Why is there still so much obesity in the united states?

Several reasons: Obesity has increased for several reasons. We've increased our portion sizes, increased our eating of the wrong types of food, i.e. High fructose corn syrup and we've become accustomed to labor saving devices such as elevators, escalators, riding mowers and remote controls. Over the centuries this type of environmental exposure has altered our genes. And so we have childhood obesity passed down.

Lifestyle.: First, technology has made most of us quite sedentary, and as such we don't expend nearly as many calories as we used to. Second, busy lifestyles tend to beget grab-and-go types of foods, which are generally less healthy and actual relaxed sit-down meals. That's one way to see it.

Portions, activity: Portion control and decreased activity due to mechanization are two reasons for obesity. Portion sizes compared to 20 years ago are double, People also tend to eat out more, where portions are less controlled. Many people also have desk jobs and are less active than in the past.