Females tend to store more fat subQ and in the lower body (hips, thighs, butt) compared to males (torso viscerally/between organs, then torso and butt subQ) which is said to be a 'protective' way of storing fat...thing is obesity wonks hormones, throw in PCOS and you'll get a female starting to store fat more like a man does (on the flip side it makes them respond better to weight training...). TL:DR - Women are initially less at risk of obesity related health defects. Then the hormones catch up. Also - you cannot be fat and fi (to counter the BBC articlet: http://www.ncbi.nlm.nih.gov/pubmedhealth/behindtheheadlines/news/2015-12-21-the-idea-you-can-be-fat-but-fit-is-a-myth-study-argues/