A diet free of animal products and low in fat may help with weight loss irrespective of the calories consumed, say scientists in the US. Research at George Washington University in Washington, DC shows that in postmenopausal, overweight women at least, following a low-fat vegan diet for 14 weeks can lead to almost twice the weight loss enjoyed by those on a standard low-cholesterol diet. Lead author Dr Neal Barnard says this may be due to specific metabolic effects, and points out that the diet improves sensitivity to insulin.