The study was done at the Oxford Centre for Diabetes, Endocrinology and Metabolism and has been published in the International Journal of Obesity. Dr Konstantinos Manolopoulos, one of the paper's authors says, “The idea that body fat distribution is important to health has been known for some time. However, it is only very recently that thigh fat and a larger hip circumference have been shown to promote health, that lower body fat is protective by itself.”
The most interesting finding is that the protective effect is independent of weight. However, as you gain weight, both your thigh circumference and your waist circumference increase, thus canceling out the protective effect. “Control of body weight is still the best way to stay healthy, and the advice remains the same: it is important to eat less and exercise more,” notes Manolopoulos.
The researchers explain that fat is stored as fatty acids in various places on the body, which are made available when needed after exercise or fasting. For unknown reasons, thigh fat is used more for long-term fat storage, while waist fat is more often released as fatty acids. These fatty acids float around the body and can get deposited in places like the liver and muscle, where it is harmful. These deposits are associated with illnesses like diabetes and heart disease. Thigh fat seems to avoid this problem by keeping the fatty acids stored over the long term, preventing their deposit in the wrong places. Thigh fat and waist fat also release different levels of hormones. Waist fat releases chemicals called pro-inflammatory cytokines, and inflammation is an important disease process involved in many chronic conditions.
In addition, thigh fat may release more beneficial hormones such as leptin and adiponectin, but more research is needed to confirm this possibility.
Interestingly, gender differences in body shape reflect the health effects of those shapes. At age 40, women are more likely to have more fat on their hips and thighs, while men are more likely to have more fat around the waist. As such, men have a higher risk of diabetes and heart disease at this age. However, as women go through menopause, their body shape often changes and becomes similar to that of men. Their risk of heart disease and diabetes is then the same as for the men.
