Not all fat is bad fat—in fact, there are several kinds of fats that are actually beneficial in weight loss, Omega 3 fatty acids being one of them. Known as polyunsaturated fatty acids, Omega 3′s cannot be produced in the human body. But they can be found in foods like fish and nuts. In a 2006 study of obese and overweight women, scientists found a direct correlation between higher Omega-3 levels and smaller waist size, lower hip size, and healthier BMI. Though researchers are not exactly sure what causes these results, they speculate that these fatty acids increase fat burning and increase a feeling of fullness, by impacting the hormones associated with hunger and appetite.