Meal Replacements and Weight Loss

Peter A. McCullough, M.D.
Division Chief,
Nutrition and Preventive Medicine,
Beaumont Hospital, Royal Oak, Michigan

Many patients may develop heart blockages because they have carried excess body fat for years, which contributes to the cardiovascular risk factors of high blood pressure, diabetes, elevated bad cholesterol, depressed good cholesterol, and increased levels of inflammatory factors in the blood. The Beaumont Weight Control Center has featured the use of meal replacement shakes, bars and entrees for many years.

Have you ever wondered what scientific evidence is really behind these products? Despite the popularity of this approach, until recently, there has been a relative lack of randomized prospective trials comparing meal replacements to conventional food diets. This is primarily due to the fact that when patients are at the point of using meal replacements, they have exhausted all attempts at food diets. Thus, conducting trials on this population has been difficult.

In the April 5th, 2006 issue of the Journal of the American Medical Association, the Pennington CALERIE Team from Baton Rouge, LA, reported the results of a randomized trial comparing four treatments for 6 months: control (weight maintenance food diet); calorie restriction (25% calorie reduction food diet, no exercise); 12.5% calorie reduction food diet with exercise (12.5% calorie restriction plus 12.5% increase in energy expenditure by structured exercise); and a meal replacement program (890 kilocalories per day until 15% weight reduction, followed by a weight maintenance diet-similar to the Beaumont Diet). Patients were mildly overweight to start-averaging approximately 180 lbs.

The meal replacement approach was clearly superior to food diets. In addition, some blood chemistry tests associated with longevity (living a longer healthier life) were improved with weight loss.

Another interesting finding was that those with the higher lean mass (more muscle) burned more calories during the night while sleeping. Collectively, these data suggest that meal replacements (shakes, bars, and entrees) combined with aerobic and strength exercise training to build muscle mass represents the most effective pathway to achieve substantial and sustained weight loss. Moreover, this weight loss method was the only intervention that simultaneously improved multiple cardiovascular risk factors.