24 May 2017 --- A Cambridge University study carried out in mice may help explain why dieting can be an inefficient way to lose weight: key brain cells act as a trigger to prevent us burning calories when food is scarce. "Weight loss strategies are often inefficient because the body works like a thermostat and couples the amount of calories we burn to the amount of calories we eat," says Dr. Clémence Blouet from the Metabolic Research Laboratories at the University of Cambridge.