Researchers at Harvard School of Public Health and Brigham and Women’s Hospital in Boston have found that three times as many people were able to stick to a healthy moderate fat weight loss diet than those following the traditionally recommended low fat diet. Furthermore, they were able to keep the weight off for over 18 months, had better nutritional intakes and were more satisfied because they could eat some of their favorite foods each day such as peanut butter, nuts and healthy oils, in a healthy Mediterranean-style eating pattern. The landmark study was just released in the International Journal of Obesity.
Only one in five subjects could stick to the low fat diet versus more than half who stuck to the moderate fat diet. Both groups lost an average of 11 pounds in the first year. What makes this study revolutionary is that only the moderate fat group kept a significant amount of weight off for 18 months, whereas the low fat group did not. The moderate fat group was followed for an additional year (2 1/2 years total) and still kept a significant amount of weight off.
Half of the 101 overweight men and women in the study were instructed to eat a low fat diet (20% calories from fat) and half to eat a Mediterranean-style moderate fat diet (35% calories from fat, mostly monounsaturated from peanut butter, peanuts, mixed nuts, olive, canola and peanut oils). All participants were given dietary advice to eat a diet of approximately 1200-1500 calories that was low in saturated fat and cholesterol.
Kathy McManus, MS, RD, director of nutrition at Brigham and Women’s Hospital and co-investigator of the study, says, “Any low calorie diet can work in the short run, but we need to know what kind of eating pattern can sustain long-term weight loss – which is key to preventing chronic disease. The subjects substituted high saturated fat foods, like butter, with healthy monounsaturated fat foods, like peanut butter. They tossed nuts on their salad instead of croutons and used small amounts of full fat salad dressings. My patients loved this diet because they could include favorite foods if they carefully watched portion sizes.”