Apple and pear shape Storing more fat on your hips, bottom and thighs actively protects against diabetes and heart disease, according to a report from Oxford University scientists in the International Journal of Obesity.
The impact of body fat distribution on health has been known for some time, says the team from the Oxford Centre for Diabetes, Endocrinology, and Metabolism (OCDEM). However, according to Dr Konstantinos Manolopoulos, one of the study’s authors, "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."
According to the team, one of the main differences between belly fat and hip and thigh fat is the way the body uses the fat tissues to store energy in the form of fatty acids, which can be released when needed. For example, fat around the waist is much more active in storing and releasing fatty acids in response to need throughout the day, while thigh fat is used for longer term storage.
So more waist or abdominal fat tends to lead to more fatty acids floating around the body where it can get deposited in other organs like the liver and muscle, and cause harm. This is linked with conditions like diabetes, insulin resistance and heart disease. Thigh fat on the other hand, traps the fatty acids long-term, so they can’t get deposited and cause harm.
Dr Manolopoulos says the typical difference in male and female body shapes, with men more likely to have fat around the waist and women usually having more fat on their thighs and hips, illustrates the health effects of different body shapes.
"If you looked at a man and woman of the same weight and aged around 40, they would have different weight distributions, and it would be the man that was at higher risk of diabetes and heart disease," he says.
"However, when women go through menopause, as well as changes in their hormones they tend to see a change in body shape. They lose body fat and move to a more ‘male’ fat distribution. They then have the same risk of heart disease and diabetes as men.”
Unfortunately the prospect of using these findings to reduce people’s health risks is a long way off, says Dr Manolopoulos.
"We don’t really know how the body decides where to store fat. At the moment we need to understand more about the mechanisms the body uses. Only then will we be able to take the next step and try to influence this.
"In principle, this should be possible. There is a class of anti-diabetic drugs that is known to redistribute fat in the body from internal organs to fat stored subcutaneously under the skin. This improves symptoms in diabetes," he says.