Sport Dispelling some myths about protein and carbs

[IWalkAlone]

My top 3 nutrition myths. These are for natural lifters. If you are not natural, different rules may apply. Feel free to add your own!
1. Cutting carbs will make you lose fat. NOT TRUE. Cutting calories will. Since carbs and protein have the same number of calories per gram (4), cutting 100 grams of carbs from your diet and replacing them with 100 grams of protein will lead to ZERO pounds lost. What it will lead to is poor memory, immune function, endocrine function and metabolic function, as carbs are needed to power these systems.

2. You need 1-1.5 grams of protein to build or retain muscle. NOT TRUE! Studies indicate that lean muscle can be added with as little as 1 gram per kg of lean body weight and that above 0.8 grams per pound of body weight is unnecessary. Simply put, more than a gram of protein will provide no better results, but may be stored as fat, as any extra calories may be that aren't utilized.

3. You can only absorb XXX grams of protein in one sitting. Again, NOT TRUE. But what you can absorb and what you need (especially post-workout) are totally different. At least one study found that more than 20 grams of protein PWO was completely unnecessary. The same study showed that there was no difference to muscle tissue repair or hormone levels between 20 g and 40 g. From AmJClinNutr. 2009 Jan; 89(1):161-8: "Ingestion of 20 g of intact protein is sufficient to maximally stimulate MPS (response of muscle) and APS (albumin protein synthesis) after resistance exercise." Another article recommends that protein consumption is irrelevant and that supplentation of 0.1 g of essential amino acids per kg of bodyweight is a better goal to shoot for. keep in mind, as well, the ACSM recommends only 14-15% of a strength trained athlete's calories come from protein.

 

[dswithers]

More important:
1. FAT MAKES YOU FAT. NOT TRUE: fat does not make you fat, excess calories make you fat, in fact, fats are required for essential body functions and dietary fat is generally way over maligned, read:



Synopsis for those in a hurry:

"Eat less saturated fat: that has been the take-home message from the U.S. government for the past 30 years. But while Americans have dutifully reduced the percentage of daily calories from saturated fat since 1970, the obesity rate during that time has more than doubled, diabetes has tripled, and heart disease is still the country’s biggest killer. Now a spate of new research, including a meta-analysis of nearly two dozen studies, suggests a reason why: investigators may have picked the wrong culprit."

2. All carbs are the same. NOT TRUE: carbs have widely differring absobtion and digestion levels (glycemic index) and continuing to quote from the above article:

"Processed carbohydrates, which many Americans eat today in place of fat, may increase the risk of obesity, diabetes and heart disease more than fat does...The finding joins other conclusions of the past few years that run counter to the conventional wisdom that saturated fat is bad for the heart because it increases total cholesterol levels. That idea is “based in large measure on extrapolations, which are not supported by the data,”

3. Cholesterol is bad and all possible methods should be used to reduce it, even those which may have bad side effects since high cholesterol is worse than any possible side effects: continnuing to quote from the above article:

"One problem with the old logic is that “total cholesterol is not a great predictor of risk,” says Meir Stampfer, a professor of nutrition and epidemiology at the Harvard School of Public Health. Although saturated fat boosts blood levels of “bad” LDL cholesterol, it also increases “good” HDL cholesterol. In 2008 Stampfer co-authored a study in the New England Journal of Medicine that followed 322 moderately obese individuals for two years as they adopted one of three diets: a low-fat, calorie-restricted diet based on American Heart Association guidelines; a Mediterranean, restricted-calorie diet rich in vegetables and low in red meat; and a low-carbohydrate, nonrestricted-calorie diet. Although the subjects on the low-carb diet ate the most saturated fat, they ended up with the healthiest ratio of HDL to LDL cholesterol and lost twice as much weight as their low-fat-eating counterparts."

 

[Karky]

My top 3 nutrition myths. These are for natural lifters. If you are not natural, different rules may apply. Feel free to add your own!
1. Cutting carbs will make you lose fat. NOT TRUE. Cutting calories will. Since carbs and protein have the same number of calories per gram (4), cutting 100 grams of carbs from your diet and replacing them with 100 grams of protein will lead to ZERO pounds lost. What it will lead to is poor memory, immune function, endocrine function and metabolic function, as carbs are needed to power these systems.

2. You need 1-1.5 grams of protein to build or retain muscle. NOT TRUE! Studies indicate that lean muscle can be added with as little as 1 gram per kg of lean body weight and that above 0.8 grams per pound of body weight is unnecessary. Simply put, more than a gram of protein will provide no better results, but may be stored as fat, as any extra calories may be that aren't utilized.

3. You can only absorb XXX grams of protein in one sitting. Again, NOT TRUE. But what you can absorb and what you need (especially post-workout) are totally different. At least one study found that more than 20 grams of protein PWO was completely unnecessary. The same study showed that there was no difference to muscle tissue repair or hormone levels between 20 g and 40 g. From AmJClinNutr. 2009 Jan; 89(1):161-8: "Ingestion of 20 g of intact protein is sufficient to maximally stimulate MPS (response of muscle) and APS (albumin protein synthesis) after resistance exercise." Another article recommends that protein consumption is irrelevant and that supplentation of 0.1 g of essential amino acids per kg of bodyweight is a better goal to shoot for. keep in mind, as well, the ACSM recommends only 14-15% of a strength trained athlete's calories come from protein.

About 1:
Protein has a higher thermic effect of feeding than carbs, so replacing 100g of carbs with 100g of protein should lead to some weight loss (assuming you were in calorie balance before). Won't be much, though.

I'd also like to see references on the claims that cutting carbs will lead to poor "... immune function, endocrine function and metabolic function"

 

[IWalkAlone]

About 1:
Protein has a higher thermic effect of feeding than carbs, so replacing 100g of carbs with 100g of protein should lead to some weight loss (assuming you were in calorie balance before). Won't be much, though.

I'd also like to see references on the claims that cutting carbs will lead to poor "... immune function, endocrine function and metabolic function"

That's really splitting hairs, but I guess I could have been more clear; I was referencing people who think they will lose weight simply by dropping carbs and replacing them with massive amounts of protein with no regard to total calories. Regarding the effect of carb depletion- what so you suppose your body runs on? Carbs play a role in each of those systems (yes even endocrine despite fat getting most of the credit), but I will have to link you to references when I get home-currently at work.

 

[Karky]

That's really splitting hairs, but I guess I could have been more clear; I was referencing people who think they will lose weight simply by dropping carbs and replacing them with massive amounts of protein with no regard to total calories. Regarding the effect of carb depletion- what so you suppose your body runs on? Carbs play a role in each of those systems (yes even endocrine despite fat getting most of the credit), but I will have to link you to references when I get home-currently at work.

Yeah, I agree it's splitting hairs, I just like to point it out every now and then. I'm a proponent of high protein diets for the thermic effect and hunger suppression they give.

If the body isn't getting any carbs it runs on:
Fatty acids, ketones and glucose made from gluconeogenesis.
The body is pretty good at switching from carbs to fat and ketones when you lower carbs drastically. I have seen a study on some cognitive measures that were suppressed a bit on a low carb diet, but nothing on the other systems you mentioned. I'm really interested in anything that has to do with low carb diets, so I'd really like to see studies on those systems.

 

[IWalkAlone]

OK, sorry it took so long to get back. I can't link sites from my Blackberry. Anyway, regarding immune function, at least one study noted "athletes who fail to include enough carbohydrate in their overall diets suffer from larger increases in blood levels of immune-system-suppressing 'stress hormones', and they experience increased perturbations in various indices of immune-system function, compared with athletes following a carbohydrate-rich diet" ('Elite Athlete Immunology: Importance of Nutrition', International Journal of Sports Medicine, Vol. 21 Supplement 1, pp. S44-S50, 2000). ANother pointed out that, "As it turns out, glucose (a six-carbon carbohydrate which is so prevalent in the blood that it is often called 'blood sugar') is an extremely important fuel for immune-system cells, including specialised white-blood cells called lymphocytes, neutrophils, and macrophages. Test-tube studies reveal that increases in white-blood-cell numbers are totally dependent on glucose concentrations; if glucose levels are low, white cells multiply at very modest rates" ('Role and Regulation of Glucose in Proliferating Cells', JNCI, Vol. 62, pp. 3-8, 197). Finally, two other studies have shown that "within-workout carbohydrate consumption prevents the commonly observed, exercise-induced fall in neutrophil function. It also helps maintain T-lymphocyte proliferation after a workout is over: in a study again involving 30 well-trained marathon runners, the placebo group exhibited a 45% decrease in T-cell function immediately after a long run, whereas the carbohydrate group experienced no such shortfall." ('The Effects of Carbohydrate Supplementation on Neutrophil Degranulation Responses to Prolonged Cycling', International Journal of Sports Medicine, Vol. 21, p. S73, 2000 AND 'Carbohydrate Supplementation and the Lymphocyte Proliferative Response to Long Endurance Running', International Journal of Sports Medicine, Vol. 19, pp. 574-580, 1998).
Regarding endocrine function, this study-'Carbohydrate and the Cytokine Response to 2.5 H of Running', Journal of Applied Physiology, Vol. 82, pp. 1662-1667, 1997- was pretty conclusive in its evidence that "there was a direct, inverse relationship between plasma cortisol concentrations and blood glucose: the higher the glucose level, the lower the cortisol. " I'm going to presume with your clear background in bio and physiology that I don't need to explain or post up studies regarding the role of carbs in metabolic function?

 

[Karky]

"athletes who fail to include enough carbohydrate in their overall diets suffer from larger increases in blood levels of immune-system-suppressing 'stress hormones', and they experience increased perturbations in various indices of immune-system function, compared with athletes following a carbohydrate-rich diet" ('Elite Athlete Immunology: Importance of Nutrition', International Journal of Sports Medicine, Vol. 21 Supplement 1, pp. S44-S50, 2000)

This is interesting. Too bad I can't access the full text. Do you know if "fail to include enough carbohydrate in their overall diets" means a ketogenic diet or just a diet too low in carbs but not low enough to go into ketosis?

ANother pointed out that, "As it turns out, glucose (a six-carbon carbohydrate which is so prevalent in the blood that it is often called 'blood sugar') is an extremely important fuel for immune-system cells, including specialised white-blood cells called lymphocytes, neutrophils, and macrophages. Test-tube studies reveal that increases in white-blood-cell numbers are totally dependent on glucose concentrations; if glucose levels are low, white cells multiply at very modest rates"

Can't find the full text to this one. What levels of glucose did they use? blood glucose doesn't go that low during a ketogenic diet.

The ones on immune function response after exercise (the open window) looks interesting. Unfortunately, I don't have access to the international journal of sports medicine.

I was aware of the decrease in cortisol, don't think I'd call it "poor endocrine function" though.

A lot of people on ketogenic diets consume glucose during exercise, though. It seems they can do that without going out of ketosis.

 

[IWalkAlone]

Will have to link them when I get home for further details. I may be wrong on this one, but regarding cortisol and endocrine function, it seems like I have read somewhere that carbs play a significant role in adrenal fatigue, but I'm not remembering if the studies advised upping or lowering carbs. Either way, they do affect adrenal function. I'll post more on this when I'm at a PC. At any rate, I stand by my original post that carbs are not the enemy, reducing them without significant reduction in total calories will not lead to substantial body fat loss, and the general rule of thumb for athletes is 50-60% of your calories should be from carbs. Interesting that someone mentioned the Glycmic index- the most referred to and most misunderstood weight loss tool. It was developed to measure blood glucose levels in diabetics, not insulin response based on consumption after fasting. But how good is it? The two things people should know- first, the American Diabetes Association does not endorse it because (second fact) it is flawed in its very nature- ice cream is considered a low glycemic food LOL. One last thing regarding carbs- a 2003 study published in the journal Diabetes, found that over an 8 week period, obese adults following a high-fat, low carb diet (20%/60%) and a group following a high-fat, low carb diet (60%/20%) had no difference in weight loss whatsoever. Granted, the study did not take into account the effects of protein, but it does lend credit to the idea that cutting carbs blindly does not equate to bf loss.

 

[Karky]

Yeah, I agree that cutting carbs does not equal weight loss, the only way to do that is to cut calories (whether you do that by cutting carbs, protein, fat or a combination). I'm just interested in the effects of a low carb diet on the body.

As far as carb supplementation and immune function after exercise goes, those studies used carbs during exercise and doesn't prove much outside of that (IE, resting conditions). Also, I found a meta analysis from 2007 claiming that supplementing carbs during exercise doesn't help the exercise induced transient immunodepression:

However, they didn't look at neutrophil degranulation. But only one of the trials they included found that CHO helped with lymphocyte proliferation response.

 

[Karky]

Just found this:
Exercise, nutrition and immune function


The link is a free full text.

Talks about interferon depression being absent with carbohydrate ingestion during exercise (the meta analysis referenced to before did not include this outcome)

They also write this:

While carbohydrate feeding during exercise appears
to be effective in minimizing some of the immune
perturbations associated with prolonged continuous
strenuous exercise, it appears less effective for less
demanding exercise of an intermittent nature, for
example football (Bishop et al., 1999b) or rowing
(Nieman et al., 1999) training. It is also apparent that
carbohydrate feeding is not as effective in reducing
immune cell trafficking and functional depression when
continuous prolonged exercise is performed to the point
of fatigue (Bishop et al., 2001a)

Makes me wonder how the studies that found carbs helped the depression were conducted. Carbs increase the time to fatigue, and if the exercise was done at the same relative intensity with the same duration for all subjects, the effect could simply be that it takes longer to perturb homeostasis with increased carbohydrates, and not an effect of carbs as fuel for the immune system.

EDIT: just looked at the study that found carbs helped with interferon levels. they exercised for 2.5 hours at 54% of Wmax. Not to exhaustion or anything like that. Those who consumed carbs would likely have to exercise longer or harder than the placebo group to experience a similar disturbance in homeostasis from the exercise.

 

[IWalkAlone]

While I am not debating your POV, I think perhaps you are missing the point of my initial post. It was not meant to start any sort of discussion about cortisol, exercise induced immunodeficiency or anything of that nature. It was directed to the people who incorrectly believe they will somehow lose body fat by cutting out their carbs. Between the Atkins craze and the media in America, there are far too many people who believe this to be true. That was the point I was making.The average person- and reader of most forums- doesn't care nearly as much as you or me about the body of scientific literature (which seems to have studies that could support either of our sides); they often care only about what is going to help them reach their goals.

 

[Karky]

Yeah, and I agree with you on that. I get that the initial point was just about weight loss and not all of this stuff I've forced the discussion into

I should really have started a new thread for the carb supplementation and immunodepression after exercise discussion. I just sort of went with it when you cited those studies.. I started pubmeding, and when I do that, I can't be stopped

 

[Karky]

The difference between me and a dog:
When you play fetch with a dog, you use a stick. When you play fetch with Karky, you use a ketostick



Dunno who I'm so into keto diets and carb supps during exercise.. I don't even do keto diets or think they are particularly fabulous.

 

[IWalkAlone]

Lol all good. This forum looks like the kind of place I enjoy- generally intelligent, well-educated POV with very little bro-science.

 

[sexanoe]

I'm doing a low carb cut. My weight loss rate is not really an issue, but losing fat and keeping muscle is very important. Is replacing 400 calories total of brown rice in my lunch and dinner meals with more protein (chicken breast and salmon) going to be much of a factor? The only other "starchy" carbs I'm eating is a serving of oatmeal in the morning. The rest is pretty much from veggies (no fruit besides a serving of strawberries).