Weight gain, especially around the waist, is a problem that many people face as they get older. Although a more sedentary lifestyle, or more fattening diet are often blamed, researchers in the USA have also identified an enzyme which increases levels of fat production. The enzyme, named Aldh1a1, causes visceral fat to build up around internal organs and is linked with type 2 diabetes as well as cancer and heart disease. While the female hormone, oestrogen, supresses this enzyme, once oestrogen levels fall during the menopause its effects increase, causing women to gain weight. Interestingly, this enzyme is also involved in the metabolism of alcohol, which may explain why drinking too much beer or other alcohol tends to show up around the belly for men. Yet another reason to drink within sensible limits! Yet another reason to exercise! The most effective exercise to burn stomach fat is crunches. But you could also try walking, biking, swimming or cycling.