n the studys high-calorie, high-fat diet, 45 percent of calories was contributed by fat. For humans, a diet with no more than 30 percent of calories from fat is recommended.
The entire study was conducted in darkness so that the behavior of the animals simply reflected their internal clock; a normal animal has a very fixed daily period of just less than 24 hours. For animals on a high-fat diet, after two weeks on that diet the animals behavior changed: their daily period of sleep/wake was lengthened by a significant amount. This suggests, says Bass, that the central mechanism in the brain that controls the timing of the cycle of activity and rest is affected by a high-fat diet.
Our findings have implications for human disease, said Bass. These basic advances in science can be applied to the studies of common disorders like obesity and diabetes. It is important to understand what happens when diet changes.