Weight loss using meal replacements high in glycomacropeptide-enriched whey powder

Abstract

Cholecystokinin (CCK) is a peptide hormone that causes gallbladder contraction and pancreatic enzyme secretion for the digestion of protein and fat. It is also thought to have a role in satiety. It has been reported that glycomacropeptide (GMP) stimulates the release of CCK and may contribute to increased satiety and reduced energy intake. The aim of this study was to examine after six months whether greater weight loss could be achieved with a GMP-enriched whey powder meal replacement compared to a skim milk protein powder meal replacement. In a randomised, double blind, parallel design, body composition measured by dual-energy X-ray absorptiometry (DEXA) and cardiovascular disease (CVD) risk factors were measured at baseline and 6 months. The weight loss strategy used meal replacements (MR) containing 33 g protein from GMP-enriched-whey-protein-isolate, or skim-milk-protein-powder (SMPP) and 954kJ kJ/sachet. Volunteers were asked to consume 2 MR/day instead of 2 meals for 6 months. One hundred and twenty seven participants (34 men, 99 women, 95.5± 15.4 kg, BMI 33.4±3.4 kg/m2, 50.0± 12.4 yr) commenced and 82 completed the 6 month study. After 6 months weight loss was 9.5±5.8 vs 11.0±6.0 kg, GMP and SMPP respectively (p<0.001 compared with baseline) with no differences between treatments. Total and LDL-cholesterol, triglycerides, glucose, insulin, systolic and diastolic blood pressure decreased at 6 months (All p<0.01 compared with baseline with no difference between treatments). We conclude that weight loss using dairy protein-based meal replacements achieved a clinically meaningful weight loss with benefics on markers of CVD risk but GMP had no additional effect using this study design.