Being overweight is not necessarily a problem being obese is what makes it. It's also a fact that the Americans and the British no less, eat too much processed food and that's where the problem lies. It's not fat or cholesterol but industrialised processed food.
People from cultures that do not have the main western diseases (blood pressure, diabetes, osteoporosis, heart disease and cancer) acquire them once they settle in the USA or UK and adapt to the local life style customs which includes a lack of physical exercise, a loathing for physical exertion.