Men and women with thighs over 60cm (23.6in) in circumference have a lower risk of heart disease and early death, a study of 3,000 people suggests.
The relationship remains even when body fat, smoking and blood cholesterol are taken into account, a Danish team says. Those with narrow thighs may not have enough muscle mass to deal with insulin properly, raising the risk of diabetes and, in turn, heart disease, they say. Experts cautioned that the research needed corroborating.
Some said it was too early to change current advice on eating and exercise for heart health, but the researchers said thigh size could be used as a marker for at-risk patients.
The study, published in the British Medical Journal, followed men and women in Denmark for more than 10 years.
They were measured for height, weight and thigh, hip and waist circumference and their overall percentage of body fat was calculated. The thigh measurement was taken just below the gluteal fold, which is the crease caused by your buttocks.
Researchers also looked at the activity levels of the participants, whether they smoked, their blood pressure and cholesterol levels. They then monitored incidence of heart disease over 10 years and death rates over 12-and-a-half years.