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I’ll Take Catch-Up With Those Fries



Yesterday, I attended the “Crosstalk” symposium at ECO 2008 here in Geneva.

Once again, I was fascinated by Abdul Dulloo’s (Co-Chair of the Symposium) talk on the phenomenon of “catch-up” fat.

Simply stated, this phenomenon describes the preferential accumulation of fat tissue as part of any weight-gain process that follows an energy deprived state (See Dulloo’s excellent 2008 review for more on this topic).

Interestingly, this phenomenon occurs irrespective of whether the energy-deprived state is caused by voluntary or enforced starvation, dieting, anorexia or severe illness including sepsis or cancer.

In fact, it even occurs in small-for-gestational-age babies, who manage to rapidly make up for their low birth weight by rapidly tucking away those calories in those chubby fat depots.

Even more interestingly, data suggest that the excess calories that are tucked away are only partly derived from increased caloric intake. Most of them come from preferential partitioning of energy to the fat stores, largely by dramatically turning down skeletal muscle thermogenesis.

This means than even if you are careful not to “overfeed”, your lean tissue will happily deprive itself for the benefit of those fat depots.

In animal experiments, high-fat refeeding appears to make this phenomenon even more pronounced.

All of this appears to be related to substantial insulin resistance that occurs during this “regain” phase and researchers are still trying to figure out what exactly makes the muscle “slow down” in order for the fat to accumulate.

Teleologically all of this makes sense. The idea perhaps is to rapidly take up those calories (following the famine or illness) and store them away – let’s worry about rebuilding the lean mass later.

Unfortunately, at least in animals, this process may be detrimental in the long term. There is now a fairly consistent body of evidence that shows “catch-up” growth to be a risk factor for the development of cardiometabolic risk factors including abdominal obesity, type 2 diabetes, and dyslipidemia – all eventually leading to heart disease.

As regular readers may recall, I recently blogged about the apparent increased risk for the metabolic syndrome with weight cycling – perhaps a reflection of this phenomenon.

Whatever the causes and consequences of catch-up weight, the phenomenon is very real – people tend to get fatter with every diet; patients recovering from cancer tend to put on massive amounts of fat when they recover – most interesting indeed.

What if abdominal obesity is not a consequence of overeating alone but rather a result of past deprivation?

I guess I was not too far off the mark, when the New York Times recently quoted me as saying,”You might want to focus on being as healthy as you can and not obsess about your weight”.

Certainly no point losing weight if it just comes back as fat – i.e. unless you seriously believe you can keep it off by sticking to your weight management strategy for life!

AMS
Geneva, Switzerland

5 Comments

  1. Very interesting -Arya, thanks for sharing the information. Is the weight gain thought to be as visceral or subcutaneous fat?

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  2. Thanks Nana,

    Turns out the fat gain in combination with high fat diet (at least in animals) is also visceral.

    Human data on this issue is unfortunately scanty – seems like clinical researchers haven’t really pounced on this problem with the necessary enthusiasm.

    AMS

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  3. Great blog entry. So, is this the same concept as “starvation” diet which leads to storing calories as fat? For those that have lost weight through low calorie diet and gained back when eating”normally” (storing calories?), can this effect be changed, ie, can the effects of deprivation be neutralized so that calories aren’t being stored when the “famine” has ended and one is eating a normal caloric diet (so eating 1600 calories equates to that and is used by body and not stored?). Thanks. I really enjoy your blog.

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  4. Jill, exercise may help – but at the speed at which weight comes back it may be very difficult for lean body mass to catch up

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  5. This is a fascinating post that raises so many questions and it sent me scurrying to read Dulloo’s papers. I note that in his research, he considers what happened to big populations of people who were starved, e.g. at the siege of Leningrad in 1942.

    I live in a small German town that attracts many retirees. This is the generation of people who were small children in WWII and I know from speaking to some of them that food was extremely scarce at an important stage in their growth, particularly for those who lived in territory that now belongs to Poland.

    Yet these old people do not suffer from obesity. I went out for a walk this morning to observe, and saw many older people who have definite middle aged spread, but saw none suffering extreme overweight or obesity.

    What is interesting is that upper class older people, as identified by expensive clothing, are rake thin. The further down the social scale you go, the more spread you find.

    Yet I am also aware that children conceived and born during, say, the Biafran famine, tend towards obesity today, which bears out Dulloo’s research.

    I also realise my observations are just anecdotal. But, assuming I am observing a real phenomenon, how could a population of people have passed through serious food deprivation and not become fat/obese later when food became plentiful? Similarly, we would expect that the Chinese who had lived through Mao’s famine would now be obese. Is there any evidence that they are?

    There are strong social sanctions here against things like snacking, eating in the street or eating at other times than at meal times, which are still largely home prepared. There is also a culture of biking everywhere, and going for long walks in nature on weekends as part of a group. Which are all healthy behaviours.

    So could this mean that social sanctions and mores, if strong enough, could overcome the biological tendency towards pronounced weight regains that happen after food deprivation?

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  1. Dr. Sharma’s Obesity Notes » Blog Archive » Watch Your Girth - [...] Read related blog posting on Dr. Sharma’s Obesity Notes New York Times May 13, 2008 [...]
  2. Dr. Sharma’s Obesity Notes » Blog Archive » Do Tonsillectomies Promote Overweight? - [...] For a previous post on the possible detrimental effect of catch-up growth click here. [...]

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