Nutritionists have been telling us for years that all fats are not equal when nutritional value is concerned. The monounsaturated fats in avocado and olive oils are good for us but butter, lard, and the fat in red meat and dairy products are bad. All fats in between have varying degrees of value. Adding to this “all fats are not equal” theory, researchers in Sweden have discovered that some fats make us dangerously fat in the belly while another type is responsible for bulges elsewhere.

Olive oilWhen fat accumulates in the abdomen, it increases the risk for heart disease and diabetes. The Swedish study indicates saturated fats — butter, lard, red meat, and others — deposit extra calories around the mid-section, where it is most risky when it surrounds the liver and other internal organs. Visceral fat, the kind that surrounds the internal organs, causes metabolic disturbances that can trigger metabolic syndrome and diabetes.

Fredrik Rosqvist wanted to see if different fats accumulate differently in the body and his study kept him very busy. He is a doctoral candidate at Uppsala University, first author of the study, and he himself baked the muffins used in the experiment.

For the study 39 young, healthy women and men were recruited to eat one of Rosqvist’s specially prepared 750-calorie muffins every day for seven weeks. Study participants were divided at random into two groups. One group got a muffin made with saturated fat (palm oil), the other group’s muffin was identical in every way except sunflower oil, a polyunsaturated fat, was used instead of palm oil.

The mission was for each study participant to achieve a 3% increase in total body weight by the end of the study. Before the study and after it, each participant’s body fat was measured using magnetic resonance imaging (MRI) scans. Before and after tests for gene activity in visceral fat was conducted also.

After seven weeks of Rosqvist's muffins, both groups gained about the same amount of weight but the saturated fat group had developed much more visceral fat than the polyunsaturated fat group. The polyunsaturated fat group had gained more muscle mass.

It is believed the saturated fat activated genes to store visceral fat but the polyunsaturated fats did not.

Most saturated fats come from animal sources although palm and coconut oils are plant-based saturated fats. Trans-fats, produced by hydrogenation, are saturated fats, too. Saturated and trans fats are solid at room temperature (butter, lard, shortening, coconut oil, etc.) and contribute to clogged arteries that lead to cardiovascular disease.

Polyunsaturated and monounsaturated fats come from plant sources and are liquid and free-flowing at room temperature, just like one’s blood needs to be for best health. Each of the many forms of poly- and monounsaturated fats has its own unique nutritional value but they’re all healthier than saturated fats. Look for pourable fats to cook with whenever possible.

Source: “Abdominal fat accumulation prevented by unsaturated fat.” Uppsala Universitet, Sweden. Uppsala Universitet. Feb 24, 2014. Web. Mar 6, 2014.