Meal replacements are as effective as structured weight-loss diets for treating obesity in adults with features of metabolic syndrome

Abstract

Meal replacements are widely used as a weight-loss strategy; however, their effectiveness outside controlled clinical trial environments is unknown. We compared meal replacements with a structured weight-reduction diet in overweight/obese Australians with raised triglycerides. In a randomized parallel design, 2 groups [meal replacement (MR) and control (C)] of 66 matched subjects underwent a 6000 kJ intervention for 3 mo (stage 1) and a further 3 mo (stage 2). The groups were provided oral and written information. The C group was supplied with shopping vouchers and followed a low fat/energy diet. The MR group was supplied with Slim-Fast™ products for 2 meals (1800 kJ) and consumed a low-fat evening meal. Clients were weighed every 2 wk and received structured supervision without professional dietary input, with compliance assessed by 3-d weighed food records. Blood biomarkers were used to assess fruit/vegetable intake and a questionnaire was used to assess attitudes to treatment. Fifty-five subjects completed stage 1 (withdrawals: 7 in the MR group, 4 in the C group) and 42 subjects completed stage 2. Weight loss was 6.0 ± 4.2 kg (6.3%) for the MR group and 6.6 ± 3.4 kg (6.9%) for the C group at 3 mo, and 9.0 ± 6.9 kg (9.4%) for the MR group and 9.2 ± 5.1 kg (9.3%) for the C group at 6 mo (different over time within but not between treatments). Serum folate and plasma β-carotene were higher in the MR group. Plasma homocysteine fell in both groups (P < 0.005). Dietary fiber intake was higher in the C group (P < 0.02) and calcium was higher in the MR group (P < 0.001). We concluded meal replacement is equally effective for losing weight compared with conventional but structured weight-loss diets. Dietary compliance and convenience were viewed more favorably by participants who consumed meal replacements than by those in a conventional weight-loss program.