fat could in theory lead to fat storage but it is extremely difficult to do since the biochemical signals favoring a glycolytic run into fat will not be favored when we over consume fat. (Can anyone say 'Run-on sentence' LOL)
Now let's look at protein over consumption;
Proteins are broken down into amino acids. These amino acids can be either glucogenic, ketogenic or have qualities of both glucogenic & ketogenic. Glucogenic amino acids will be converted into glucose and ketogenic amino acids can be converted into ketones or fatty acids. So right away we can see that over consumption of proteins containing predominantly ketogenic amino acids (only leucine and lysine are strictly ketogenic) can give rise to fatty acids. An amino acid is referred to as ketogenic if degradation gives rise to Acetyl CoA or Acetoacetyl CoA. These two species can be transformed to fatty acids as we discussed in an earlier post. Amino acids giving rise to pyruvate, oxaloacetate, fumarate, succinyl CoA or alphaketoglutarate are termed glucogenic as they can be used to create glucose. Fans of the Kreb's Cycle will immediately recognize oxaloacetate, fumarate, succinyl CoA and alphaketoglutarate as intermediaries in the Kreb's, a simple reminder that these amino acids are glucogenic.
I can certainly go through the degradation pathways of gluco/ketogenic amino acids, but I feel it is beyond the scope of this post :-) Of course I find it very exciting and anyone who wants to review the degradative pathways of amino acids further will be referred to pp. 690-696 of Stryer's (now really Berg, Tymoczko & Stryer) 7th Edition of Biochemistry, my personal favorite source for biochemical facts.
To summarize, we can see that it is quite difficult to create fat from the consumption of fat. Indeed this flies in the face of what most self-purported nutritional experts proselytize, that eating fat makes us fat; we see from a simple review that this is biochemically difficult to do. But over consumption of protein, in the form of the mixed or ketogenic amino acids will lead to the creation of fatty acids. But then this question is immediately raised by myself; since we over consumed protein to get to this stage; there will be low glucose, low insulin, increased glucagon, hence all the signals to favor B-oxidation of free fatty acids, not creation and storage of fats, so now we are right back to where we started...gosh I love this stuff :-)
Also, just as we will either vomit or poop out (mainly poop thank goodness) some of what we ate, a portion of our protein gluttony once again will not even have a chance for absorption. So while the question asked what happens when we over consume protein and/or fat and can this lead to the storage of fat, the short answer is that all depends and it depends mainly on us over consuming carbs with the protein/fat indulgence. Over consumption of fat/cholesterol without carbs can cause a fat buildup but is extremely unlikely due to the signals favoring fatty acid degradation and not storage.
I hope I didn't confuse anyone too much. Oh yeah, anyone know a good Brazilian Steak House on Long Island, NY. :-)
Have a great rest of what remains to our weekend everyone and as always thanks for reading and keep those biochemical questions coming!
dr jim
http://www.drjamescarlson.com/
Sunday, February 5, 2012
Great Questions From a Future Doctor!
I always love when I receive a question from a future doc about proper nutrition. It is exciting to me because I know once I explain the correct way to eat, dispelling the many myths that surround nutritional science, I have just not only educated one person, but the tens of thousands of patients this future doc is going to meet over the course of their career.
As a side note, I have been in practice for 20 years. At about 35 patients a day, sometimes more, never less; I have easily had over a 130,000 patient contacts. Yes, you read those numbers right :-) So just imagine how excited I get given a chance to properly educate a future doc on the right way to eat. His question is italicized below and my answer will follow;
Dear Dr. Jim,
Hello! I recently stumbled upon your blog and found it to be a quite useful source of information. I'm an Army Officer and graduate student headed to medical school next year. One of my major responsibilities in the Army has been to ensure the health and physical fitness of my Soldiers. So I've been trying to gain a better grasp of nutrition science, but much of what I've read I've found to be apocryphal, even from so-called nutrition experts.
In any case, I had a question I thought perhaps you might be willing to answer on your blog. I am curious about the rate and efficiency of food absorption and processing.
In short: if one eats a "normal" American meal made up of protein, fats, and carbohydrates, how long does it take for those excess calories one eats to be absorbed, transported, and stored as fat?
On a related note, how efficient is this process? I'm thinking of this in the context of individuals who are trying to lose weight by lowering their calorie intake. If over the course of the week a person (baseline 2500 calories/day) diets at about 1800 calories per day, but then on one of those days "slips up" and consumes a whopping 6000 calories, is that basically the same as consuming 2370 calories per day over the course of that week or, given the huge volume of food, would some of the nutrients during that 6000-calorie-feast pass through the gut without being absorbed?
Thank you for your time!
Very best regards,
S.W.
Dear S.W.
Thanks so much for your intriguing questions about nutrition. Apocryphal is indeed the case when trying to weed through all the hoopla concerning the right way to eat. Over the years I have come to view the term 'nutritonal-expert' as an oxymoron, as most of them haven't a clue about the correct way to eat. Sure, they can recite the glycolytic pathway faster than a match can burn down to their finger; but they really haven't stopped to view the pathways in an integrated fashion, the way these pathways should be viewed. This I attribute to inadequate academic training which still unfortunately persists today, and the tenacious, vehement denial by these 'experts' that we have the biochemical understanding to basically eradicate obesity, type 2 diabetes, heart disease, GERD and many types of cancers TODAY!
To understand that plaque-forming deadly cholesterol and fat production starts with a sugar molecule (glucose & fructose), requires an understanding that the pyruvate we arrive at when glycolysis ends and the subsequent acetyl-CoA that's formed, that not all this acetyl-CoA is shuttled into the Kreb's with the oxidative phosphorylation pathway ending it all. No, that's not the case.
(Don't worry, I'll get to your questions in a bit :-)
I was under the impression when I studied biochemistry & molecular cellular biology in my undergraduate years that it went like this--Glycolysis----Kreb's----Oxidative Phosphorylation---the end. I wasn't told that AcetylCoA is a pivotal bio-molecule and while it can be shuttled to the Kreb's, there were indeed other fates for AcetylCoA. Like condensation of 2 AcetylCoA molecules to get acetoacetyl CoA the starting point for both cholesterol and fatty acid synthesis. I wasn't told that insulin actually acts to increase the creation of HMG CoA reductase by increasing its actual gene expression, thereby creating more of this rate-limiting enzyme, the end result being production of more cholesterol. While I knew the biochemistry behind the creation of fatty acids and I knew it started with , once again, acetylCoA; the integration of all the possible fates of acetylCoA were not taught to me; I had to put that all together myself many years later as a practicing physician. On top of all this, it was never really stressed to me that insulin performs many different biochemical activities in our cells.
Sure, everyone knows insulin is needed to get glucose inside the cell, but as I mentioned above; who remembers that insulin increases HMG-CoA reductases's actual gene expression; that insulin allosterically activates acetyl CoA carboxylase (via dephosphorylation of the enzyme) stimulating an increase in free fatty acid production; that insulin works via a second-messenger sysytem and that one of these messengers DAG (diacylglycerol) has an arachidonic acid side chain that when undergoing degradation helps gives rise to inflammatory and cancer causing mediators and the list goes on and on. In fact, I refer to insulin as 'the dirty little hormone' in my book. Sure, we need it to survive, but very little of this peptide hormone is needed for optimum health...very little.
So let's get to your first question...
In short: if one eats a "normal" American meal made up of protein, fats, and carbohydrates, how long does it take for those excess calories one eats to be absorbed, transported, and stored as fat?
In short, it takes about 8-10 hours for our bodies to create and store fat. When a mix of food is eaten in a 'typical' American diet, it is almost always an overabundance of carbohydrates. Now we need to understand that ALL carbohydrates no matter their source, are broken down into the simple sugar glucose and it is glucose that gets stored as fat in the fat cell or adipocyte as it's called. To create & store fat requires the presence of insulin which will activate the acetylCoA carboxylase enzyme as mentioned above encouraging the biosynthesis of fatty acids with the subsequent storage in the fat cell.
Hence, overeat carbohydrates in any form and I mean ANY form, such as whole grains, multi grains, 7-grains, whole wheat pasta, brown rice, fruit (fructose gets stored quicker than glucose as it needs LESS modification) yogurt or oatmeal and you will create and store pounds and pounds of fat.
But wait, i hear some of you yelling...'What about glycogen? Doesn't the body create glycogen stores first and then go on to store the excess as fat.?!?!'
While that is true, the typical American diet is so overloaded with carbs that all the signals for fat storage are set into play. That is, eat too many carbs (easy to do), secrete insulin, glucose gets shuttled doen the glycolytic pathway, more acetyl CoA is created, more substrate that acetylCoA reductase has to work with and since insulin has been secreted by the carb laden meal, increased activity of acetylCoA reductase occurs.
Said bluntly-Eat too many carbs, in any shape or form...get heavier. Did I forget to mention that while over eating carbs will increase your creation and storage of fat; it will also result in the increased production of plaque-forming deadly cholesterol as well. So, in a nut-shell; eat more carbs, you get heavier and increase your risk not only of heart disease but many other disease-processes.
Let me also state the fact that ALL one's carbohydrate needs can be met by eating protein, fat & cholesterol containing foods, without the need to even consume carbs. Of note, the glucogenic amino acids, as well as the glycerol backbone chain from triglycerides can be used to create glucose; there are also many examples of societies that eat predominately fat and protein and have low rates of heart disease, type 2 diabetes &cancer (the Inuits are such an example), despite the fact that they are eating what the 'nutritonal experts' around the world tell us not to eat.
Ahhh, you have mentioned my all-time Nemesis....The Calorie!
Arrrrgggghhhhh!!!!!!!
As chapter 6 in my book states "Calories are irrelevant in Human nutrition." Remember that a calorie is defined as the amount of heat needed to raise the temperature of 1 gram of H20 by 1 degree Celsius and that the calorie is important only if you are a heat biochemist. The calorie is measured by a combustion process. When we eat a piece of meat, it doesn't go into our stomach and burn (via a combustion process) it is 'digested' and I cannot emphasize enough that combustion and digestion are two entirely different processes.
Now when we eat excess 'calories' we are really not overeating heat (sounds kinda silly when I put it like that), we are overeating carbohydrates; and it is these carbohydrates in the form of glucose that the body will store. Our bodies don't store calories, we store glucose biochemically altered into fatty acid molecules. It took me a very long time to understand the calorie is irrelevant in human nutrition and to this day I'll slip and use the word burn or whatnot; but please always remember that counting calories are an utter waste of time, a red-herring at best.
Which of course all this talk about that nefarious calorie is a nice segue into your next question...
On a related note, how efficient is this process? I'm thinking of this in the context of individuals who are trying to lose weight by lowering their calorie intake. If over the course of the week a person (baseline 2500 calories/day) diets at about 1800 calories per day, but then on one of those days "slips up" and consumes a whopping 6000 calories, is that basically the same as consuming 2370 calories per day over the course of that week or, given the huge volume of food, would some of the nutrients during that 6000-calorie-feast pass through the gut without being absorbed?
Seems like a loaded question. Reminds me of those algebraic problems I saw in high school..."if Jimmy is on a train headed north-northwest at a speed of 60 mph and a tail wind is hitting the train at 5 mph, but Jimmy is hopping backwards on one foot in a cross diagonal pattern, how long will it take before Jimmy's gastrocnemius claudicates....?' Huh?
Alright, back to the question.
Since we just learned calories mean nothing in human nutrition, we can just multiply all your numbers by 0 to get 0. In other words, once we understand calories are irrelevant and that it is the grams of carbs that are important, the whole question itself becomes irrelevant. You see, we aren't storing calories at all, but the simple sugar glucose from the carbs. Sure, one can place the food items in question which comprise the calories mentioned into a calorimeter, burn it and see how much heat is being given off; it will tell us nothing about what is really happening in human nutrition, specifically with weight loss.
Let's use a clinical scenario. It took me awhile to realize that my morbidly obese patients actually increased their calories before weight loss kicked in. I didn't realize this because I was focused on carb intake, not calories. The patient who brought this to my attention was over 500 LBs and came in all distressed one day. When i asked him why he told me that he was consuming 4x the amount of calories he was consuming before (2500 to now 10,000 a day!) and his problem was that he was wondering Why he was LOSING weight?!
He confessed he did not increase his exercise at all and despite quadrupling his caloric intake HE WAS LOSING WEIGHT!!!! This was my Eureka! moment when I started to actually count calories and carbs on my patients. What was actually happening is that in my morbidly obese patients, they were often doubling, tripling their caloric intakes before they saw an appreciable weight loss, but they were not increasing the calories via carbs, but by the consumption of more fatty & cholesterol containing foods. As weight loss progressed, the calorie intake was lower and lower, but the calories always took the form of more fat, cholesterol & protein, NOT carbs.
Ask any morbidly obese patients and they'll tell you flat out "I've tried everything, even starving myself and I can't lose weight." Most obese patients do calorie restrict, but since calories mean nothing the end result will be failure; and those who do lose weight, since they almost always are eating a non sustainable low fat low cholesterol diet, will fall off this dietary path, having to start all over again, unfortunately oftentimes still thinking they are heavy due to over consumption of calories and fat.
So for your patients who say, eat 6000 calories a day up from say the 1800 or so, it all depends on what they ate exactly. If those calories were mainly in the form of carbs, they will store and gain weight; if it was in the form of more fat and cholesterol, the biochemical signals will not favor storage and they will not really see an appreciable weight gain if any. And that is why to answer that question we need to know exactly what the foods were that got the person to 6000 calories.
Hope that helps!
Hey, my fingers are getting tired and I have to get a few low carb beers on ice so I can watch the Giants win the Superbowel in a couple of hours!
I hope my explanations helped not only for your personal understanding, but to make and keep our troops the healthiest in the world! Thanks again for asking some very important questions about human nutrition! And CONGRATULATIONS upon your acceptance into Medical School, maybe I'll be teaching your nutritional biochemistry course :-)
drjim :-)
http://www.drjamescarlson.com/
As a side note, I have been in practice for 20 years. At about 35 patients a day, sometimes more, never less; I have easily had over a 130,000 patient contacts. Yes, you read those numbers right :-) So just imagine how excited I get given a chance to properly educate a future doc on the right way to eat. His question is italicized below and my answer will follow;
Dear Dr. Jim,
Hello! I recently stumbled upon your blog and found it to be a quite useful source of information. I'm an Army Officer and graduate student headed to medical school next year. One of my major responsibilities in the Army has been to ensure the health and physical fitness of my Soldiers. So I've been trying to gain a better grasp of nutrition science, but much of what I've read I've found to be apocryphal, even from so-called nutrition experts.
In any case, I had a question I thought perhaps you might be willing to answer on your blog. I am curious about the rate and efficiency of food absorption and processing.
In short: if one eats a "normal" American meal made up of protein, fats, and carbohydrates, how long does it take for those excess calories one eats to be absorbed, transported, and stored as fat?
On a related note, how efficient is this process? I'm thinking of this in the context of individuals who are trying to lose weight by lowering their calorie intake. If over the course of the week a person (baseline 2500 calories/day) diets at about 1800 calories per day, but then on one of those days "slips up" and consumes a whopping 6000 calories, is that basically the same as consuming 2370 calories per day over the course of that week or, given the huge volume of food, would some of the nutrients during that 6000-calorie-feast pass through the gut without being absorbed?
Thank you for your time!
Very best regards,
S.W.
Dear S.W.
Thanks so much for your intriguing questions about nutrition. Apocryphal is indeed the case when trying to weed through all the hoopla concerning the right way to eat. Over the years I have come to view the term 'nutritonal-expert' as an oxymoron, as most of them haven't a clue about the correct way to eat. Sure, they can recite the glycolytic pathway faster than a match can burn down to their finger; but they really haven't stopped to view the pathways in an integrated fashion, the way these pathways should be viewed. This I attribute to inadequate academic training which still unfortunately persists today, and the tenacious, vehement denial by these 'experts' that we have the biochemical understanding to basically eradicate obesity, type 2 diabetes, heart disease, GERD and many types of cancers TODAY!
To understand that plaque-forming deadly cholesterol and fat production starts with a sugar molecule (glucose & fructose), requires an understanding that the pyruvate we arrive at when glycolysis ends and the subsequent acetyl-CoA that's formed, that not all this acetyl-CoA is shuttled into the Kreb's with the oxidative phosphorylation pathway ending it all. No, that's not the case.
(Don't worry, I'll get to your questions in a bit :-)
I was under the impression when I studied biochemistry & molecular cellular biology in my undergraduate years that it went like this--Glycolysis----Kreb's----Oxidative Phosphorylation---the end. I wasn't told that AcetylCoA is a pivotal bio-molecule and while it can be shuttled to the Kreb's, there were indeed other fates for AcetylCoA. Like condensation of 2 AcetylCoA molecules to get acetoacetyl CoA the starting point for both cholesterol and fatty acid synthesis. I wasn't told that insulin actually acts to increase the creation of HMG CoA reductase by increasing its actual gene expression, thereby creating more of this rate-limiting enzyme, the end result being production of more cholesterol. While I knew the biochemistry behind the creation of fatty acids and I knew it started with , once again, acetylCoA; the integration of all the possible fates of acetylCoA were not taught to me; I had to put that all together myself many years later as a practicing physician. On top of all this, it was never really stressed to me that insulin performs many different biochemical activities in our cells.
Sure, everyone knows insulin is needed to get glucose inside the cell, but as I mentioned above; who remembers that insulin increases HMG-CoA reductases's actual gene expression; that insulin allosterically activates acetyl CoA carboxylase (via dephosphorylation of the enzyme) stimulating an increase in free fatty acid production; that insulin works via a second-messenger sysytem and that one of these messengers DAG (diacylglycerol) has an arachidonic acid side chain that when undergoing degradation helps gives rise to inflammatory and cancer causing mediators and the list goes on and on. In fact, I refer to insulin as 'the dirty little hormone' in my book. Sure, we need it to survive, but very little of this peptide hormone is needed for optimum health...very little.
So let's get to your first question...
In short: if one eats a "normal" American meal made up of protein, fats, and carbohydrates, how long does it take for those excess calories one eats to be absorbed, transported, and stored as fat?
In short, it takes about 8-10 hours for our bodies to create and store fat. When a mix of food is eaten in a 'typical' American diet, it is almost always an overabundance of carbohydrates. Now we need to understand that ALL carbohydrates no matter their source, are broken down into the simple sugar glucose and it is glucose that gets stored as fat in the fat cell or adipocyte as it's called. To create & store fat requires the presence of insulin which will activate the acetylCoA carboxylase enzyme as mentioned above encouraging the biosynthesis of fatty acids with the subsequent storage in the fat cell.
Hence, overeat carbohydrates in any form and I mean ANY form, such as whole grains, multi grains, 7-grains, whole wheat pasta, brown rice, fruit (fructose gets stored quicker than glucose as it needs LESS modification) yogurt or oatmeal and you will create and store pounds and pounds of fat.
But wait, i hear some of you yelling...'What about glycogen? Doesn't the body create glycogen stores first and then go on to store the excess as fat.?!?!'
While that is true, the typical American diet is so overloaded with carbs that all the signals for fat storage are set into play. That is, eat too many carbs (easy to do), secrete insulin, glucose gets shuttled doen the glycolytic pathway, more acetyl CoA is created, more substrate that acetylCoA reductase has to work with and since insulin has been secreted by the carb laden meal, increased activity of acetylCoA reductase occurs.
Said bluntly-Eat too many carbs, in any shape or form...get heavier. Did I forget to mention that while over eating carbs will increase your creation and storage of fat; it will also result in the increased production of plaque-forming deadly cholesterol as well. So, in a nut-shell; eat more carbs, you get heavier and increase your risk not only of heart disease but many other disease-processes.
Let me also state the fact that ALL one's carbohydrate needs can be met by eating protein, fat & cholesterol containing foods, without the need to even consume carbs. Of note, the glucogenic amino acids, as well as the glycerol backbone chain from triglycerides can be used to create glucose; there are also many examples of societies that eat predominately fat and protein and have low rates of heart disease, type 2 diabetes &cancer (the Inuits are such an example), despite the fact that they are eating what the 'nutritonal experts' around the world tell us not to eat.
Ahhh, you have mentioned my all-time Nemesis....The Calorie!
Arrrrgggghhhhh!!!!!!!
As chapter 6 in my book states "Calories are irrelevant in Human nutrition." Remember that a calorie is defined as the amount of heat needed to raise the temperature of 1 gram of H20 by 1 degree Celsius and that the calorie is important only if you are a heat biochemist. The calorie is measured by a combustion process. When we eat a piece of meat, it doesn't go into our stomach and burn (via a combustion process) it is 'digested' and I cannot emphasize enough that combustion and digestion are two entirely different processes.
Now when we eat excess 'calories' we are really not overeating heat (sounds kinda silly when I put it like that), we are overeating carbohydrates; and it is these carbohydrates in the form of glucose that the body will store. Our bodies don't store calories, we store glucose biochemically altered into fatty acid molecules. It took me a very long time to understand the calorie is irrelevant in human nutrition and to this day I'll slip and use the word burn or whatnot; but please always remember that counting calories are an utter waste of time, a red-herring at best.
Which of course all this talk about that nefarious calorie is a nice segue into your next question...
On a related note, how efficient is this process? I'm thinking of this in the context of individuals who are trying to lose weight by lowering their calorie intake. If over the course of the week a person (baseline 2500 calories/day) diets at about 1800 calories per day, but then on one of those days "slips up" and consumes a whopping 6000 calories, is that basically the same as consuming 2370 calories per day over the course of that week or, given the huge volume of food, would some of the nutrients during that 6000-calorie-feast pass through the gut without being absorbed?
Seems like a loaded question. Reminds me of those algebraic problems I saw in high school..."if Jimmy is on a train headed north-northwest at a speed of 60 mph and a tail wind is hitting the train at 5 mph, but Jimmy is hopping backwards on one foot in a cross diagonal pattern, how long will it take before Jimmy's gastrocnemius claudicates....?' Huh?
Alright, back to the question.
Since we just learned calories mean nothing in human nutrition, we can just multiply all your numbers by 0 to get 0. In other words, once we understand calories are irrelevant and that it is the grams of carbs that are important, the whole question itself becomes irrelevant. You see, we aren't storing calories at all, but the simple sugar glucose from the carbs. Sure, one can place the food items in question which comprise the calories mentioned into a calorimeter, burn it and see how much heat is being given off; it will tell us nothing about what is really happening in human nutrition, specifically with weight loss.
Let's use a clinical scenario. It took me awhile to realize that my morbidly obese patients actually increased their calories before weight loss kicked in. I didn't realize this because I was focused on carb intake, not calories. The patient who brought this to my attention was over 500 LBs and came in all distressed one day. When i asked him why he told me that he was consuming 4x the amount of calories he was consuming before (2500 to now 10,000 a day!) and his problem was that he was wondering Why he was LOSING weight?!
He confessed he did not increase his exercise at all and despite quadrupling his caloric intake HE WAS LOSING WEIGHT!!!! This was my Eureka! moment when I started to actually count calories and carbs on my patients. What was actually happening is that in my morbidly obese patients, they were often doubling, tripling their caloric intakes before they saw an appreciable weight loss, but they were not increasing the calories via carbs, but by the consumption of more fatty & cholesterol containing foods. As weight loss progressed, the calorie intake was lower and lower, but the calories always took the form of more fat, cholesterol & protein, NOT carbs.
Ask any morbidly obese patients and they'll tell you flat out "I've tried everything, even starving myself and I can't lose weight." Most obese patients do calorie restrict, but since calories mean nothing the end result will be failure; and those who do lose weight, since they almost always are eating a non sustainable low fat low cholesterol diet, will fall off this dietary path, having to start all over again, unfortunately oftentimes still thinking they are heavy due to over consumption of calories and fat.
So for your patients who say, eat 6000 calories a day up from say the 1800 or so, it all depends on what they ate exactly. If those calories were mainly in the form of carbs, they will store and gain weight; if it was in the form of more fat and cholesterol, the biochemical signals will not favor storage and they will not really see an appreciable weight gain if any. And that is why to answer that question we need to know exactly what the foods were that got the person to 6000 calories.
Hope that helps!
Hey, my fingers are getting tired and I have to get a few low carb beers on ice so I can watch the Giants win the Superbowel in a couple of hours!
I hope my explanations helped not only for your personal understanding, but to make and keep our troops the healthiest in the world! Thanks again for asking some very important questions about human nutrition! And CONGRATULATIONS upon your acceptance into Medical School, maybe I'll be teaching your nutritional biochemistry course :-)
drjim :-)
http://www.drjamescarlson.com/
Saturday, February 4, 2012
You were Right-They were Wrong
Here is an e-mail I just received today that I want to share with everyone...
Dr. Jim,
You are going to love this story!
Last August, I had my blood tested and was shocked to hear the results.
August
Non-HDL 178
TRI 104
LDL 157
HDL 54
Total Chol 232
I insisted the lab must have made a mistake. For most of my adult life, I have eaten a no pig, no cow, low sodium, low fat, no caffeine diet. I exercise regularly and look very fit. Most people cannot believe I am in my 50s. My Doctor told me that high cholesterol is often an inherited trait and there might not be much I can do about it. In fact, I was already pretty much following the diet he would recommend. I could try to cut back on the eggs and cheese, but there was "probably not much more that could be done with my diet at this point." We would do the test again in 6 months, but I should be prepared for a future that included statins. Did I mention I hate to take drugs? Well I do.
Purely coincidentally, my husband had been listening to you on a local health radio program in Dallas at about the same time. He told me about it, so I started surfing the internet until I found you. As a person with a math and science background, I was swayed by your detailed explanations and immediately changed to a low carb diet. I confess I still do no pig, no cow, but I added more fat - mostly nuts & cheese.
After the switch, I mentioned to one of my sisters that I was doing the low carb thing to get my cholesterol down. She quickly cut me off and proclaimed there was nothing I could do, because it really is "all hereditary". (As an aside... I don't make it a habit to take medical advice from a lawyer even if we do have the same parents that both had high cholesterol.)
Well I just had my blood retested for the first time since going low-carb. Here are the results compared to my August numbers. (I know you won't be surprised.)
August 2011 Feb. 2012
Non-HDL 178 121
TRI 104 41
LDL 157 113
HDL 54 58
Total 232 179
My doctor called me amazed. He really didn't think results like that could be achieved by changing your diet. He confessed that before getting the result, he had warned my husband that I was likely to be disappointed. So he implored me to tell him what I had done to achieve these results. I told him that I just did what Dr. Carlson recommends. I cut out the gratuitous carbs and ate more fats and eggs. I shifted my fruits and vegetables from mostly fruits to mostly vegetables and I try to make sure my carbs are the high fiber kind.
I suggested he put his prescription pad away and start handing out your book.
Thanks for putting it all out there on the web for us.
m.j.
Dr. Jim,
You are going to love this story!
Last August, I had my blood tested and was shocked to hear the results.
August
Non-HDL 178
TRI 104
LDL 157
HDL 54
Total Chol 232
I insisted the lab must have made a mistake. For most of my adult life, I have eaten a no pig, no cow, low sodium, low fat, no caffeine diet. I exercise regularly and look very fit. Most people cannot believe I am in my 50s. My Doctor told me that high cholesterol is often an inherited trait and there might not be much I can do about it. In fact, I was already pretty much following the diet he would recommend. I could try to cut back on the eggs and cheese, but there was "probably not much more that could be done with my diet at this point." We would do the test again in 6 months, but I should be prepared for a future that included statins. Did I mention I hate to take drugs? Well I do.
Purely coincidentally, my husband had been listening to you on a local health radio program in Dallas at about the same time. He told me about it, so I started surfing the internet until I found you. As a person with a math and science background, I was swayed by your detailed explanations and immediately changed to a low carb diet. I confess I still do no pig, no cow, but I added more fat - mostly nuts & cheese.
After the switch, I mentioned to one of my sisters that I was doing the low carb thing to get my cholesterol down. She quickly cut me off and proclaimed there was nothing I could do, because it really is "all hereditary". (As an aside... I don't make it a habit to take medical advice from a lawyer even if we do have the same parents that both had high cholesterol.)
Well I just had my blood retested for the first time since going low-carb. Here are the results compared to my August numbers. (I know you won't be surprised.)
August 2011 Feb. 2012
Non-HDL 178 121
TRI 104 41
LDL 157 113
HDL 54 58
Total 232 179
My doctor called me amazed. He really didn't think results like that could be achieved by changing your diet. He confessed that before getting the result, he had warned my husband that I was likely to be disappointed. So he implored me to tell him what I had done to achieve these results. I told him that I just did what Dr. Carlson recommends. I cut out the gratuitous carbs and ate more fats and eggs. I shifted my fruits and vegetables from mostly fruits to mostly vegetables and I try to make sure my carbs are the high fiber kind.
I suggested he put his prescription pad away and start handing out your book.
Thanks for putting it all out there on the web for us.
m.j.
Friday, February 3, 2012
Dr. Oz Truly is The Bane of My Existence!
Definitions of bane from American Heritage Dictionary;
1.Fatal injury or ruin: "Hath some fond lover tic'd thee to thy bane?" (George Herbert).
2.
a. A cause of harm, ruin, or death: "Obedience,/Bane of all genius, virtue, freedom, truth,/Makes slaves of men" (Percy Bysshe Shelley).
b. A source of persistent annoyance or exasperation:
3. A deadly poison.
Sorry Dr. Oz, but it's true. You fit precisely with definition 2 b (or not 2 b, sorry, couldn't resist. Definition 3 could easily pertain to the consumption of carbs, but I'm here mainly to vent out my frustrations against Dr. Oz)
Whenever I have a chance to peruse his show I always get this sinking feeling in the pit of my stomach that millions of viewers are watching him & believing the nutritional nonsense he spews forward & then I pace back & forth, back & forth and wonder why this guys on television and then my auditory hallucinations start again and all I hear is the repetitive mantra Oprah...Oprah...Oprah (I know that was a run-on sentence so just put your red pens down and follow me on this one :-)
The latest comments from and about his show are how he is promoting baryatric surgery as the be-all-end-all solution to weight loss and as a diabetes cure to name a few. While my patients know I am not against gastric bypass and/or the lap band (we now have a gastric sleeve procedure to add into the mix) as a 'tool' to help facilitate weight-loss; everyone needs to understand that this surgical option should not be promoted as first-line therapy.
So long as Dr. Oz continues to disseminate the incorrect way to eat, millions of people will continue to believe that low-fat, low-cholesterol is the right way to eat. The end result will be exactly what we physicians continue to see on a daily basis; people getting heavier, cholesterol panels getting worse, blood sugars & pressures going higher and the list goes on and on.
A few weeks back when I was unlucky enough to come across his show..ok I was channel surfing and I heard someone mentioning L-arginine and my biochemical ears became pointy and my fingers immediately came off the channel up button and there it was...the Dr Oz show. He was talking about L-arginine and how it can help increase the pituitary's production & secretion of Growth Hormone, which, by the way, it cannot and this was shown in studies performed years ago. I then wondered why anyone would even mention the L in front of arginine as the only arginine our bodies can utilize is the L version so its superfluous to even say 'L'-arginine. It only suggests to me that that person just wants to look clever in the eyes of others. (As an aside the letter L is a designation of the chirality of particles, that is, bio molecules can have mirror images of one another referred to as enantiomers, the mirror image of the L is the D molecule go do an Internet search to learn more if you wish)
Anyway, my point is that I just happened across his show, heard an amino-acid mentioned, noticed it was the Dr Oz show and couldn't stop myself from watching. A good analogy here is like when you are cleaning out your refrigerator (finally) and you come across that Tupperware container you know you put in there about a year ago; you simply cannot discern for the life of you what once resided in there, you just know it's been there for about a year; and you must, just must take the top off and smell what now remains before discarding the decomposed organic remnants into 5 thick padded garbage bags, immediately rushing these hermetically sealed bags outside to the garbage for fear your smoke detectors will go off due to the thick pungent odor you can cut with a knife;; then worrying you might have to explain to fire rescue what that 'terrible odor' is....ok, I think I've made my point.
The fact of the matter is I actually like Dr. Oz, but I vehemently opine he should not be attempting to educate us on any way to eat. But then of course why should I be picking on Dr. Oz? The vast majority of doctors, nutritionists, dietitians and just about every self-proclaimed health guru promotes the low-fat, low-cholesterol dietary myth, so now I guess I've come full circle....
I guess what's happening is that I am just sick & tired of people promoting the wrong dietary message and believing in it's so-called virtues, despite the fact that we are getting heavier, still dying from heart disease and the complications of diabetes and failing to see 'the emperor's new clothes' for what they really are.
As I've implored many times in the past....
"When will it all end?"
I really do not know.
OK, my dogs need to go outside and i need to figure out what I'm going to eat for lunch today before i work out later with my beautiful & wonderful wife Gloria; yes, I have actually started to train once again....could body-building Jim, er, Dr. Jim be making a come-back? You all just have to wait and see :-) Have a great weekend everyone!
And before I forget......GO GIANTS!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
dr jim
http://www.drjamescarlson.com/
1.Fatal injury or ruin: "Hath some fond lover tic'd thee to thy bane?" (George Herbert).
2.
a. A cause of harm, ruin, or death: "Obedience,/Bane of all genius, virtue, freedom, truth,/Makes slaves of men" (Percy Bysshe Shelley).
b. A source of persistent annoyance or exasperation:
3. A deadly poison.
Sorry Dr. Oz, but it's true. You fit precisely with definition 2 b (or not 2 b, sorry, couldn't resist. Definition 3 could easily pertain to the consumption of carbs, but I'm here mainly to vent out my frustrations against Dr. Oz)
Whenever I have a chance to peruse his show I always get this sinking feeling in the pit of my stomach that millions of viewers are watching him & believing the nutritional nonsense he spews forward & then I pace back & forth, back & forth and wonder why this guys on television and then my auditory hallucinations start again and all I hear is the repetitive mantra Oprah...Oprah...Oprah (I know that was a run-on sentence so just put your red pens down and follow me on this one :-)
The latest comments from and about his show are how he is promoting baryatric surgery as the be-all-end-all solution to weight loss and as a diabetes cure to name a few. While my patients know I am not against gastric bypass and/or the lap band (we now have a gastric sleeve procedure to add into the mix) as a 'tool' to help facilitate weight-loss; everyone needs to understand that this surgical option should not be promoted as first-line therapy.
So long as Dr. Oz continues to disseminate the incorrect way to eat, millions of people will continue to believe that low-fat, low-cholesterol is the right way to eat. The end result will be exactly what we physicians continue to see on a daily basis; people getting heavier, cholesterol panels getting worse, blood sugars & pressures going higher and the list goes on and on.
A few weeks back when I was unlucky enough to come across his show..ok I was channel surfing and I heard someone mentioning L-arginine and my biochemical ears became pointy and my fingers immediately came off the channel up button and there it was...the Dr Oz show. He was talking about L-arginine and how it can help increase the pituitary's production & secretion of Growth Hormone, which, by the way, it cannot and this was shown in studies performed years ago. I then wondered why anyone would even mention the L in front of arginine as the only arginine our bodies can utilize is the L version so its superfluous to even say 'L'-arginine. It only suggests to me that that person just wants to look clever in the eyes of others. (As an aside the letter L is a designation of the chirality of particles, that is, bio molecules can have mirror images of one another referred to as enantiomers, the mirror image of the L is the D molecule go do an Internet search to learn more if you wish)
Anyway, my point is that I just happened across his show, heard an amino-acid mentioned, noticed it was the Dr Oz show and couldn't stop myself from watching. A good analogy here is like when you are cleaning out your refrigerator (finally) and you come across that Tupperware container you know you put in there about a year ago; you simply cannot discern for the life of you what once resided in there, you just know it's been there for about a year; and you must, just must take the top off and smell what now remains before discarding the decomposed organic remnants into 5 thick padded garbage bags, immediately rushing these hermetically sealed bags outside to the garbage for fear your smoke detectors will go off due to the thick pungent odor you can cut with a knife;; then worrying you might have to explain to fire rescue what that 'terrible odor' is....ok, I think I've made my point.
The fact of the matter is I actually like Dr. Oz, but I vehemently opine he should not be attempting to educate us on any way to eat. But then of course why should I be picking on Dr. Oz? The vast majority of doctors, nutritionists, dietitians and just about every self-proclaimed health guru promotes the low-fat, low-cholesterol dietary myth, so now I guess I've come full circle....
I guess what's happening is that I am just sick & tired of people promoting the wrong dietary message and believing in it's so-called virtues, despite the fact that we are getting heavier, still dying from heart disease and the complications of diabetes and failing to see 'the emperor's new clothes' for what they really are.
As I've implored many times in the past....
"When will it all end?"
I really do not know.
OK, my dogs need to go outside and i need to figure out what I'm going to eat for lunch today before i work out later with my beautiful & wonderful wife Gloria; yes, I have actually started to train once again....could body-building Jim, er, Dr. Jim be making a come-back? You all just have to wait and see :-) Have a great weekend everyone!
And before I forget......GO GIANTS!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
dr jim
http://www.drjamescarlson.com/
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