The age-old question of why men store fat in their bellies and women store it in their hips may have finally been answered. It's really all in the genes, says a new study. <br/> <br/>The study found that out of about 40,000 mouse genes, only 138 are commonly found in both male and female fat cells. <br/><br/>The lead author Prof Deborah Clegg of the University of Texas wrote in the 'International Journal of Obesity' that his tems expected the exact opposite – that 138 would be different and the rest would be the same between the sexes. <br/><br/>The study involved mice, which distribute their fat in a sexually dimorphic pattern similar to humans. <br/><br/>Prof Clegg said, given the difference in gene expression profiles, a female fat tissue won't behave anything like a male fat tissue and vice versa. <br/><br/>The notion that fat cells between males and females are alike is inconsistent with the findings.<br/> <br/>In humans, men are more likely to carry extra weight around their guts while pre-menopausal women store it in their butts, thighs and hips. The bad news for men is that belly, or visceral, fat has been associated with numerous obesity related diseases including diabetes and heart disease.<br/> <br/>Women, on the other hand, are generally protected from these obesity-related disorders until menopause, when their ovarian hormone levels drop and fat storage tends to shift from their rear ends to their waists.