Dr Chris van Tulleken and Prof Tanya Byron team up with scientists from Oxford and Cambridge universities to see if they can help 75 overweight members of the public win their battle with weight loss. Each dieter undergoes a series of scientific tests to find out the main reason for why they put on weight. The constant cravers have genes that mean they feel hungry all the time, the feasters have a misfiring gut hormone that stops them from knowing when they’re feeling full. The final group, the emotional eaters, eat in response to stress. Each group is put on a specific diet that is tailored to counteract the main reason they put on weight. Will this new approach to dieting be more effective?