Which of the groups have a higher percentage of over-weight people according to one study?

W:Why are so many Americans overweight?
M:Well, that’s a good question,Kate.You’d think that with the current fitness craze in the U.S.,there wouldn’t be so many over-weight Americans.
W:Just how many people are overweight?
M:About 40% of Americans are overweight.Interestingly, one study said that low-income groups have ahigher percentage of over-weight people than higher income families.
W:Are there any other factors like that in the study?
M:Yes. The study also said that the hotter the climate, the lower the percentage of obese people.
W:That makes sense. When it’s hot, you usually don’t feel like eating a lot.
M:Is that why Japanese people are typically skinner than Americans?
W:Well. Our diet has a lot less fat and oil than American food.And Americans eat a lot more fat than we do.
M:You’re right.And we also eat more sugar and junk food. But there’s another reason why so many Americans are fat.
W:What’s that?
M:Nobody exercises any more—not even kids. The average American home has the TV on for six hours a day!
W:Wow! No wonder you Americans are so fat. You don’t get enough exercise.
M:Yeah, I guess so.
W:You really need to watch what you eat and get some exercise.
M:Hey.I started a diet and lost 10 pounds.
W:So what happened?
M:I quit and gained it all back plus 5 pounds.