Weight loss and consumption of healthy fats as seen in the Mediterranean diet – olive oil, fish, etc. – have been found to help improve cholesterol numbers. Moreover, the results were found to be high in women, specifically women who are insulin-resistant.
In the U.S., 28 percent of American adults are on lipid-lowering drugs, and it has been long known that losing weight and eating well could work to improve cholesterol. The pressing question that still exists is whether or not individuals should lower their fat intake and replace it with carbohydrates or consume more healthy fats.
Principal investigator Cheryl Rock said, “Many diets have said it is okay to eat healthy fats and emphasize olive and canola oils. What we found is that a diet high in healthy oils did lower lipids, but it also lowered both good and bad cholesterol.”
Overweight and obese adults were enrolled in the study, which took place over the course of a year. In this behavioral weight loss program, participants were assigned into one of three diet groups: low-fat/high-carbs, low-carbs/high-fat, and a walnut-rich high-fat/low-carbs diet.
All three diets supported weight loss, but insulin-resistant women benefited the most from low-fat diets, which, however, did not influence lipid levels.
The walnut-rich diet had the greatest benefits to cholesterol, as it lowered LDL and improved HDL.
Rock added, “This weight loss may not put these women at their ideal weight, but it made a significant reduction in their risk of cardiovascular and other diseases. This level of weight loss is achievable and can have a dramatic impact on their quality of life. Diet composition impacts lipid levels, but the critical factor to lose weight continues to be to burn more calories than you consume.”