I think a faster metabolism keeps your body working harder an puts more strain on everything like running an engine at higher rpm’s all the time.

If you read studies relating to metabolic rate and life span, a person or animal with a faster metabolism will die younger than one with a slower metabolism.

You can’t halt research entirely, as these advances improve quality of life for human beings.

So you’re left with the option of either being dangerously unethical to humans or rats. Take your pick.

I have never seen anyone getting in any physical shape just by moving around a bit.

In fact, I’m pretty lean right now, though, granted, I also train.

I eat lowcarb (70-150 carbs for me), sometimes less, sometimes more- no need to force myself- most of the carbs from lowcarb bread and nuts, some treats- the rest high fat high protein food).I also have one refeed day, all-you-want to eat.2-3 liters of water.

Now you may say this only works when you’re young, but I helped a 70 year old family-member to lose 25 pounds.If you have a small frame that’s a big difference.Just check it out.

If you want an additional source I only have this dubios site at hand, and I don’t assume you’d buy books just because I say they support my arguments.

Ignore the informal tone and pseudoscience bits, if they bother you:
http://www.t-nation.com/free_online_article/most_recent/2_ways_to_lose_fat_only_1_way_to_get_ripped&cr=

You may as well be asking where is the advantage in living, period – in which case, like your two "examples", you have two options: Life, or death?

Where is the advantage in living long?

But well, at least these western-cannibals have less to worry about when they devour their rich food right now.

Science.

Even if it does cause infertility, if it’s using the same mechanism as what causes infertility during periods of starvation, there’s a simple enough fix: Go off the hormone while you try to conceive. It’s hardly as if human females spend their entire adult lives trying to produce as many babies as possible – unlike some animals (mice, for example).