The 14-percent advantage of eating little and then a lot: Is it real?

Health Correlator: The 14-percent advantage of eating little and then a lot: Is it real?

Monday, July 16, 2012

Listen to this article. Powered by Odiogo.com
When you look at the literature on overfeeding, you see a number over and over again – 14 percent. That is approximately the increase in energy expenditure you get when you overfeed people; that is, when you feed people more calories that they need to maintain their current weight.

This phenomenon is related to another interesting one: the nonlinear increase in body weight and fat mass following overfeeding after a period starvation, illustrated by the top graph below from an article by Kevin Hall (1). The data for the squares on the top graph is from the Minnesota Starvation Experiment (2). The graph at the bottom is based mostly on the results of a simulation, and doesn’t clearly reflect the phenomenon.

Due to the significant amount of weight lost in what is called above the semistarvation stage (SS), the controlled refeeding period (CR) actually involved significant overfeeding. Nevertheless, weight was not gained right away, due to a sharp increase in energy expenditure. That is illustrated by the U-curve shape of the weight gain in response to overfeeding. Initially the gain is minimal, increasing over time, and continuing through the ad libitum refeeding stage (ALR).

Interestingly, overfeeding leads to increased energy expenditure almost immediately after it starts happening. It seems that even one single unusually big meal will significantly increase energy expenditure. Also, the 14 percent is usually associated with meals with a balanced amount of macronutrients. That percentage seems to go down if the balance is significantly shifted toward dietary fat (3), probably because the metabolic “cost” of converting dietary fat into body fat is low. In other words, large meals with a lot of fat in them tend to cause a reduced increase in energy expenditure – less than 14 percent. Shifting the balance to protein appears to have the opposite effect, increasing energy expenditure even more, probably because protein is the jack-of-all-trades among macronutrients (4).

The calorie surplus used in experiments where the 14 percent increase in energy expenditure is observed is normally around 1,000 calories, but the percentage seems to hold steady when people are overfed to different degrees (5) (6). Let us assume that one is overfed 1,000 calories. What happens? About 140 calories are “lost” due to overfeeding.

What does this have to do with eating little, and then a lot, in an alternate way? It allows for some reasonable speculation, based on a simple pattern: when you alternate between underfeeding and overfeeding, you reduce food consumption for short period of time (usually less than 24 h), and then eat big, because you are hungry.

It is reasonable to assume, based on the empirical evidence on what happens during overfeeding, that the body reacts to “eating big” as it would to overfeeding, increasing energy expenditure by a certain amount. That increase leads to a reduction in the caloric value of the meals during overfeeding; a reduction of about 14 percent of the overfed amount.

But the body does not seem to significantly decrease energy expenditure if one reduces food consumption for a short period of time, such as 24 h. So you have the potential here for some steady fat loss without a reduction in caloric intake. Keeping a calorie intake up above a certain point is more important than many people think, because a calorie intake that is too low may lead to nutrient deficiencies (7). This is possibly one of the reasons why carrying a bit of extra weight is associated with increased longevity in relatively sedentary populations (8).

Is this 14-percent effect real, or just another mirage? If yes, what does it possibly translate into in terms of fat loss? More on these issues is coming in the next post.


js290 said...
Ned, it should be clear to anyone with some formal mathematics (and/or engineering) training that energy input and energy output are coupled; they can't be treated independently. So any model that tries to decouple these two variables is inherently wrong. The other detail that people miss is when the body will use the energy we ingest. So, even if dietary fat doesn't necessarily provide the maximal increase in energy expenditure, what's important is the ability to ultimately tap the stored fat for energy. As Dr. Rosedale puts it, people don't get fat by eating it, they get fat by not being able to burn it.
igel said...
people on warrior / leangains protocols (myself included) can definitely say that it is NOT a mirage: fasting and then eating big is a cool way to burn fat and build muscle (if one intends to do so) simultaneously
Ned Kock said...
Hi js290. So, would you say that the effect is real, or a mirage? Also, the loss due to EE seems to be lower if the overfeeding is significantly shifted toward dietary fat.
js290 said...
Ned, I would say it's absolutely real. If we can believe that metabolism is slowed by reducing energy input, then it stands to reason that metabolism can be accelerated by increasing energy input. Obviously the relationship is nonlinear; therefore I'm not surprised that dietary fat may have a different effect on energy expenditure. Practically, it doesn't really matter the exact function. As long as the hormones and enzymes are biased towards burning more fat than they store, fat mass will be lost.
vaporizers said...
These are fantastic stuff you shared here.
Ned Kock said...
What I find interesting about this effect js290 is that the body does not seem to significantly decrease energy expenditure if one reduces food consumption for a short period of time, such as 24 h. So you have potential here for fat loss if you alternate between lower and higher calorie intake, as long as you do that in short enough windows of time (less than 24 h). This may be an explanation to the effect that igel mentioned in his comment, associated with some IF approaches.
David Isaak said...
Hi, Ned-- Have you seen this? http://www.sciencedaily.com/releases/2012/07/120702162153.htm Of course, people are fond of noting that people aren't rats--and we really aren't fruit flies! (And, of course, a calorie is no longer a calorie, either. Odd that Bray would be the one to prove it: http://rdfeinman.wordpress.com/2012/03/19/bray-et-al-shows-that-a-calorie-is-not-a-calorie-and-that-dietary-carbohydrate-controls-fat-storage/ )
js290 said...
Ned, it is indeed interesting. I kind of also wonder whether the increase in energy expenditure associated with a "balanced diet" as opposed to a higher fat diet has more to do with the body trying to rid itself of excessive glucose. That is, while one's metabolism is functioning properly, the body will increase energy expenditure by burning off the glucose. But, if the metabolism is operating sub-optimally, the excessive glucose goes into storage. Whereas with with fat, the body is primed to use it for fuel at any time, so an increase in energy expenditure beyond that of a "balanced diet" is not as necessary. It'll increase some because there's more energy to be used, but the body isn't as "panicked" about it. Also, I'm also a bit of an unqualified skeptic when people claim that low carb, per se, breaks their thyroid function, and is somehow restored by introducing dietary glucose. I have to wonder whether people with these experiences simply were not eating enough. And, the re-introduction of carbs simply meant a total increase in energy input. In other words, would they have experienced similar improvements in thyroid function by simply eating more?
Evelyn aka CarbSane said...
Hi Ned, I have to look for it but I came across a study that demonstrated EE actually increases early in a fast. I tend to think if this is true, it goes away with habituation, so erratic IF may be better. That's just a hunch though.
Ned Kock said...
Hi David, thanks for the link. This reminds me of the earlier post on BMI and mortality: http://bit.ly/NWbeMY
Ned Kock said...
I think those are good points js290. There is one problem with a very high fat, low carb diet – neither liver nor muscle glycogen will be properly replenished. Depending on the amount of glycogen depleting exercise done, that type of diet may be unsustainable.
Ned Kock said...
Hi Evelyn. And I am not even considering that possible increase in EE during a fast (or period of calorie restriction), only the one resulting from overfeeding later on.
Jeffrey of Troy said...
This seems to me, as igel alluded to, to support IF + "overfeeding" when you do eat, just enough so that the daily avg over a week or so = what you would have gotten if you did neither. Same calories, different apportionment. Specifically, eat big (esp pro) post-workout (recovery's where you make your gains). But if you ate that big all the time, you'd gain both muscle and fat, like many powerlifters.
David Isaak said...
>>Hi David, thanks for the link. This reminds me of the earlier post on BMI and mortality... Yes, indeed, I thought of your post immediately.
js290 said...
Ned, that's why I go two weeks between glycogen depleting activity. ;-) http://www.youtube.com/watch?v=fQra-ME7vIo#t=47m13s
SEAJ said...
I am curious how the body knows its in a calorie surplus. I would speculate that its the abundance of specific nutrients.. maybe amino acids or glucose levels that cause the effect. Maybe supplementing whole foods with more rapidly digesting amino acids and or sugars at a caloric deficit could simulate the effect.
Ned Kock said...
Hi SEAJ. That is one of the crucial questions, which goes unanswered in the pubs that provide evidence for the 14-percent effect. Well, at least the ones I reviewed.


Whole Health Source: New Review Paper by Yours Truly: High-Fat Dairy, Obesity, Metabolic Health and Cardiovascular Disease

Whole Health Source: New Review Paper by Yours Truly: High-Fat Dairy, Obesity, Metabolic Health and Cardiovascular Disease

My colleagues Drs. Mario Kratz, Ton Baars, and I just published a paper in the European Journal of Nutrition titled "The Relationship Between High-Fat Dairy Consumption and Obesity, Cardiovascular, and Metabolic Disease".  Mario is a nutrition researcher at the Fred Hutchinson Cancer Research Center here in Seattle, and friend of mine.  He's doing some very interesting research on nutrition and health (with an interest in ancestral diets), and I'm confident that we'll be getting some major insights from his research group in the near future.  Mario specializes in tightly controlled human feeding trials.  Ton is an agricultural scientist at the University of Kassel in Germany, who specializes in the effect of animal husbandry practices (e.g., grass vs. grain feeding) on the nutritional composition of dairy.  None of us have any connection to the dairy industry or any other conflicts of interest.

The paper is organized into three sections:

  1. A comprehensive review of the observational studies that have examined the relationship between high-fat dairy and/or dairy fat consumption and obesity, metabolic health, diabetes, and cardiovascular disease.
  2. A discussion of the possible mechanisms that could underlie the observational findings.
  3. Differences between pasture-fed and conventional dairy, and the potential health implications of these differences.

 We wrote this paper because after reviewing the evidence, we found it to be surprising and fairly contradictory to conventional ideas on nutrition and health.  I wrote the sections on obesity, metabolic health and diabetes, Mario wrote the sections on cardiovascular disease and fatty acids, and Ton wrote the section on husbandry practices and dairy fat composition.  Mario was the lead author and did most of the editing/formatting, submitted the manuscript, etc.  Our paper went through a rigorous peer review process.

Here are our basic findings:
  • High-fat dairy consumption is not associated with obesity, in fact, 11 out of 16 studies found that higher dairy fat intake is associated with lower body fat and/or less fat gain over time.  None identified an association between high-fat dairy consumption and fat gain, although some did find an association between low-fat dairy consumption and fat gain.
  • High-fat dairy consumption is not associated with poorer metabolic health.  Six of 11 studies found that higher high-fat dairy consumption is associated with better metabolic health, while only one found that it was associated with one marker of poorer metabolic health (and this study used an odd design). 
  • The association between high-fat dairy intake and diabetes risk is inconsistent.  Zero of eight studies found that high-fat dairy consumption is associated with diabetes risk, and three found that it was protective.  However, three studies also found that low-fat dairy intake was inversely associated with diabetes risk, compared to no association with high-fat dairy, suggesting by inference that the fat content of the dairy could be harmful.  These studies all adjusted for body fatness.  Since body fatness is a key risk factor for diabetes, and dairy fat intake is inversely associated with body fatness, this is obviously a major confound.  We discussed this and other potential confounds in the paper.
  • The evidence on cardiovascular disease is inconsistent, with a number of studies suggesting a protective association, a few suggesting a harmful one, and several suggesting no association.
  • Dairy fat is a complex substance.  There are major differences in the fatty acid composition of dairy from pasture-raised vs. conventionally raised cows, and many of these fatty acids are bioactive and could influence human health.
  • We also discuss the limitations of observational studies in some detail, and many other issues that I won't touch on here.
What This Paper Means

This is the first comprehensive review of studies on the association between high-fat dairy intake and obesity, metabolic, and cardiovascular health.  Typical dietary advice includes the recommendation to eat low-fat or skim dairy products.  This is based on the hypothesis that avoiding the (mostly saturated) fat in dairy will reduce the risk of obesity, metabolic problems, and cardiovascular disease.  This idea is logical, but not every idea that is logical is correct when tested scientifically, particularly when it pertains to a complex natural food.  We asked the question "what does the evidence say about this hypothesis?"

The research to date suggests that high-fat dairy overall does not have a negative impact on obesity risk, metabolic problems, diabetes risk, or cardiovascular disease.  In fact, these studies offer fairly strong support to the hypothesis that high-fat dairy may protect against obesity.  However, there was variability between studies and this may be explained by factors such as a) differences in the quality of dairy products between countries/regions, b) the form in which dairy is consumed (e.g., traditional cheeses vs. ice cream and pizza), and c) other confounding factors discussed in the paper. 

Please keep in mind that these studies are observational and therefore can not establish cause and effect. They're best viewed as a springboard for future research.

What This Paper Doesn't Mean

I want to be very clear about this.  This paper does not mean that adding butter to all your food will make you lose fat or become healthier.  In fact, if you do that you will most likely gain fat and become less healthy.  Say what??  The studies we reviewed examined the role of high-fat dairy in the context of normal varied diet patterns.  They did not compare people eating normally to people who put extra butter on everything, which is an excellent way to increase your calorie intake.  Essentially they compared people eating high-fat dairy to people eating other types of fats as part of a mixed diet.  The difference is subtle but critical to understand: addition vs. replacement. 

So does this mean that replacing other types of fats with dairy fat (pasture-raised in particular), in the context of a normal varied diet, could lead to less fat gain and perhaps even better health over time?  Perhaps.  That is what the studies suggest overall.  But again, these are observational studies with major limitations, so we'll have to wait for more evidence before we can hang our hats on the idea.  In the meantime, it's clear that typical dietary recommendations to favor low-fat dairy over high-fat dairy are on thin ice.


Heart Disease & Cholesterol - review, & listing of key literature by Chris Kresser

Heart Disease / Cholesterol

For the last half century, the medical establishment has vigorously promoted the notion that high cholesterol is a primary risk factor for coronary heart disease, and that a diet high in saturated fat and cholesterol causes heart disease. These hypotheses are widely accepted as fact by many physicians and the general public alike, despite the overwhelming body of evidence that suggests otherwise.

In the following articles, I review over fifty years of research demonstrating that:
  1. High cholesterol is not the primary cause of heart disease.
  2. Diets high in saturated fat and cholesterol don’t cause heart disease.
  3. Consumption of so-called “heart healthy” vegetable oils is linked to heart disease, cancer and many other conditions.
  4. Statin drugs don’t reduce the risk of death for most people, and have dangerous side effects and complications.
I also discuss the latest theories on what causes heart disease and a truly “heart healthy” approach to diet and lifestyle that is supported by both modern science and centuries of traditional wisdom.



Offsite Articles



Handouts from cholesterol talk