New research published in the journal Science indicates that, apart from healthy eating and exercise, what decides whether one is thin or fat may also be determined by bacteria in your gut. The role of bacteria that lives in the gut is to digest foods, make vitamins and also amino acids. In a very interesting experiment, researchers looked into human twins wherever they found a fat twin and a thin twin, and took bacteria from their gut and transferred it into mice and the bacteria from the fat twin in each case made the mice fat and bacteria given to mice from the thinner twin led to the mice being more lean. The implications for humans are obvious, but the way that they plan to tackle it is not exactly pleasant sounding. The pleasant way of resolving it is that scientists plan to develop pure mixes of bacteria in future that can be given to fatter people, which will assist them in losing weight but until then, they are going to experiment by transplanting faeces from thin people to fatter people. Right now gym and a diet sounds like a better idea to me!