A lean person’s metabolism can slow down dramatically enough in times of shortage, whereas a fat body in the same situation can suddenly start losing weight very quickly indeed. We must remember that dieting is an artificial manipulation and the body knows it, it is not the same as not having food because the crop has failed.

So just as some people with allergies decide to suck it up and not take the pills or get shots, some fat people choose not to exercise 5 hours a day.
And just as some people with allergies decide not to suck it up and they DO take the pills, some fat people choose to try and lose weight.
There is nothing wrong with either of these, but there is nothing RIGHT about either of these either. Hooray if you want to, hooray if you don’t.

More seriously, though, I think it’s a sad comment on how cowed and fearful we expect people to be that learning a new physical skill as an adult, like exercising when you don’t have the so-called ‘ideal body’ is seen as ‘brave,’ rather than as, you know, a part of life. I mean, with the way the world is, it is often brave, but it shouldn’t have to be.

This explanation makes a lot of sense to me. It should also be a wakeup call to the “bright boys” who think we should somehow try to “eliminate” those genes. They’re there for a reason, one that’s had hundreds of thousands of years to establish themselves. As someone said above, we’ve only had reliable refrigeration and food transport for about a century.

Kua: Someone else more knowledgeable than I can correct me, but IIRC I don’t think they bred the animal populations that were living longer on semi-starvation diets. A *fair* study/comparison would be to look at reproductive rates (i.e. genetic fitness) in higher- vs. lower-calorie populations. My guess would be the stress of breeding would result in a lower life span, and perhaps the low-calorie group might even do worse. But until studies are designed which ask the right questions, we won’t know.

carovee: Since we are unlikely to be able to change the underlying genetic variation in the population, we are unlikely to be able to have a very big impact on the variation in weight in that population.

Populations change their genetic variation all the time – through natural and sexual selection. If you have a subgroup in a population with more fat genes, and they have a higher fertility rate on average, then you will definitely see changes in weight in the population. Even small fractional differential fertility rates produce substantial changes in genetic frequencies over time.

Do they deny coverage to people with food or environmental allergies?

Tho on more than one level I would love it if they could do Genetic testing and find out what each person metabolizes how. What Protein/carb/lipid ratio will make you feel better and healthier? Not what makes most of your neighbors healthier, but YOU, with YOU metabolism and genetics (and I sure as hell don’t mean thinner, I mean Healthier). Some people do better on high protein/low fat/low carb, some people do well on a low-fat vegetarian diet with the bare minimum of Protein for survival. Some people could eat a stick of butter plain every day, and feel energized and ready to take on the world.

Oh, and Meowser on this:
“(Although I strongly suspect many people who make this assumption have never known any Jews, Italians, African-Americans, or Latinos personally, at least not well enough to be familiar with the body habiti of their extended families.)”
You left out us hardy survivors (well descendants anyway) of the Irish Potato Famine. I’m pretty sure everyone in my family metabolizes starches so efficiently we get double the number of calories from each gram.

As one of my aunts said once “come the famine, we’ll see who’s laughin’!”

Heritability is a population based statistic. It does not mean that 77% of an individuals weight is due to genes. It refers to variation within a particular group of people. Variation is a measure of the span of weights around the mean weight for that population (think bell curve). So 77% of the variation in weight is due to variation in some as yet unknown set of genes that exist in that population. Suppose that there are 2 genes related to metabolism and each has 2 variants, so a person can have AaBb or AABB or aaBB, etc.

Since we are unlikely to be able to change the underlying genetic variation in the population, we are unlikely to be able to have a very big impact on the variation in weight in that population.

Umm…thanks, toolbag.

Oh man! This totally reminds me of high school gym class! I played rec league soccer in HS and our goalie was in my gym class. She was quite large and had been her whole life. She was also constantly active but you know, wasn’t going to be a 7 minute miler. She and I were consistently the slowest runners in the class. Of course the douchefaced lean, zippy, popular kids who had finished their mile like, 5 minutes prior would start cheering from the sidelines. And the gym teacher congratulated them for their “sportsmanlike behavior,” never realizing how totally degrading and humiliating that kind of shit was. “woo hoo, run fat girl, you can do it! you can finish a mile without having a fat induced medical catastrophe! (or whatever.)!”

vom.

Stacy, I hate that. One day I had finished my run and was cooling down with a walk on my way back to my car. Some other lady walking by said “Good for you!” I’m sure she thought she was winning the “show empathy by actually talking kindly to fatties award” with that one but it pissed me off. Another time, a fat woman rode by on her bike while I was running and said “You go, girl!” I feel a little more ambivalent about that one–and I did enjoy the fat-chick solidarity–but I still don’t really recommend cheering people on when they’re exercising. No matter what you actually mean, it comes off like you’re encouraging them for “getting started” when you have no idea what their fitness level really is.