Lean Times

While John Cloud erred in several ways in his Time magazine article titled Why Exercise Won’t Make You Thin, he's correct on the fat loss issue. Many people including the Surgeon General have lambasted Mr. Cloud for his candor and scientifically sound information on getting svelte.

 What he was saying is that exercise does not affect fat loss much if at all. And research on the subject of exercise and fat loss supports his statement time and time again. Even the American College of Sports Medicine agrees that exercise does little to affect it as we’ll learn shortly.

 The knee-jerk reactions that bombarded the internet lambasting Cloud for the article which include Jake Steinfeld (the Jake of  Body by Jake Fame) only serve to keep people fat and injured.  They assume that Cloud is saying that exercise is not good for us or that it provides no benefit. That is not what John Cloud was saying. And he does, in fact, make mention of the many benefits of exercise. In fact he even says at the end of the article “You should exercise to improve your health…” Again, the title of the article is "Why Exercise Won't Make You Thin." And it won't. It never has and that is a fact of science. Good for John for having the guts to reveal this information and help us all get closer to the truth and, perhaps, save us from an orthopedic injury.

 Jake Steinfield, who may I say I respect and admire, had this to say on his Huffington Post blog:

 “Cloud states that the American College of Sports Medicine and the American Heart Association's guidelines regarding weight loss and exercise are unrealistic, especially for those with jobs or those looking for jobs. The guidelines encourage exercise for 60 to 90 minutes on most days of the week. What he fails to mention is that they also say that "research shows that moderate-intensity physical activity can be accumulated throughout the day in 10-minute bouts, which can be just as effective as exercising for 30 minutes straight. This can be useful when trying to fit physical activity into a busy schedule."

 What Jake neglects to mention is that, unfortunately for those who seek to lose weight via exercise, the ACSM admits exercise doesn’t work. From the AHA/ ACSM paper titled: Physical Activity and Public Health. Updated Recommendation for Adults From the American College of Sports Medicine and the American Heart Association (page 7):

 “It is reasonable to assume that persons with relatively high daily energy expenditures would be less likely to gain weight over time, compared with those who have low energy expenditures. So far, data to support this hypothesis are not particularly compelling.”

 Also from Jake’s Huff Post blog (he is quoting Dr. Robert Sallis, past president of the American College of Sports Medicine): 

"If exercise were a pharmaceutical it would be the most potent drug ever invented. Exercise has been clearly proven to prevent and treat chronic diseases and lower mortality rates. From a scientific perspective, any attempt to discredit the value of exercise is just laughable and potentially very harmful to the public. As a physician who works hard to get patients more active, I find it very irresponsible for Time magazine to run a story that so misrepresents the facts."

Well, Dr. Sallis isn’t quite correct. All of the studies done on exercise that are used as iron clad proof that exercise prevents and treats chronic disease and lowers mortality rates are epidemiological / observational studies. These types of studies are not controlled research studies. They can only suggest an association - they do not prove cause and effect. Just because people who exercise regulary live longer and are generally healthier than those who don’t doesn’t mean that the exercise caused these benefits.

But why? Why does exercise have little to no effect on fat loss? There are many reasons including increased appetite and being more sedentary after the workout. An interesting example of this was watching my daughters ride their bikes around Mackinac Island last week while we were on vacation and after the 8 mile ride all they wanted to do was sit in bed and read.

But the most important issue is the understanding of the language of fat loss. What tells the body to release fat from the fat cells?

Fat loss is not a numbers game. In other words, a calorie is not always just a calorie. Fat loss is a hormonal game. Fat is not released from the fat cells because you burn calories doing exercise. No one loses fat without altering their diet and sticking to that alteration. And the specific alteration is a reduction in carbohydrates, not necessarily calories, which in turn reduces insulin secretion, which in turn allows the lipids to be released form the fat cell. That's the biochemistry. We don't get to vote on it. There are other issues, but this is far and away the most critical.

And why do so many experts and the ACSM assume exercise will work even though time and time again research fails to support the assumption. So too do the failures of millions of Americans who try to shed the pounds by sweating to the oldies.

A thorough read of Gary Taubes' book Good Calories Bad Calories explains this in great detail. According to Gary:

"Obesity is a disorder of excess fat accumulation. So the question everyone should be asking and always should have been asking is what factors regulate fat accumulation? As it turns out we've known that since the 1960s and it is not controversial. You can find it in endocrinology and biochemistry textbooks, just not in obesity textbooks. Fat accumulation is fundamentally determined by the hormone insulin and our insulin levels go up and down with the quantity and quality of carbohydrates we consume. The more carbs we eat, the more refined they are and the sweeter they are (the more fructose in them, in other words), the more insulin we will ultimately secrete. The higher our insulin levels, the more fat we accumulate."

Exercise cannot and does not solve the problem of fat release from the fat cell. The real key to the fat cell is not exercise. It is the control of hormonal tone and the most important hormone to control is insulin.

As the late Carl Sagan said: "Science as a candle in the dark."

Comments

[John]

Fred,

Thanks for this blog post and thank you also for allowing the debate in the comments section.

As someone who's actually read GCBC (more than once), I can attest to the honesty of Gary Taubes as an author. He makes clear that the "carbohydrate hypothesis" is just that, a _hypothesis_. However, it is a hypothesis much better supported by the data than the lipid hypothesis or the "caloric intake" hypothesis. GCBC is, more than anything, a call for studies designed to test the carbohydrate hypothesis.

For those who've read GCBC, they will find reference to several (if not many) societies in places like Africa and Jamaica (among others) in which undernutrition in children and obesity (particularly in women over 30) _coexist_. If one sticks to the "caloric intake" hypothesis of obesity, one would be forced to conclude that obese mothers are withholding food from their undernourished children so that they could become obese, a conclusion that is clearly absurd.

This does not say, of course, that calories don't matter. It simply makes clear that much more is going on than just caloric consumption. Taubes lists many studies in the bibliography of GCBC that conclude that weight loss from caloric restriction is much smaller than would be expected and much smaller than the weight loss obtained from carbohydrate restriction. One could argue that more research needs to be done and, in fact, that is what Taubes is arguing in GCBC.

[fred hahn]

"On the studies you cited - a few things.First, let me say that I am not against low carb at all. For many people, low carb works best as a means of fat loss. I do prescribe lower carb approaches for many of my clients."

Who would you NOT prescribe it for? I assume you mean your fat loss clients? Thos who do not need to lose fat can get away with a modest carb intake so long as it is from fruits and vegetables. Grains as I'm sure you must know have no place in the human diet. See Cordain's paper 'Cereal Grains - Humanity's Double Edged Sword' for starters.

"I do have to comment on a general folly that many low carb advocates fall for. When comparing low carb and low fat diets, you are more than likely comparing moderately low and moderately high protein. That is the difference maker."

No. There are many studies that compare low fat to low carb and keep protein virtually equal. The two studies I cited had protein for low fat and low carb at 20% and 28% respectively. If you want to argue that the 8% protein made all the difference in the benefits that the low carb group received over the low fat, you'd have to come up with a VERY good reason for that.

"Read the research of Laymen - doubling the RDA for protein is associated with better satiety and hence better weight loss, fat loss and improvements in health markers."

Yes. I know his work. After doubling the protein you are also lowering the carbs, correct? This has nothing to do with the studies I cited.

"To wit, the first study you cited (Volek) protein levels were 20% for the low fat and 28% for the low carb. Also, this is not a metabolic ward study where their activity levels are tracked, etc."

So what are you suggesting? That the all the folks in the VLC group snuck exercise into the fray and all the LF subjects did not? You're graspinf at straws to not see the benefits of LC over LF.

"Also, 12 weeks is quite short - there are acute weight variances in differing macronutrient compositions (water loss with low carb) but they tend to even out in the long run."

12 weeks is short? Another grasp at straws. How long must the study be for you to deem it long enough? I could say the same in opposition to the studies you cited that supposedly indicate that exercise has no effect on hunfer right?
And they only "even out" when the LC subjects increase their carbs as they did in the A to Z study just to name one.

"Bottom line, when adequate protein levels are established (moderately high) and EFA's are adequate, how you shuffle around the carbs and fat level doesn't make much of a difference."

Show me a study that supports this claim.

"If you disagree show me studies that show statistically significant differences in fat loss when protein levels are equal and adequate."

I did already citing the Volek studies. The RDA for protein is between 10% and 35%. Given this, Volek doubles the RDA.

Remember, you stated that Donald Laymen showed that when the USDA for protein is doubled, better fat loss outcomes occur. But when they ARE doubled, carbohydrate is also reduced. So you can't say that the superior fat loss is solely due to the increased protein now can you especially when biochem tells us that it is low circulating insulin that allows for fat to be released from the fat cell. (You must have missed that part in Gary's book.)

Here is a direct quote from the Fifth edition (2009) of Lehninger Principles of Biochemistry (which is probably the most respected biochemistry textbook in the business):

"High blood glucose elicits the release of insulin, which speeds the uptake of glucose by tissues and favors the storage of fuels as glycogen and triaglycerols, while inhibiting fatty acid mobilization in adipose tissue."

Do you disagree with this?

[Mike]

It's been a great discussion - here's what I propose.

The format of this blog isn't very conducive for quoting, posting links and such. I propose we move the debate to the JP Fitness Forums. http://forums.jpfitness.com/

It would also be interesting to get a wide variety of opinions from professionals in the industry. The forum is mostly fitness professionals such as you and I and also has a fair number of contibutors who are low carb advocates (Cassandra Forsythe, Adam Campbell). It's easy to register.

This is a great opportunity for you to bring some of your ideas to the table.

I'll start a thread now and feel free to jump in if you want.

[Mike]

Again Fred - nice spin.

You talked in circles without so much as citing one scientific study.

I AM biased. I am biased towards good science and the totality of evidence. I am biased towards the idea of individual variances and I am biased against nutritional single-mindedness and one superior method. Note that this is not the same as being prejudice - which is what you and others appear to have against anyone who dares question the wisdom of Gary Taubes (and again, Fred - did read the book).

Again, I'm not against low carb, but it's a convenient argument to suggest that we should credit the carbs when we lower calories and achieve fat loss.

I will reiterate: When protein is sufficient (moderately high) and EFA's are adequate, carb/fat level make very little difference. Almost all studies that show superiority of low carb over low fat are actually comparing low protein to high protein. If you disagree, kindly present papers that disagree with this.

Regarding insulin: Under certain (mostly transient) conditions, insulin CAN suppress fatty acid oxidation temporarily - however under scientific scrutiny, these effects do not develop into macro-effects in hypocaloric conditions.

Energy restriction improves glycemic control, regardless of a wide range of carb proportions from 15-73% (Freedman, Obes. Res. March 2001.)

Under hypocaloric conditions, the most hyperinsulinemenic and insulin resistant lost weight as effectively as the most insulin sensitive. (Mcglaughlin et al. J. of clin endocrinol metab. feb, 2009)

Another recent trial confirmed these results when looking at normal vs. impaired glucose metabolism, insulin response had no effect on weight or fat loss (de Luis. Clin Nutr Feb. 2006)

(Noakes et. al nutr metab. jan 2006) found no difference in weight loss in 3 different diets ranging from 4 - 70% carbohydrate. This despite a 33% decrease in fasting insulin levels of the lowest carb group.

In overfeeding subjects, there doesn't seem to be a significant difference in where the calories come from either;

Lammert O, Grunnet N, Faber P, Bjørnsbo KS, Dich J, Larsen LO, Neese RA,
Hellerstein MK, Quistorff B.
Effects of isoenergetic overfeeding of either carbohydrate or fat in young men.
Br J Nutr. 2000 Aug;84(2):233-45.

McDevitt RM, Poppitt SD, Murgatroyd PR, Prentice AM.
Macronutrient disposal during controlled overfeeding with glucose, fructose,
sucrose, or fat in lean and obese women.
Am J Clin Nutr. 2000 Aug;72(2):369-77.

Horton TJ, Drougas H, Brachey A, Reed GW, Peters JC, Hill JO.
Fat and carbohydrate overfeeding in humans: different effects on energy storage.
Am J Clin Nutr. 1995 Jul;62(1):19-29.

With these and other studies, it is clearly misguided to label insulin as THE factor in fat gain/loss.

[fred hahn]

Nadine -

You're very welcome and good for you to have the guts to release yourself from the paralysis of the 'calorie is a calorie / exercise a lot' to lose fat paradigm. A paradigm that people like Mike, James and Ricardo are still mired in. You, like many others, have discovered that obeying biochemistry is the only way to lose fat and gain muscle.

People like Mike are painfully unaware or should I say innocently ignorant of these facts. They berate Gary Taubes without ever reading his book and come on this blog and try and prove me wrong which only serves to make them look ever more uneducated since what I am saying is grounded in science. They just don't want to believe what's directly in front of their faces. They can't give up their biases for whatever reason. They won't read the studies thoroughly and can't even think deeply enough to realize that yhe notion they espouse that you can reduce appetite by increasing energy expenditure is ludicrous. Any organism that evolved to eat less in response to increased activity would become extinct in short order.

Ah well...In fact I have several papers where researchers compared groups of exercisers/dieters to dieters alone and the weight lost was no different. Problem is, I cannot locate them as they were not in electronic format and many of my hard copy papers are not with me at present. I will try to locate these soon for a good blog on the subject.

Of course when I present the blog, folks like Mike will say "Well this proves nothing. The group that exercised didn't lose more weight because they didn't stick to their diet and ate more as it was not a ward study and diet could not really be controlled." Of course, I will reply "Ate more???"

Here's one point they never consider:

Let's say you lower your calories from 2000 a day to 1200 to lose weight. Without a doubt when people go on a lower calorie diet, they significantly lower their intake of fructose, HF corn syrup, trans fats, hydrogenated fats, and by lowering their total calories, they lower their total carb intake.

After 3 months they have lost 10 pounds! Yippee! See what the lower calories did for me! Not so fast rabbit. That conclusion would be bad science. We actually can't say what single element did the trick or if it was a combination of all of them.

But if we look to our biochem texts some truths are revealed.

Even if calorie intake is below BMR, if insulin levels are high and especially if a person has become insulin insensitive which forces the body to produce ever more insulin to deal with the same amount of blood sugar (and this only gets worse over time if carbs keep getting stuffed into the body), excess fat can indeed be shunted into the fat cells. The 2nd law of thermodynamics supports this.

The converse is true also.

So Mike, Ricardo and James can keep talking their 'a calorie is a calorie' talk and keep insisting that exercise doesn't increase energy intake but in the end, it's all beside the point.

If you want to lose fat you have to explain this to your body on a biochemical level. Fat is released from the fat cell when insulin levels are low. When they are high, the fat in the fat cell is going nowhere. Not my opinion - it's fact.

[slow burn nadine]

well i'm not going to join this scientific fray.

i am just going to mention the many many overweight women i see going for a daily walk/jog who remain overweight.
and why don't overweight people take part in sport? they have fun poked at them - they are made to feel horrible - of course they don't parade themselves in skimpy sport gear!!
you don't know what it's like to be overweight.
some people may lose weight by any method perhaps, but there is a section of overweight people who only manage to lose weight by restricting carbs. why do some people gain just a few pounds and others pile them on?? eating the same food. have you ever seen a thin person eating loads of food, not exercising and not gaining an ounce?
i've counted calories, reduced fat and yes exercised aeobically - it did not work.
lo carb is producing results. cutting OUT (not down) grains, has made cravings disappear. slow burn has increased my muscles. i have lost almost a stone in weight.
thanks Fred.

[Mike]

Regarding GCBC? Yup, did read the book. It's funny how the low carb brigade just assumes that anyone who reads the book will automatically follow it blindly. Here's a quick-and-dirty review.

Very thorough and historically-detailed accounts on dietary recommendations and how they are influenced. One of the best books I've read in this regard.

Slamming the lipid hypothesis - again, puts many nails in that coffin.

Carbohydrate hypothesis? Pretty weak - cherry picks studies in this regard and ignores the one's that don't align with his ideals.

Exercise theory? Read carbohydrate hypothesis.

[Mike]

Fred,

On the studies you cited - a few things.

First, let me say that I am not against low carb at all. For many people, low carb works best as a means of fat loss. I do prescribe lower carb approaches for many of my clients.

I do have to comment on a general folly that many low carb advocates fall for. When comparing low carb and low fat diets, you are more than likely comparing moderately low and moderately high protein. That is the difference maker. Read the research of Laymen - doubling the RDA for protein is associated with better satiety and hence better weight loss, fat loss and improvements in health markers.

To wit, the first study you cited (Volek) protein levels were 20% for the low fat and 28% for the low carb. Also, this is not a metabolic ward study where their activity levels are tracked, etc. Also, 12 weeks is quite short - there are acute weight variances in differing macronutrient compositions (water loss with low carb) but they tend to even out in the long run.

Bottom line, when adequate protein levels are established (moderately high) and EFA's are adequate, how you shuffle around the carbs and fat level doesn't make much of a difference. If you disagree show me studies that show statistically significant differences in fat loss when protein levels are equal and adequate.

[Mike]

Some more quick hits...

John - nice anectdote. Perhaps the person training for the marathon ate more. You have no idea whether this is correlation or causation. It's useless.

Mr Freddy - your comments highlight your ignorance. I'm not suggesting you are not intelligent - just unaware. McDonald, Aragon, Hale, Peele, etc. are not advocates of low fat. I know its convenient for the extreme low carbers to categorize all who aren't on board with their fanatasims of being "low fat", but we actually review all sides of the story.

McDonald as an example wrote a book called "The Ketogenic Diet". Low fat, huh? McDonald gets criticism from both the low fat and high fat groups equally. He is smart enough to stay away from the fringe nutritional BS and presribe dietary plans according to individual need - and yes - some people do actually thrive better on a higher carb diet.

[Mike]

Lot of different tangents - I'll start with the exercise/hunger one - again.

Once again, the King paper I linked to examined every study relating to exercise and hunger and he drew the following conclusion;

"The relationship between exercise-induced energy deficits and food consumption has been subjected to much scrutiny, and
the evidence suggests that there is no increase in hunger or energy intake as a result of an exercise-induced energy
deficit (Reger et al. 1986; Reger & Alison, 1987; Thompson et al. 1988; Kissileff et al. 1990; King et al. 1994; King & Blundell, 1995)"

So please, Fred if you insist that the evidence for exercise causing hunger and subsequent overeating is equal, please site some comparable studies of equal or greater design to prove so.

OF COURSE the results of studies produce varying results, but studies draw conclusions on statistical significance. If the results showed even close to as many people overeating in response to exercise, the authors would conclude that the results were decidedly inconclusive. This is not the case as I've already outlined.

Please stop trying to grasp at straws and pinpoint possible methodological flaws unless you have proof of such. No study is perfect, however repeated trials on the subject are showing similar results time after time.

[fred hahn]

"Dear Fred, weight loss is loosing any type of weight, either lean or fat. Loosing fat is the main objective, of course. But it is reasonable to also accept some lean mass loss, as the body won't have to carry so much extra weight..."

Hi Ricardo - this is only true of the morbidly obese.

"Exercising your muscles will send them the message that they are necessary and so their lean mass must be preserved or even increased."

Only if the exercise is resistance training.

"Our ancestors had a high level of energy expenditure, they exercised a lot, they walked kilometers every day and they didn't have easy access to food."

Where is your evidence to support this statement? Some may have, others did not.

"The more they wanted to eat, the more energy they had to expend. In other words, they weren't sedentary as us, they exercised/walked frequently, and so weren't fat."

You speculate. I contend they weren't fat because the foods they ate were high in fat and protein and low in carbohydrate. If what you say is true, they would keep losing weight and losing weight and this this not happen. You need to read some basic biochem texts.

"I must agree when you say "there are plenty of active, fat people and plenty of sedentary lean people", but certainly most active people are thin and most sedentary is fat."

Even if true, this doesn't prove that activity = leanness. You're not thinking deeply enough nor are you paying attention to basic biochemistry.

"I was referring to runners (chronic cardio), you generally don't see overweight people in 10K or Hal-Marathon races, and their diets are no different from the average typical diet."

That is definitley not true. Athletes almost always shun junk foods, sodas, etc. and instead eat nutrient dense foods. They also sleep better. They also....

"This is not epidemiology because the energetic balance that leads to weight loss is well understood, except by Taubes - create a calorie deficit, by eating less and exercising more, and you'll loose weight."

Eating less yes, exercising more no. Did you read Taubes' book? Doesn't sound like it.

Doesn't matter if your diet is ketogenic, high-carb or MacDonalds. Isocaloric metabolic wards don't prove any advantage of varying macro-nutrients, but of course low-carb provides better/easier appetite control."

Yes but that is not the only reason. I listed 2 studies above that show that in isocaloric diets, low carb results in greater fat loss.

"You say that "No one ever lost an ounce by exercising and not altering their diet" so how do you explain the case of several professional athletes that end their careers, when they are 30 or 40 years old, and immediately start putting weight?"

They are rich and they eat more. It's called 'continued occupation.' There are also fat professional athletes and lean pros who have quit their careers.

"They certainly don't alter their diets much and at the same time, because they stopped their intense activity, are no longer able to maintain an isocaloric condition. So they start gaining weight."

You are just making stuff up here Ricardo.

"If these post-modern exercise ideas were correct, as they stopped exercise they would immediately loose all their appetite, and perhaps even start loosing weight, isn't it? But the contrary occurs much more frequently. I don't know how many studies there about or related to weight loss, probably 1 million? Certainly not a single one of them escaped this simple law of nature, which is: weight loss occurs only if a calorie deficit is created, and you can achieve this with diet (eat less), exercise (exercise more) or preferably both approaches."

Like I said, show me one study that shows that exercise alone significantly decreases body fat. It should be easy to find one, no?

[Ricardo]

Dear Fred, weight loss is loosing any type of weight, either lean or fat. Loosing fat is the main objective, of course. But it is reasonable to also accept some lean mass loss, as the body won't have to carry so much extra weight. Exercising your muscles will send them the message that they are necessary and so their lean mass must be preserved or even increased. Our ancestors had a high level of energy expenditure, they exercised a lot, they walked kilometers every day and they didn't have easy access to food. The more they wanted to eat, the more energy they had to expend. In other words, they weren't sedentary as us, they exercised/walked frequently, and so weren't fat. I must agree when you say "there are plenty of active, fat people and plenty of sedentary lean people", but certainly most active people are thin and most sedentary is fat. I was referring to runners (chronic cardio), you generally don't see overweight people in 10K or Hal-Marathon races, and their diets are no different from the average typical diet. This is not epidemiology because the energetic balance that leads to weight loss is well understood, except by Taubes - create a calorie deficit, by eating less and exercising more, and you'll loose weight. Doesn't matter if your diet is ketogenic, high-carb or MacDonalds. Isocaloric metabolic wards don't prove any advantage of varying macro-nutrients, but of course low-carb provides better/easier appetite control. You say that "No one ever lost an ounce by exercising and not altering their diet" so how do you explain the case of several professional athletes that end their careers, when they are 30 or 40 years old, and immediately start putting weight? They certainly don't alter their diets much and at the same time, because they stopped their intense activity, are no longer able to maintain an isocaloric condition. So they start gaining weight. If these post-modern exercise ideas were correct, as they stopped exercise they would immediately loose all their appetite, and perhaps even start loosing weight, isn't it? But the contrary occurs much more frequently. I don't know how many studies there about or related to weight loss, probably 1 million? Certainly not a single one of them escaped this simple law of nature, which is: weight loss occurs only if a calorie deficit is created, and you can achieve this with diet (eat less), exercise (exercise more) or preferably both approaches.

[mrfreddy]

just want to add something about all those metabolic ward studies that AC uses to prop us his arguments... all they prove is that people on very low calorie diets will lose weight, regardless of the carb/protein/fat ratios. The metabolic advantage, if it exists, kicks in when people eat the levels of calories people normally eat.

what I wonder is, why are all these anti MA folks so nasty? Hale, McDonaldy, etc. - they are all so foul tempered.. could it be their low fat diets are affecting their temperament and judgement? Sure looks that way.

[fred hahn]

"I have a long-term client that I have trained for more than 6 years. She decided that she would run the NYC Marathon. She has been upping her running time to currently 20 hours a week. She started running in April. She has only lost 3 pounds. She has told me that she has an increased appetite."

Hi John -

This 3 pounds can easily be water fluctuation as you know and yes, the increased appetite is common. My appetite increases after exercise but nor for some time. It is supressed for about an hour after but a few hours later I am ravenous. My workouts last 20-30 minutes. But the total time I spend exercising is only 15 minutes. How many calories can I possibly be burning?

[fred hahn]

Here's one:

Carbohydrate restriction has a more favorable impact on the metabolic syndrome than a low fat diet.
Volek JS, Phinney SD, Forsythe CE, Quann EE, Wood RJ, Puglisi MJ, Kraemer WJ, Bibus DM, Fernandez ML, Feinman RD.

Department of Kinesiology, University of Connecticut, 2095 Hillside Road, Storrs, CT 06269-1110, USA. jeff.volek@uconn.edu

We recently proposed that the biological markers improved by carbohydrate restriction were precisely those that define the metabolic syndrome (MetS), and that the common thread was regulation of insulin as a control element. We specifically tested the idea with a 12-week study comparing two hypocaloric diets (approximately 1,500 kcal): a carbohydrate-restricted diet (CRD) (%carbohydrate:fat:protein = 12:59:28) and a low-fat diet (LFD) (56:24:20) in 40 subjects with atherogenic dyslipidemia. Both interventions led to improvements in several metabolic markers, but subjects following the CRD had consistently reduced glucose (-12%) and insulin (-50%) concentrations, insulin sensitivity (-55%), weight loss (-10%), decreased adiposity (-14%), and more favorable triacylglycerol (TAG) (-51%), HDL-C (13%) and total cholesterol/HDL-C ratio (-14%) responses. In addition to these markers for MetS, the CRD subjects showed more favorable responses to alternative indicators of cardiovascular risk: postprandial lipemia (-47%), the Apo B/Apo A-1 ratio (-16%), and LDL particle distribution. Despite a threefold higher intake of dietary saturated fat during the CRD, saturated fatty acids in TAG and cholesteryl ester were significantly decreased, as was palmitoleic acid (16:1n-7), an endogenous marker of lipogenesis, compared to subjects consuming the LFD. Serum retinol binding protein 4 has been linked to insulin-resistant states, and only the CRD decreased this marker (-20%). The findings provide support for unifying the disparate markers of MetS and for the proposed intimate connection with dietary carbohydrate. The results support the use of dietary carbohydrate restriction as an effective approach to improve features of MetS and cardiovascular risk.

And another:

Comparison of Low Fat and Low Carbohydrate Diets
on Circulating Fatty Acid Composition and Markers
of Inflammation
Cassandra E. Forsythe Æ Stephen D. Phinney Æ Maria Luz Fernandez Æ
Erin E. Quann Æ Richard J. Wood Æ Doug M. Bibus Æ William J. Kraemer Æ
Richard D. Feinman Æ Jeff S. Volek
Received: 5 July 2007 / Revised: 24 October 2007 / Accepted: 25 October 2007 / Published online: 29 November 2007

In both calories were isocaloric and the low carb diets fared better in every aspect including weight loss.

Send me your email address and I'll email you the full text of the papers.

[Jophn Tatore]

I have a long-term client that I have trained for more than 6 years. She decided that she would run the NYC Marathon. She has been upping her running time to currently 20 hours a week. She started running in April. She has only lost 3 pounds. She has told me that she has an increased appetite.

[fred hahn]

"Fred, you continute to repeat speculation and potential flaws in the studies I present and don't present ones of your own."

There aren't any studies that I am aware of that conclusively state that exercising more = eating more in every individual across the board. I showed you that in the very studies you presented increases in energy intake occurso it's not speculation. I said that increased appetite after exercise was ONE factor - and it is.

"The whole "some people do, some people don't" get hungry you are spouting is only a half truth when it is more accurate to say "according to research, the vast majority of people DO NOT eat more in response to exercise." The latter is more accurate."

No that is inaccurate. Prove "vast majority." You have no evidence to support this claim. The truth is some people do, some don't. We don't know how many do or don't. That is the fact. And it is also a fact that exercise a lone does not effect fat loss much of at all. Not weight loss - fat loss.

"And Colpo's research is undeniable. You can say what you want about his personality but that doesn't change the facts - which are that you, Taubes, Eades or anyone else would be 20K richer if you could actually prove your metabolic advantage fallacy."

Colpo is right on some things but wrong, dead wrong on the MA issue. Seek out the research by Dr. Volek. Several studies from Jeff Volek’s lab show big differences in weight loss for subjects on isocaloric diets but with different macronutrient contents.

"Plus, Gary Taubes travels the world and lectures because he has generated a lot of publicity with his sensentionalist journalism. Some of the true gems - like the Colpo's, Aragon's, Hale's, McDonalds' work isn't provacative enough - it's just the truth based on what science has told us so far."

No it's because it isn't scientific or thorough enough and mostly quite poorly written. You haven't read Taubes' book have you?

"More on this later..."

Indeed....

[Mike]

Fred, you continute to repeat speculation and potential flaws in the studies I present and don't present ones of your own.

The whole "some people do, some people don't" get hungry you are spouting is only a half truth when it is more accurate to say "according to research, the vast majority of people DO NOT eat more in response to exercise." The latter is more accurate.

And Colpo's research is undeniable. You can say what you want about his personality but that doesn't change the facts - which are that you, Taubes, Eades or anyone else would be 20K richer if you could actually prove your metabolic advantage fallacy.

Plus, Gary Taubes travels the world and lectures because he has generated a lot of publicity with his sensentionalist journalism. Some of the true gems - like the Colpo's, Aragon's, Hale's, McDonalds' work isn't provacative enough - it's just the truth based on what science has told us so far.

More on this later...

I

[fred hahn]

Rick I'll intersperese my comments between yours:

"The idea that exercise doesn't help in weight loss has no scientific basis, as the other commenters already pointed out..."

OK. Find me one study that indicates that exercise alone causes significant fat loss. Just one. And bear in mind that if a person vigorously exercises and looses weight BUT the majority of that weight is lean tissue, this doesn't count.

"...and from an evolutionary perspective doesn't make sense."

I don't follow - evolutionary? Our paleolithic ancestors didn't exercise to lose fat and were more than likely never obese. They ate very little carbohydrates and zero junk food.

"Also, I wonder how people even believe these kind of myths. If exercise was irrelevant for weight loss, you would expect to see quite a few really fat individuals in wekend sport events..."

You mean like football linemen, baseball players, heavy weight weight lifters, world's strongest men contests, etc.?

"...at least as much as the percentage of sedentary people. But this is no the reality, most people who pratice some sport, don't have a car and have to walk to work, are generally thiner and healthier."

This has got nothing to do with why they are lean. There are plenty of active, fat people and plenty of sedentary lean people.

"...Perhaps this is just an epidemiological association?"

Correct!

"All very successful weight loss stories start with a couch potato guy turning of the TV, standing up and start walking 7 days/week, 1 hour/day. Forget about Taubes/Cloud fantasy ideas about exercise and please read some Anthony Colpo, starting from pages 74 to 77 from this document: http://www.thefatlossbible.net/They_Are_All_Mad.pdf"

These people also alter their diets. No one ever lost an ounce by exercising and not altering their diet.

Colpo is insane. His fat loss bible is a joke. He is a nasty, foul-mouthed child who thinks he's got the lock and key on everything health related. He doesn't even know what the 2nd law of thermodynamics is. I'd love to see a debate between Gary Taubes and Colpo. Colpo would be decimated.

If Colpo is so smart, where is he? How come he is not lecturing the world over as Gary is?

[fred hahn]

James -

If you look at the many studies that deal with exercise and hunger some do show that some people do increase energy intake. Some don't. And that is what I said - it is a factor.

The reason why exercising people seem to keep weight off better is the added muscle. I saw your post on Drew Baye's site and you misunderstand the role of muscle and RMR. The added muscle accounts for some of the increase but trained muscle - not just the added muscle - has a higher MR. Dr. Wayne Westcott wrote a great article on this issue. His research shows that 5 pounds of added muscle increases MR by 200-300 calories a day. This is why bodybuilders can consume enormous amounts of food.

You said:

"Also, your view of how the human body loses fat is not correct. A simple reduction in carbohydrate intake, with no change in energy deficit, will not lead to fat loss. The laws of thermodynamics cannot be broken."

Nothing violates the laws of thermodynamics. But here you are referring to the 1st law only, not the 2nd. (There are 4 in fact.) Referring to the first law is a common error made by many fitness experts.

The human body is not a closed system but an open system. Many studies have shown that by lowering carbohydrate and even increasing caloric expenditure result in a loss of body weight not solely due to water loss. A thermodynamic analysis shows, in fact, that neither are excluded. Meaning, you can lose weight by decreasing calories or by decreasing carbohydrates and not calories. The reason is that thermodynamics only tells us what can happen, not what will happen. That is because thermodynamics only measures initial and final states, not mechanisms. The actual efficiency of fat storage or fat loss, will depend on how things are done inside the body, i.e., what enzymes are used, what hormones are secreted, etc.

When a calorie is a calorie, it is not because of thermodynamics but because of the special and open characteristics of living systems.

In short, your 'calorie is a calorie' argument would support the notion that if I eat 2000 calories of pop tarts or 2000 calories of salmon that my body will deal with these calories in exactly the same way. The 2nd law states otherwise.

Read Gary Taubes book Good Calories Bad Calories. It will open up your eyes to a lot of information that I am sure will delight you. It sure did for me.

[Ricardo]

The idea that exercise doesn't help in weight loss has no scientific basis, as the other commenters already pointed out, and from an evolutionary perspective doesn't make sense. Also, I wonder how people even believe these kind of myths. If exercise was irrelevant for weight loss, you would expect to see quite a few really fat individuals in wekend sport events, at least as much as the percentage of sedentary people. But this is no the reality, most people who pratice some sport, don't have a car and have to walk to work, are generally thiner and healthier. Perhaps this is just an epidemiological association? All very successful weight loss stories start with a couch potato guy turning of the TV, standing up and start walking 7 days/week, 1 hour/day. Forget about Taubes/Cloud fantasy ideas about exercise and please read some Anthony Colpo, starting from pages 74 to 77 from this document: http://www.thefatlossbible.net/They_Are_All_Mad.pdf

[fred hahn]

Mike -

Your link to the King paper doesn't work.

I'm not sure what your point is. Many studies including the one's you've provided indicate that exercise CAN increase energy consumption. So let's not make more of this than that. Anecdotal evidence indicates that this happens as well. Many people eat more and feel they can eat more if they exercise. I own and run a gym and have been a professional trainer for 20+ years. The amount of people who come to me stating that they can't lose weight even though they exercise all the time and eat less fat is legion.

You said:

"I’m not suggesting “relying” on exercise to lose fat, however exercise does provide a benefit above and beyond that of diet alone."

This was not your original point nor did Cloud assert this. Did you read my entire blog or Cloud's entire article? It doesn't seem like it.

Here's what I said:

"Why does exercise have little to no effect on fat loss? There are many reasons including increased appetite and being more sedentary after the workout."

The studies you provided indicated that some people and rats do indeed increase their energy consumption. Some people don't but become more sedentary afterward. Some eat the wrong foods afterward even though energy balance is negative and this can lead to fat gain. Yes you heard that right. A calorie is not always a calorie. Take a look at the 2nd law of thermodynamics.

Here's what Cloud said:

“You should exercise to improve your health…”

And you're right - the Ballard study did look at hunger - I must have overlooked this one. But they concluded:

"...but is associated with a lower relative food intake."

So they all ate about the same amount of calories 2 hours after the one workout as did the non exercise control but since the exercisers exercised they said: "Relative food intake." Again, they overestimate caloric expenditure. This is a typical mistake in these research studies.

And the subjects knew that the study was designed to see how much they would eat - bias can creep in. And did they average out the intake? More than likely. Some of the subjects might have gorged, some not. We don't know.

But yes, this one study seems to indicate that they did not eat more - at least not 2 hours later. However, we don't know what they ate 8 hours later. Some people, like me, are not hungry at all right after an afternoon HIT workout but ravenous at dinner.

For these people, perhaps it's not overeating but being more sedentary later on that keeps them from losing fat. We don't know.

What we know is exercise does little to effect fat loss and that is my and Cloud's main point.

Can you find one good study that shows that exercise alone significantly reduces body fat? I can't.

[Mike]

+1 on the confirmation bias, James. It seems people are very eager to swallow the Taubes cherry-picked data, instead of examining the totality of the evidence.

And you also call him out on the overly simplistic "reduce carbs and fat diappears". Take a look at the metabolic ward studies where both activity and food intake are precisely measured - the magical "carbs are soley responsible" theory is thrown out the window.

The NEAT factor was something I hadn't even gotten to - thanks for addressing it.

[Mike]

Titchenal study:

Titchenal himself concluded the following;

"Energy intake in humans is generally increased or unchanged in response to exercise. When energy intake increases in response to exercise it is usually below energy expenditure, resulting in negative energy balance and loss of bodyweight and fat. Thus, if energy intake is expressed relative to energy expenditure, appetite is usually reduced by exercise."

You said;
"Thus far this one example you have given clearly shows that exercise can indeed induce increased food consumption."

CAN being the operative word. Typical? The weight of evidence does not suggest so. Nowhere did I say exercise NEVER causes increased appetite. The rest of what you wrote about the study is speculation and grasping at straws.

The King paper that you couldn’t access can be found here http://journals.cambridge.org/download.php?file=%2FPNS%2FPNS57_01%2FS0029665198000160a.pdf&code=224c92cc13bb87206ca4bcf617ba24df

A few snippets from this document:
"The relationship between exercise-induced energy deficits and food consumption has been subjected to much scrutiny, and
the evidence suggests that there is no increase in hunger or energy intake as a result of an exercise-induced energy
deficit (Reger et al. 1986; Reger & Alison, 1987; Thompson et al. 1988; Kissileff et al. 1990; King et al. 1994; King & Blundell, 1995)"

"Only one study has created energy deficits using both methods (food deprivation and exercise-induced) in a single study using
the same individuals (Hubert el al. 1997). This study confirmed that the energy deficit created by food deprivation
(meal omission) significantly increased hunger and energy intake, whereas the exercise-induced energy deficit did not."

"Many studies have shown that following a bout of intense exercise (> 60 % maximum O2
uptake) hunger is actually suppressed (Reger et al. 1986; Reger & Alison, 1987; Thompson et al. 1988; Kissileff et al. 1990; King et al. 1994; King & Blundell, 1995)"

Yoshioka study – this was to demonstrate something I forgot to mention – that exercise does impart at least a modest effect in fat loss, despite lower energy intake of the sedentary. Yoshioka’s comment on the issue is as follows;
“Indeed it would seem that in the post-exercise period, high-intensity exercise seems to inhibit energy intake to a greater extent than a low-intensity exercise session of the same caloric cost.”

So much for John Cloud’s assumption that the more intensely you workout, the more ravenous your appetite.

The Dermott study: Limited physical activity is not the same as “no physical activity”. If there were none at all, how would they be able to draw a conclusion on exercise and hunger?

The Slenz and Donahoo studies were mixed in as I intended to present a separate argument about the effect of exercise and thermoregulatory mechanisms.

As for the King studies, Ballard and Lluch and Blundell – the one’s you claim had nothing to do with exercise and appetite – they certainly do.

As I mentioned originally, there are overcompensators as well as restrained and unrestrained eaters that can account for variability in findings. My issue with The TIME article is the implication that exercising turns us into uncontrollable junk-craving zombies – and the more we exercise the more we’ll eat.

I’m not suggesting “relying” on exercise to lose fat, however exercise does provide a benefit above and beyond that of diet alone.

It comes down to common sense – don’t think you can go out and binge on muffins and cheeseburgers and expect to lose fat.

[James Krieger, M.S., M.S.]

I would contend that your arguments here suffer from confirmation bias and an overly-simplistic view of the relationship between human energy expenditure and appetite regulation.

Your contention that increased physical activity will lead to increased appetite is not well supported in the literature. The relationship between energy expenditure and appetite regulation is quite complicated and highly variable from one individual to the next. In fact, some data suggests only a partial energy compensation for exercise-induced energy expenditure. It is quite well established that physically active individuals show better appetite and weight regulation than inactive individuals. This has been strongly shown in long-term weight maintenance studies, where highly active, post-obese individuals do a better job of keeping their weight off than less active individuals, even in the absence of dietary modification.

Also, your view of how the human body loses fat is not correct. A simple reduction in carbohydrate intake, with no change in energy deficit, will not lead to fat loss. The laws of thermodynamics cannot be broken.

There is also a strong set of data on non-exercise activity thermogenesis (NEAT) and body weight regulation. Overall, the data strongly indicates that individuals with high NEAT levels show better weight regulation than individuals with low NEAT levels, even during periods of overfeeding. There is evidence that the drive for NEAT may be partly genetic, hence why it is critical that post-obese individuals must maintain an awareness of their overall physical activity levels and make an effort to maintain high activity during weight maintenance.