"Trans fats could make you fatter than other foods with the same number of calories," Kinzly said, which is shocking. New research indicates that trans fats increase the amount of fat around the belly. These are man-made fats and our bodies have a very hard time digesting them, so avoid hydrogenated oils found in manufactured baked goods such as cookies and crackers, frosting, some brands of margarine and shortening, and candies.