DON'T DO CARDIO - Must Read!

On the topic of ancestors, forgive me if I'm wrong, but don't we all have ancestors from different parts of the earth? For example, some were ice fisherman, some fished from boats, some hunted buffalo, and so on. Everyone is different. I'm not an expert, but it seems to me that their bodies adapted to their needs. Since we all are different, this explains why my friend can eat fast food and drink mountain dew all day, never exercise, and still be very thin, while I exercise and count my calories and continue to struggle with my weight.

Depends on how far back you go. You could arguably say we all came out of Olduvai Gorge. Buffalo didn't come until well after humans migrated to North America 14,000'ish years ago. Fishing dates to a mere 40,000 years ago. We were human long before we were tool using hunters.

The reason why some of your friends can drink mountain dew and eat pizza all day while you would become grossly obese doing the same thing is not because their ancestors for millions of years consumed those foods and thus adapted to them, while yours did not. It is because they are in better touch with their instincts that tell them when to eat and when to stop. Most of us were trained not to listen to those instincts. Getting in touch with our hunger and respecting it will take us a long way toward achieving our goals and maintaining our weight longterm.