I think you’re looking at it backwards. Historically, there were many periods of hardship and nutritional deficiency, and so our bodies would store fat from the “good times” to help tide us over in the “lean times”. We see the same pattern in many (if not all) animal species; they gain weight in time of plenty, and lose it during hard seasons.

In humans, we’ve largely eliminated “survival of the fittest” through medicine and technology, and so when we lack the self control or self discipline to maintain a healthy weight and lifestyle, the effects of evolution are largely mitigated.

I think you are misunderstanding evolution here.

The real world isn’t like pokemon where we gain new abilities through evolution. It’s just a long term weeding out of unfavorable traits.

That said, I doubt there was a time in human history where we were obese, and we didn’t acquire our ability to become obese through evolutionary means. It’s just a byproduct of sedentary lifestyles and shitty food.

Also, evolution doesn’t really work the way it used to anymore in our modern society with medication and that sort of thing. Fat people aren’t exactly being weeded out and disallowed to breed.

More food in than activity and biological needs. Simple.
I am going through it at the moment as I recover from surgery. Food is love.

A taste for fatty and sugary things, back in the day, guided us to eat nutritionally-rich things like ripe fruits and meat. This was a good thing, back when we needed those to get by, and they weren’t necessarily all over the place. Nowadays, that taste has led us into junk food cravings instead of healthy food. Thus, obesity is not only evolutionarily possible, but we’re programmed to do the stuff that gets us there.

Fat people have been sexually desirable in many societies, so more likely to reproduce. It can be a sign of wealth and status. Like a Mercedes or BMW in the US.

I don’t think it has anything to do with evolution. I believe it’s modern food (well, some can’t really be classified as real food anymore, can it? haha). It may be that we crave certain substances, as @laureth has said, and they’re taken advantage of that by producing foods that satisfy that craving, ie junk food, and fatty and sugary stuff, or whatever it is. Few these days are eating only fruits and veggies (which is what i believe we’re meant to eat, but that’s another story) and replacing it with instant, processed foods and whatnot. It’s a way of living, but probably mostly incorrect diet choices, that’s causing people to become obese in my opinion. Also, back in the day one had to move around to get food, now one literally has it delivered to your door for you. People generally, i guess, aren’t as active as they used to be, with desk-type jobs being invented ‘n all.

The “thrifty gene” was adaptive when feast alternated with famine, and people had to work hard to earn their food.

How can obesity not be possible when there’s a fast food restaurant in every corner and technology is making us lazier by the minute. It’s not rocket science. If you eat more fatty foods and move less you will gain weight and if you continue the process you will continue to gain weight until you’re obese.

Of course, as we’ve talked to death on Fluther before, there are causes for obesity that are other than just eating too much. However, in order to be weeded out of the gene pool, these have to prevent a person from breeding. Obesity doesn’t necessarily do that. Fat people can and do have kids. There are some things that can cause obesity and infertility (like PCOS), but the causes would also have to be genetic.

@laureth – i agree, there are some legit medical reasons why some get obese.

For most people getting food is so much easier than it used to be.
My grandmother had to go out and kill the chicken, then pluck and dress it before she could even think about cooking it.
There was no freezer full of greasy goodies to pop in the (non-existent) microwave. There was no KFC on every corner for her. She had to work hard to feed her family and they had to work pretty darn hard too.
So there was less food consumed and more physical work being done.

Perhaps it was useful ( as blubber) during our aquatic period.

Simply consuming more calories than you should and not doing enough activity to burn it off.

Obesity was originally a Darwinian response to famine. The more “food” or fuel stores one could retain during fat times the more resources one had during the lean.

Hey @anartist, scroll up and quit stealing my act.~

Ah, but @dpworkin but you stole @syz act :-P

She’s smarter than I am.

Also lack of sleep and elevated stress messes up your body’s hormones, and interferes with how your body processes fuel stores.

Ghrelin and leptin
Insulin, ghrelin and leptin
Lack of sleep and obesity

Excess fat can also be the bodies response to keeping warm. Eating sweets is more of a recent thing. Many cultures did not have access to sweets but fat was always available to cook with and eat when times were lean. Keep in mind that we also live longer today. In the past, living till 40 was rare. Most people where farmers and worked hard for a living. Now we live long enough to develop thyroid problems, go through menopause or simply old age. Of course eating a big mac till your 60 and sitting behind a desk 8 hours a day doesn’t help.

The cavemen did not use their SUV to go shopping at the nearest grocery store.

Hormones in the food system; factory farming is making us fat.

Because food tastes awesome and some peoples life style revolves around food.. Kinda sad but if they’re happy then why not.