The same is true of fat cells. Spanish researchers found greater activity in genes responsible for fat breakdown following a diet high in monounsaturated fatty acids. Typical foods include olive oil, canola oil, nuts and avocados. Other diets studied included high saturated fat diets, low-fat, high complex carbohydrate diets and placebo diet (mixed diet). The study showed that the fat composition of diets could influence the activity of fat cells.