Many consider obesity to be public-health-enemy No.1. Yet this problem is not new and neither are many of the proposed solutions. Hypotheses on its etiology range from genetics coupled with a "toxic" environment of excess food to individual responsibility and lack of will power, leaving a wide-open field for theories about the best treatment options. Unfortunately, effective therapies with staying power remain elusive as people opt for the latest fads.
Many popular diets advocate restrictive eating and prescribed meals. The scientific underpinnings frequently are suspect, yet followers achieve initial success, likely due to decreased caloric intake. The morbidly obese, with concomitant diseases, such as diabetes and heart disease, seem to benefit from bariatric surgery. But it has risks and does not absolve them from following a healthy and calorie-appropriate eating plan and exercising.
"Programs that seem to be most successful allow for customization of food choices, meal times and must include physical activity on most if not all days," says Cindy Moore, M.S., R.D., director, nutrition therapy, The Cleveland Clinic Foundation, Cleveland, and spokesperson for the American Dietetic Association. "Programs that include a variety of foods are also followed for longer periods of time (and) focus on a mindset of small, permanent changes for life, rather than a meal plan for six weeks, six months, whatever, better support maintaining the weight lost. A one-time approach will not work. Handing someone a meal plan will not work," she adds. Follow-up support or ongoing individualized counseling is necessary.
Researchers continue to search for body regulators, dietary patterns and food components that help in weight loss and maintenance. Decoding the complex hormonal regulation of appetite and fat-storage mechanisms to date has not yielded usable remedies. However, studies point to benefits of some foods and ingredients when incorporated into a balanced, calorie-restricted diet-and-exercise program.
Maximizing the mix
No one really knows the proper mix of carbohydrate, protein and fat for a weight-loss diet. Advocates of conventional low-calorie, low-fat/high-carbohydrate diets and low-carbohydrate, high-protein/high-moderate-fat diets cite thermogenesis, glycemic effect, hormonal and appetite regulation to explain their approaches. Yet clinical studies comparing low-carb and low-fat diets showed an initial weight-loss advantage for low-carb diets at six months but no difference in effectiveness at one year.
Specific foods or ingredients might play a role in managing weight loss. Some studies show that a high-protein/reduced-carbohydrate diet, especially one high in branched-chain amino acids (BCAAs), helps preserve lean body mass and increase fat loss. Additionally, high-protein diets are associated with greater satiety. Among commonly used protein ingredients, whey protein isolates and concentrates are among the highest in BCAAs.
One food-specific study compared the effects of a formula-based low-calorie diet enriched with almonds, which are high in monounsaturated fats (MUFAs), or complex carbohydrates for an overweight and obese population. Those on the almond-enriched diet experienced a greater reduction in weight and other anthropometric and metabolic parameters associated with the metabolic syndrome. Many of the metabolic effects are probably due to higher intake of MUFAs in the almond-enriched diet. However, the enrichment levels of almonds and complex carbohydrates were isocaloric; therefore, weight loss should not have differed between the two groups. The nut's fiber matrix may have lowered the fat absorption and, therefore, the calories' bioavailability. This warrants further investigation as does the use of almonds or other nuts to deliver MUFAs in weight-reduction regimens.