Another reason to limit saturated fat: Overconsumption promotes fat storage in the abdomen and liver, suggests a small but intriguing Swedish study in the journal Diabetes. Healthy young adults ate 750 extra calories a day from high-fat muffins made either with palm oil (predominantly saturated fat) or sunflower oil (mostly polyunsaturated) for seven weeks.
Both groups gained similar weight, but the saturated fat group accumulated twice as much abdominal (visceral) fat, along with more liver fat. In contrast, the polyunsaturated fat group gained almost three times more lean muscle than the saturated fat group. Visceral fat (the type surrounding internal organs) and fat in the liver increase the risk of heart disease and diabetes more than fat stored elsewhere. The findings support recommendations to partly replace saturated fats with polyunsaturated fats.