<qa>  What is the reason for overeating?Rationale: Body weight is not well regulated in all individuals. In an obesogenic environment, where overeating is common, some individuals are more prone to weight gain and therefore overweight than others. Yet, the reasons behind this are unclear. Resistant individuals often have higher physical activity levels PALs. It seems that - at higher levels of physical activity and therefore energy expenditure - satiety signals are more precisely regulated, making one better at matching energy intake with expenditure. In other words, active people may not overeat where sedentary people would. However, this does not explain the differences in weight gain observed when subjects all have to overeat imposed overfeeding. It could be that active people are better able to cope metabolically with the extra calories because of already higher levels of carbohydrate and fat oxidation compared to their inactive counterparts. 