Saturated Fat Leads to Obesity, Unsaturated Fat Promotes Muscle and Less Body Fat (Eat Your Vegetables, and Fish Oils)
Does it matter what fats you eat? This study in the journal Diabetes, titled “Overfeeding Polyunsaturated and Saturated Fat Causes Distinct Effects on Liver and Visceral Fat“, shows it absolutely does matter. It is likely the difference in whether or not you will become obese, develop type 2 diabetes, and suffer insulin resistance with the increased risks for heart disease and cancer.
The study was a double-blind, parallel-group, randomized trial where 39 young and normal-weight individuals were over-fed muffins high in saturated fat (SFA) in the form of palm oil or polyunsaturated fatty acids (PUFA) in the form of sunflower oil, for 7 weeks. Both groups gained similar weight, but the SFA group had markedly increased liver fat and double the visceral (abdominal fat) of the PUFA group. The PUFA group had a nearly 3-fold larger increase in lean tissue.
You can actually gain lean muscle by eating the right kind of fat. The Mayo Clinic review of fats may be helpful for you to know your fats. Basically, if the fat is solid at room temperature it is more likely saturated. The biggest sources of saturated fats are dairy (cheese, whole milk, and cream) and meats, especially the marbled red meats. My final reference has tables of the good, the bad, and the ugly (saturated fats) and can be viewed here…