The science

The caveman’s curse

Why it is easy to get fat and hard to slim down

See article

Readers' comments



Perhaps the reason that rich people are slimmer is that they have a reserve of money that they can convert to food and this is enough of a motivation to remain slim.


A great deal of research has gone into designing caloric foods that sell well. Some research has developed zero calorie sugar substitutes. These are quite effective at tricking the brain into thinking it is getting some fruit sugar. This shows the brain is "satisfied" by something tasty which may or may not contain any nutrition or any calories. This aspect is, indeed, entirely in one's head. Two points: the food industry has the scientific capacity to develop foods that are satisfying but not fattening. Second: some foods will stave off hunger for a long time although they contain relatively few calories. However, efforts at educating for weight management seem to ignore this (eg. counting calories). The question to ask is "What might I eat for lunch that contains only 300 calories but will keep me from getting hungry until dinner?" (The answer in my case is black walnuts & an orange, but I suspect it differs among individuals. However this choice in not unlike a paleolithic diet).


The author placed willpower and biological causes in juxtaposition. This is an oversimplification. If mental processes are not biological in nature, what is their origin ?


I think it is high time people stop making excuses and rationalizing bad behavior (big boned, genetics, too much sugar...). Eat less than you burn...period! To estimate one's daily caloric needs is fairly simple, then with time and practice one can estimate the caloric count of everything they put in their mouths, average only as much as you need...done! We are going to have to try to social engineer our way out of this using similiar tactics employed against smoking, or the medical costs will be ruinous. Good news we are now aware of the severity of the problem, now we need to gradually and continually create the economic and social disincentives. Take Care!

Sebastien Murat

That's inaccurate, i.e., one does not have to engage in activity to lose weight. But' I'm not suggesting that one starves to death or overcomes an insatiable appetite. It's well known that during torpor (hibernation, estivation, etc.), which is a universal mechanism by which animals (including humans) and plants conserve energy in the face of slim pickings, near-100% fat is preferentially burnt over carbos, and this occurs in the complete absence of any physical activity, appetite, or thirst. Maybe time to go back to the cave and sleep it off!
The Dive Lab

“The evolutionary process has led to a gene pool that is designed to defend body weight against falling below a minimum,” Dr Leibel explains.

This is a partial truth that overlooks the possibility of a sliding minimum set-point. The minimum is set against a back-drop of metabolic rate. If metabolic rate is low, really low, then the minimum `fat´ set-point also down-regulates, and provided you enter this otherwise forbidden zone with sufficient fat stores you can consume the entirety of these stores, and without digging into lean muscle mass.

Sebastien Murat
The Dive Lab

SET Sail

One of the caveman's blessings was that of never sitting for hours: not in a car, not in an office, just not. Walking is more than enough to prevent very wrong processing of insuline, especially straight after a meal.

Why the article does not explain the fundamental role of insuline is a mistery, and the emphasis on psychological factors looks more like excusatio non petita, accusatio manifesta. In essence, move your butt, multiple times a day and 95% of the time you will control your weight.

No Mist

one bicycle. yes one bicycle is all it needs. eat your fill of BigMacs and Lattes. Just remember to get on the bicycle and ditch the car.


No, it's not genetics. When obesity is strongly correlated with consumption of junk (sugary drinks, sugar in everything in the USA) then it's pretty obvious that the problem is excess calories, not genetics. It is true that people are useless in general at eating wisely. They can't resist the super-sized portions, the excessively sweet rubbish found on supermarket shelves. So the answer, quite simply, is not to buy that stuff in the first place. If it's not in the home or on the plate it won't get eaten. There are entire aisles down which I never go when I'm out shopping. There are restaurant chains through whose doors I never step. And in consequence I don't poison my body with the junk most people seem to regard as "normal" these days.

Instead of sitting passively in front of a TV screen or a computer game consol I get off my backside and go for a run, go for a hike, or go to the gym - every day. Sure, I know plenty of people don't much like exercise but... if you don't put in the effort you don't get the rewards. To me it is incomprehensible that some people - the majority, sadly - abdicate responsibility for their own lives. Perhaps there's not much to be done for such folk, aside from pricing junk food above their reach. But I can't help thinking that engineering social change - more bike paths, much higher petrol costs, flex-time and access to gyms at the work location, removal of all food ads on TV and in magazines, removal of "count line" items, etc. would help a lot.

Dr Lou

Couple things...

First, and without believing it a demand for political 'correctness,' I don't like making constant reference to 'fat' people but instead, to those 'overweight or 'obese' based on a correct and clearly provided definition. 'Fat' can be both highly subjective and insulting and many folks, younger women especially and unfortunately, may over focus on 'fat' to the point of self harm even when their body shape and size is anything but.

Second, important points routinely missed in the reference to higher levels of overweight among the poor include the (1) frequent lack of accessible and affordable grocery stores who often refuse to locate in 'poor' neighborhoods with the result that (2) residents are more dependent on corner stores where soda and cheap transfatted candies and cake rule more often because (3) they are affordable and accessible and that (4) starches and other weight producing foods with high glycemic indexes, fat and salt levels combined with starches are more often far less expensive and filling when food purchases an alternatives are very limited.

guest-wnjjiie in reply to Dr Lou

What you say about poor peoples' access to good food choices may be an important factor but it cannot explain everything. I have always been about the same weight and body size my whole life yet my wife has struggled with a constant weight gain over our 30 years together. Clearly we have access to the same food and opportunity to exercise but with totally different outcomes. We both exercise and keep fit but she gains weight and gets fatter around the stomach while I remain the same waist size as I was 30 years ago.

I have always suspected that the answer lies in genetics of the body chemistry. If I have eaten too much I don't feel hungry for a long time and just stop eating, perhaps for an entire day, while my wife's appetite is not suppressed and will continue to eat regular meals after clearly eating too much during a holiday season or some such event.

I wish I knew the reason and could offer an explanation but alas I can only offer the observation.

Dr Lou in reply to guest-wnjjiie

And yours definitely is a valid observation since no single explanation can ever explain much of anything. I would say, however, that remaining the same waist size for 30 years is more to the unusual than otherwise!

Personality and physiological profiles and genetic tendencies definitely impact the potential for weight gain. While some will deal with weight issues throughout their lives regardless of efforts made, others can get away with being far less focused.

At the same time,the poor are much more likely to be overweight based on a host of environmental factors way out of their control. When food stamps and WIC money allows for purchases at farmer's markets, for instance, recipients will typically do so....if, of course, they can get to a farmer's market.

Similarly, chronic hunger and undernourishment leans folks to purchasing foods that are more likely to at least feel filling even if they are not particularly nourishing. (I've actually been there, myself, and can speak to some personal experience.) While your wife may have a higher than typical rate of metabolism leading to a more consistent sense of hunger, lack of access to that which is nourishing similarly can create more frequent hunger.

A glass of water or carbonated soda, for instance, may artificially fill a stomach but will not last very long. Even with different etiologies, the outcome of weight related problems are similar.

Different, however, is that you and your wife can, are able and clearly make an effort to eat well and work out. Chronic poverty dramatically limits access to both balanced food purchases along with ways and the motivation to maintain an exercise regimen.

While our society's slowly increasing body weight is a common concern, understanding how different groups are deferentially impacted is important towards effective prevention and response. An often made argument by too many (not by you but overall) that since the poor tend to be heavier, they are eating just fine is a specious argument which needs context and education.


I am genuinely gob smacked that this article, which purported to be about the science of obesity failed to mention the primary hormonal regulator of fat tissue!!! Instead, it focused on grelin and leptin!! IT IS ALL ABOUT INSULIN!!!!!
Insulin is usually thought to be the hormone responsible for dealing with blood sugar (specifically glucose), which is true, but it is also the hormone that regulates the fat tissue. When Insulin is present in the blood, we store fat, when it is not present or only present in low levels we release fat for energy. This science is not new, it has been agreed and established for at least 30 years.
The question then is, what drives insulin production? Here we turn to the other role of insulin, which I mentioned earlier. It deals with Glucose and therefore is released by the pancreas when we eat foods that are digested to release glucose. In short, carbohydrates.
Eat Carbs -> Glucose spike in the blood -> insulin released -> fat is stored (from both the fat in the diet and the carbs themselves).
Interestingly, if you reduce your carbohydrate intake to low levels, even if you eat a lot of fat you will not store it.
Lastly, the caveman title was misleading, but there is some truth to it. What did our paleolithic and neolithic ancestors eat? Bread? Pasta? Rice? No, because these are products of farming. Thus their intake of carbs was probably very low and what they did eat would have been un-refined and only in season. Today, the bulk of our diet is composed of refined carbs, sugar in particular. It is the significant increase in sugar and refined carbs in the last 30-40 that correlates with the obesity epidemic. I wonder why?

Starscream in reply to SWotton

I totally agree. They forgot to mention the "insuline effect". The author takes more time in explaining the psychological effect (read the power of habit by Charles Duhigg). This is off course important in order to prevent overweight / obesity, but the actual physical cause is the high sugary foods we eat nowadays. Glucose, frutcose, lactose and not to mention the fact that carbohydrates are in essence sugars as well. So we need to carefully become more self aware of the types of food we eat and in which portions. Eating more balanced meals per day (5 to 6 meals) should eliminate the feeling of becoming hungry as your stomach and brain will the have feeling of being "full". Part of all this dieting is exercise. This is inevitable.


The Caveman's Curse is a myth. Instead it is the Caveman's Blessing that is not allowed to do its good work in modern day city life that is the cause of obesity.

A caveman needs to hunt so that he can eat - this is a natural control on obesity. Afterall a pot bellied tiger can't expect to run faster than the slowest antelope - this automatically ensures that the tiger goes on forced diet until his pot belly disappears and he is at last able to overtake the slowest antelope.

Mankind's technological prowess prevents him from going on this forced diet which will automatically control obesity. Genetics, etc. have nothing to do with it - the principle of "survival of the fittest" is losing its hold and "survival of the fattest" has become possible because of technology.


Ahem, Bertie, Sir: May I suggest this article is a weeee bit tooo self absorbed, like navel gazing, or the M-tion word. A better questions, my dear shop keepers, is: why are so few Asians fat compared to those upon whom you mono-focus on in this article? Well Sir!? Is this narrow mono-focus that with which we all REALLY wish to put?

Your humble obedient,


Connect The Dots

Why does most weight loss eventually rebound, resulting in chronic yo-yo dieting?

Answer: The body is returning to it's natural healthy state, the prior overweight status. This physiologic set point is determined genetically.

Genetics plays a role.
Diet and exercise plays a smaller role.
Weight may be as difficult to alter as height.
We are dealt the cards from the time we are born.
You can fight your weight, but it is a lifetime of war.
And your happiness will suffer.

There is well known Competitive Eater And record holder at the Nathan's Coney Island 4th of July Hot dog Eating Contest. Takeru 'The Tsunami' Kobayashi holds the world record for eating 69 hotdogs in 10 minutes. He goes around the world on tour for various competitive eating contests. He has been doing this for over a decade. He still weighs under 130 lbs.

Simple overeating does not cause obesity.
Your genetics must be prewired for you to become morbidly obese.

You may influence to a small extent much like height in children. But you are mostly following your predetermined range.

c_ruz in reply to Connect The Dots

Yes genes do play a part, but not as much as you seem to describe above. I used to be an obese child--basically from 5th grade to 9th grade--in the early 1990s. I attribute it to eating too much junk, drinking too much soda and juice and inactivity (video games). Both my parents were overweight, my grandparents, too. Because I would get made fun of, I decided I would start working out and eating healthier. It took me about 3 years of slow gradual change. Now in my early 30s I am still slim and athletic. I certainly don't live an unhappy existence and enjoy eating healthy food and living an active lifestyle. My success also changed my parents eating habits/lifestyle over the years and they now enjoy a slim active lifestyle, too.

Connect The Dots

There are normal sized people and thin people who have escaped the Obesity Epidemic.

And some of them do not diet, eat like a pig, are ravenous carnivores, and indulge in the buffets.

For them it is extremely hard if not impossible to get fat.


It is not all about DIET.
I know many couples who have been together for decades.
The wife cooks and together, the couple eat the same food for every meal.
But the wife is frumpy and obese.
The husband is still rail thin!
This is the ultimate longitudinal control study.

Most fat people have been on diets all their lives with no avail.

Diets do not work long term. And many do not work short term other than diuresis.

Our bodies have a set 'thermostat' for its weight.
Two young people may start of with the same waist.
But after a few decades, one will balloon and the other keep their same figure from high school.

It is genetics. Your destiny is not hard to predict. It may be no different than height.

Look at your parents:
Tall parents produce tall kids.
Fat parents will likely produce fat kids.
Thin parents will likely produce thin kids.


There are super thin people who are immune to obesity.

Why do we not study these remarkable people?



Products and events


Take our weekly news quiz to stay on top of the headlines

