Researchers at Harvard School of Public Health and Brigham and Women’s Hospital in Boston have found that only one in five people could stick to a low fat diet versus more than half who stuck to a moderate fat diet. What makes this study even more interesting is that only the moderate fat group kept a significant amount of weight off for 18 months.

Half of the 101 overweight men and women in the study were told 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 gourmet 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.”

Successful dieters in the Mediterranean-style moderate fat group increased peanut butter consumption by almost a serving (2 tablespoons) per day, increased peanut consumption by a half a serving (1/2 ounce or a small handful) and mixed nuts by almost a half a serving over their baseline diets. Other foods such as healthy oils (olive, peanut and canola) and avocados were added in small amounts. Surprisingly, those on the moderate fat diet increased consumption of vegetables by one serving per day. Intake of fiber, which most Americans don’t get enough of, was also increased significantly, and the moderate fat group tended to eat more protein compared to their baseline diets. In contrast, the low fat group decreased their consumption of vegetables and fiber compared to baseline.

Peanuts and peanut butter also contain fiber, vitamin E, folic acid, and many micronutrients important to health. Research studies have shown that peanuts and peanut butter can be part of a lower cholesterol diet and that they have a strong satiety value, keeping hunger at bay longer than some other low fat, high carbohydrate foods.