LOW-calorie substitutes in food and drink may actually make dieters pile on the pounds, scientists claim. Researchers discovered that the taste of fat and sugar gears the body up to expect a high-calorie hit. When it doesnt come the bodys mechanism for controlling food intake becomes confused, making us eat more. An American research team from Purdue University carried out a series of experiments on laboratory rats. Prof of psychological sciences Susan said: 'Substituting a part of the diet with a similar tasting item that has fewer or zero calories sounds like a common-sense approach to lose weight, but there are other physiological functions at work. MO