All the stories pointed to research published in Diabetes Care in 2007 on body composition that used three different diets with the same calories but different nutrients. The researchers recruited 11 Spanish volunteers (that is right, only 11 subjects), average age of 62 years, with a family history of diabetes. All were obese and insulin-resistant. All subjects followed the diets for 28 days. One diet was high in carbohydrates; the second was high in saturated fat, and the third was a Mediterranean-type diet that was high in monounsaturated fats.
These heart-healthy fats are found in avocados, olives and olive oil, nuts and seeds and dark or semisweet chocolate. Results showed that weight and fat were unchanged, but when on the high-carbohydrate diet, body-fat distribution was altered and fat tended to accumulate in the gut. That is a bit different than claiming that foods high in monounsaturates shrink belly fat.
Chris Rosenbloom, Ph.D., R.D., a professor of nutrition in the College of Health and Human Sciences at Georgia State University, says, "The authors found that a diet rich in monounsaturated fats prevented (but did not reduce) belly fat from accumulating when compared with a high-carbohydrate diet in older obese men and women, and that has implications for disease prevention. They also reported that insulin resistance was lowered with the Mediterranean-diet type.
"All of the plans restrict calories while including foods rich in the heart-healthy fats. One diet plan called for 1,600 calories a day eaten in four 400-calorie meals. Again, nothing wrong with that diet plan, but let's call it what it is --- a diet that restricts calories. Adding unlimited servings of guacamole, macadamia nuts, olive oil, olives and chocolate without cutting calories will not help much.
"To keep your belly in check, remember the acronym SED --- strength training to preserve muscle mass, exercise aerobically to burn fat and diet should include heart-healthy fat while cutting about 100 calories per day."
From the March 3, 2008, Prepared Foods e-Flash