How would an evolutionary psychologist account for widespread obesity in Western nations?
Westerners tend to reinforce the behavior with foods high in fats and calories.
Westerners have lower rates of metabolism than people from the East.
People naturally crave sweets and fats because this prepared our ancestors to survive famines. Now famine is rare in most Western countries, but people still have the predisposition for these cravings.
Eating foods high in fat content tends to reduce stress levels. There are a lot of stressors in the Western hemisphere, so people are prone to become obese by eating to reduce stress.
In the West, media tends to glamorize fast food and unhealthy lifestyles. People are naturally influenced by the barrage of media images.