Wow, I don't remember the last time anyone missed a point by so wide a margin, peppered with several inaccurate assumptions to boot! Well done.
We live in a developed society and, presumably, all of us have regular incomes. We accommodate for our hunger on a daily basis. We plan for it every time we do groceries, prepare meals, save our leftovers, go out for dinner, etc. Yes, one of the reasons we have to be productive members of society is so we can put "food on the table". Yes, our need to eat is not something that can be ignored. But see, unlike primitive man, our hunger is not what pushes us into action. For primitive man, feeling hunger meant "get off your ass and find some food or you will soon die". For us eating is just a biological function that we take for granted as we are easily able to accommodate for it as part of our daily routine. We eat because we're hungry but we choose when we eat, what we eat, how much we eat, and how often we eat because we live in a society that allows us that degree of freedom in accommodating this biological requirement. Hunger is no longer a "driving force" behind our decision-making any more than taking a shit is. None of us have to worry about where our next meal is coming from, so the fact that we get hungry and need food to survive (as vitally important as that is biologically) is actually not at all important when it comes to the important decisions we make about how we live our lives.
Also, the fact that you're claiming obesity is a result of people giving in to their instincts is ridiculous and based on nothing but your "feels". And no, today's fatties wouldn't be the "winners" in the plains of Africa. See, the plains of Africa don't have McDonald's, and the fatties that have been riding the gravy train would learn very quickly that living on the plains of Africa doesn't accommodate that lifestyle, a lifestyle that developed and was allowed to flourish by itsenvironment.