When hunger is satisfied, the hormones leptin and insulin signal the brain that it is time to stop eating — an important mechanism in appetite control and weight regulation. In a recent animal study, researchers examined the effects that various types of fat have on this mechanism.

Findings: The saturated fatty acid palmitic acid (found in foods such as butter, cheese and beef) makes its way to the brain and overrides the appetite-suppressing signals from leptin and insulin — and thus triggers overeating. In the study animals, the effect lasted about three days… which may explain why indulging in high-saturated-fat treats on Friday or Saturday can make a person feel hungrier than usual on Monday. In contrast: The monounsaturated fatty acid oleic acid (which is found, for instance, in almonds, avocados, grape seed oil, macadamia nuts, olives, olive oil, peanuts, pecans and sunflower seeds) does not thwart weight-regulating hormones.

Lesson: To make it easier to control your appetite and avoid overeating, steer clear of foods high in saturated fat.