to ascertain which foods are healthy or unhealthy the. results can vary greatly depending on the method used. intervention studies tend to produce better results but they're also more expensive here each participant receives exact instructions for what to eat the german institution of human nutrition has teamed up with billions sherry take clinic to carry out a study of this kind the scientists are investigating high fat mediterranean food adapted to german tastes they're comparing that with a low fat diet along the guidelines of the german nutrition society. one group is told to eat lots of fruits and vegetables and along with whole grain products a moderate amount of dairy produce really nice and fish. the other group is eating a high fat low carb mediterranean diet with pulses nuts fish