The Atkins diet - and others that limit carbohydrates - are likely to put you in a bad mood, research has found. A team from the Massachusetts Institute of Technology has found carbohydrates help to stimulate production of a key brain chemical called serotonin. It controls our emotions, and a shortage can lead to mood swings and depression. The Atkins diet has become hugely popular despite concerns over its effect on health. Some experts are concerned about whether it might trigger diabetes and kidney damage in the long term. Researcher Dr Judith Wurtman said: "When serotonin is made and becomes...