Liquid Meal Replacement Vs. Traditional Food: A Potential Model - Brief Article

Nutrition Research Newsletter, April, 2001

A 1,200 kcal/day balanced diet is considered the preferred weight loss treatment for overweight women who manage their weight primarily on theft own. Very-low-energy diets, pharmaceuticals, and surgery are generally reserved for the morbidly obese and obese patients with weight-associated medical problems. Although a 1,200 kacl/ day diet program should produce weight loss in overweight women, weight regain is probable, as permanent changes in eating and lifestyle habits are difficult to accomplish.

The present study compares the effects on body weight and body composition of two diet plans similar in macronutrients followed over a 1-year period. The study attempted to duplicate free-living by using minimal intervention and enrolling healthy women wanting to lose weight without help from a health professional. The two diets differed from each other, as one plan incorporated liquid meal replacements into the program, and the other followed a more traditional diet plan of low-fat and low-energy foods. Body weight and body composition changes were considered primary study endpoints.

Healthy but overweight women aged 18 to 55 years (BMI 25-32kg/[m.sup.2]) who wanted to maintain a 20- to 40-lb weight loss but claimed difficulty in adhering to changed eating habits after several attempts, were recruited by newspaper advertisement for this study. Subjects were randomized to treatment with either the diet of low-energy/low-fat foods or to the diet of portion-controlled meal replacement shake powder that would replace one or more meals per day. Both plans provided 1,200 kcal/day, with approximately 55% and 15% of total energy from carbohydrate and protein, respectively, and less than 30% from total fat. Intervention was minimal and exercise was not monitored. Lean body mass (LBM), body fat percentage, and fat mass assessments were made at baseline, 3 months, and 1 year. All assessments were made by the same investigator, using the same equipment, following an overnight fast.

All participants were initially provided with several days worth of groceries (including fruits and vegetables). Women following the standard 1,200 kcal traditional food diet received literature containing instructions for weight loss and healthful eating, including sample diets and exchange lists for variety. No counseling was provided. The meal replacement group was instructed to replace three meals per day with a milk-based meal replacement shake (220 kcal, 1.5g total fat, 5g fiber, 15-19g protein). They were instructed to supplement with fruits and vegetables between meals.

Seventy-five (N=75) women enrolled and 64 completed all 52 weeks. Dropouts were evenly distributed between both groups. No significant side effects were reported. Both treatment groups were similar at baseline for age (meal replacement: 36.1 [+ or -] 7.2 years; traditional food: 37.5 [+ or -] 6.2 years) and BMI. At 3 months, subjects from both groups had significant reductions from baseline weight and body fat without loss of lean body mass.

After 1 year, the meal replacement group maintained their initial weight/fat loss, whereas the traditional food group regained most of their initial weight and fat losses. Treatment differences were significant for weight, fat mass, and percent fat, but not LBM. This funding demonstrates that meal replacements may be a useful tool for women unable to alter their eating habits enough to maintain a lower weight. Meal replacements also require a change in eating, but the change is relatively straightforward, involving only one daily meal. This routine provides a constant that reduces daily energy intake, preventing weight regain even if previous eating habits at other meals is restored.

D. Rothacker, B. Staniszewski, P. Ellis. Liquid meal replacement vs traditional food: A potential model for women who cannot maintain eating habit change. JADA 101(3):345-347 (March 2001) [Correspondence: Dana Q Rothacker, PhD, SDA Enterprises, 99 Main Street, Matawan, NJ 07747].