Burning the fats

As we exercise to keep the holiday trimmings from garnishing our waistlines, we’re more likely to burn one type of fat, according to a new study by researchers in nutritional sciences.

Wanting to know how different dietary fats are metabolized after exercise, the researchers focused on two types: the saturated fats found in animal products and the monounsaturated fats found in plant-based foods.

To determine fat metabolism, they invited seven women, averaging age 26, to participate in a series of two-day tests. The tests varied in amount of activity: none or light or heavy exercise. Thirty minutes after rest or exercise in the morning, the women were given meals containing the monounsaturated fat, oleate, and the saturated fat, palmitate. The researchers then collected breath samples throughout the day and early night to measure fat metabolism.

The results, published in the November issue of Medicine & Science in Sports & Exercise, show that the women burned significantly more oleate after heavy exercise than they did after rest or light activity. Light activity, though, was also effective. Metabolism of the saturated fat, however, was the same, regardless of activity levels.

Dale Schoeller, one of the paper’s authors, says the findings suggest that people wanting to maintain a healthy body should exercise and modify their diets by substituting monounsaturated fats for saturated ones. But, he adds, the plan’s long-term effectiveness needs further study.