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Comment by kingkongrevenge | Hacker News Reader

> Research suggests that weight may largely be regulated by biology, which helps determine the body's "set point,"

So where did all the fatties come from? They didn't used to be here.

This is ridiculous. There are big, obvious changes in diet and exercise levels since the 70s that have correlated well with rising obesity.

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One theory says that the food you eat can affect your set point. High-calorie, strongly flavored foods that are easily digested (which make up most of the modern American diet) raise your set point. Breaking the flavor-calorie association with flavorless calories supposedly lowers your set point.

http://en.wikipedia.org/wiki/The_Shangri-La_Diet

> High-calorie, strongly flavored foods that are easily digested

I think French cuisine is WAY more flavorful and calorie dense, and they're thin.

The key is portion size. French cuisine may be more dense, but they eat less of it.

It's also about the rate of absorption into your body, as well as the consistency of flavors (packaged food is very uniform, and creates strong associations)

The French have more leisure time than Americans. It's just as much about what going on in your life stress-wise as it is about what you eat.

We have much to learn about life-work balance from the rest of the world. It's unfortunate that some parts of the world look at America and think that they should be emulating us! Please stop that before it's too late.

America needs Mexican siestas and French vacation time in the worst way.

It does seem that the set point is movable. If you've been overweight for 20 years, there may very well be nothing that you can do about it.

An interesting (but very difficult to conduct) study would be an investigation into this particular rubicon of flab. How fat can you become for how long before it is impossible to go back.

That paragraph in the article really got on my nerves, because the whole idea of a "set point" for weight is wrong. There is no set point for weight. The only reason people think there is one is because it's a nice, neat hypothesis. Unfortunately, it is directly contradicted by evidence.

Your body does not try to return to a some weight, but rather resists changes in weight. Given constant diet and exercise, weight will asymptotically settle at some value and stay there. Make a significant change to diet and/or exercise, and the asymptote changes accordingly.

your theory is one theory, and it's the view held by society. does not hold that the set point theory is invalid. I would not be at all surprised if your (extremely complex) body system had an 'equilibrium' weight which it will attempt to normalise itself at, at the translational, post-transcriptional or homonal level. likely a mix of both.

It's not "my theory", but rather the theory I learnt in a Behavioural Neuroscience course. There was a chapter on hunger and eating that spent a good deal of time debunking set point theory. The textbook is "Biopsychology" by Pinel, chapter 12, if you're interested.

If there is such an fixed "equilibrium" weight, there's no evidence for it I know of. I find it curious you call the settling point model "extremely complex", since what I've described so far is very simple: body weight remains constant under constant conditions, and weight changes are dampened by negative feedback. Yours is actually the same so far, but adds a fixed, constant set point.

I agree. White americans, are similiar to Europeans (more like a mix), yet they are a lot fatter. And how do you explain people in North California, or northern VA/DC/Maryland being a lot slimer than people just a state away.

It seems more a enviroment/culturual/city walkability thing

The walkability and culture things are pretty critical, but my armchair opinion is that the biggest factor is fat consumption. Americans eat something like 20% as much fat as they did in the 40s, and the drop off since the early 80s has been fairly sharp. People are eating much less fat and much more starch, with all the insulin and fat storage implications that brings.

Across time and between nations now the role of fat is pretty clear. More fat, thinner people. The recent studies that have put people on high fat, low carb diets are unmatched. People lose the weight and keep it off when you tell them to cut the potatoes and eat butter instead.

People also consume many more calories in places where they didn't in the past. For instance, a soy latte from Starbucks has 210 calories. If you don't change anything in your diet or exercise habits and drink one of these every work day, you'll gain 15 pounds in a year.

I don't know this for sure, but if I recall correctly people eat fewer calories now than they did in the 70s. I know it's not a dramatically different number either way. It's the composition of the calorie that has changed. I'm firmly convinced of the fat vs starch theory. People eat much less fat and oils now and eat more starch.

I doubt I'd recommend replacing fat with carbohydrates, but you're correct in that sugars (starches/carbohydrates break down into...) cause the body to store fat (more specifically, the elevated insulin levels that accompany this).

Regarding weight loss: I work & exercise with a variety of body types (these body types have people names too!), and, within this small sample, I've found that the dominating factor in overall weight is diet, not exercise.

Essentially, exercise controls muscle tone and how "tight" the skin is, while diet seems to control the overall body shape.

Total fat intake and calories have both increased steadily since at least 1849. Starches have jumped up as well starting in the 1970s.

http://www.chiroweb.com/mpacms/dc/article.php?id=38225

I disagree. On average, the Japanese get over 80% of their calories from carbohydrates, and over half from rice alone. They're also the thinnest of all economically developed people in the world, and have the greatest longevity.

Furthermore, in the 1970's the Japanese diet was even more dominated by carbohydrates and people the populace was even thinner. At that time, 75%　of calories were supplied by rice, and close to 90% by carbohydrates in general.

The phenomena isn't restricted to Japan either China is also seeing increasing obesity, heart disease and diabetes as its people living in top-tier and second tier cities adopt diets higher in fat and higher in protein.

The current American diet is actually unusually high in protein and fat by historical (i.e. pre-WWII) standards.

Japanese lifespan and health have improved as fat consumption has risen almost geometrically. The healthiest Japanese are the Okinawans, with the highest fat consumption.

I can't comment on why Japanese have relatively low rates of obesity for the industrialized world with a starchy diet. But the pattern does generally hold true.

> The current American diet is actually unusually high in protein and fat by historical (i.e. pre-WWII) standards.

This is simply wrong with regard to fat. I don't know about the exact change in protein intake, but people eat much less fat and oil now than historically. You can't even get things like beef kidney, suet, or lard anymore at American grocery stores.

The DC metro area has one simple advantage over the surrounding areas: money. There's a very strong correlation between lower and lower-middle income people and obesity. There are too many complex relationships involved to even begin to draw conclusions.

Well perhaps the food levels eaten during childhood determine the set point. By the time you're an adult it's too late.

The number of fat cells becomes fixed by the end of adolescence. As a child, fatty cells proliferate, but remain rather small. Your daily food as a kid influences how many cells you'll end up having as an adult.

Kids nowadays have a horrible diet of sugary drinks and fatty pseudo-chocolate treats.

Fat cells are very much involved in total body weight control, both through enzymes and by hosting lipid-soluble hormones in their oil droplets. So an adult having a lot of fat cells is at a disadvantage in a McBurger world.

"The number of fat cells becomes fixed by the end of adolescence."

Uh, reference? I think you're wrong there. From what I remember, new fat cells grow when weight is gained, and are "deflated", but mostly survive, when weight is lost.

He's probably thinking of human muscle cells.

no - he's absolutely correct. this was discovered earlier this year, IIRC.

cf: http://www.the-scientist.com/blog/display/54629/

This suggests that liposuction is actually an important step if you want to keep fat off.

not necessarily. if the body can somehow keep count, it may just replace the cells you remove. I'm not sure we know for certain either way yet.

My guess would be that that won't happen any more than limbs get regrown. Of course, my guess is pretty worthless. :)

Answer:

http://www.nytimes.com/2008/05/05/health/research/05fat.html...

> Losing or gaining weight affects only the amount of fat stored in the cells, not the number of cells.

BUT

> Every year [..] 10 percent of your fat cells die [...] and are replaced with new fat cells.

So, fat people aren't at a disadvantage by having far more cells.

your skin certainly knows where and when to (re)grow...

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