Effect of a dairy- and calcium-rich diet on weight loss and appetite during energy restriction in overweight and obese adults: a randomized trial

BACKGROUND/OBJECTIVES: A diet rich in dairy and calcium (Ca) has been variably associated with improvements in body composition and decreased risk of type 2 diabetes. Our objective was to determine if a dietary pattern high in dairy and Ca improves weight loss and subjective appetite to a greater extent than a low dairy/Ca diet during energy restriction in overweight and obese adults with metabolic syndrome. SUBJECTS/METHODS: A total of 49 participants were randomized to one of two treatment groups: Control (low dairy, similar to 700mg/day Ca, -500 kcal/day) or Dairy/Ca (high dairy, similar to 1400 mg/day Ca, -500 kcal/day) for 12 weeks. Body composition, subjective ratings of appetite, food intake, plasma satiety hormones, glycemic response and inflammatory cytokines were measured. RESULTS: Control (-2.2 +/- 0.5 kg) and Dairy/Ca (-3.3 +/- 0.6 kg) had similar weight loss. Based on self-reported energy intake, the percentage of expected weight loss achieved was higher with Dairy/Ca (82.1 +/- 19.4%) than Control (32.2 +/- 7.7%; P = 0.03). Subjects in the Dairy/Ca group reported feeling more satisfied (P = 0.01) and had lower dietary fat intake (P = 0.02) over 12 weeks compared with Control. Compared with Control, Dairy/Ca had higher plasma levels of peptide tyrosine tyrosine (PYY, P = 0.01) during the meal tolerance test at week 12. Monocyte chemoattractant protein-1 was reduced at 30 min with Dairy/Ca compared with Control (P = 0.04). CONCLUSIONS: In conclusion, a dairy-and Ca-rich diet was not associated with greater weight loss than control. Modest increases in plasma PYY concentrations with increased dairy/Ca intake, however, may contribute to enhanced sensations of satisfaction and reduced dietary fat intake during energy restriction. European Journal of Clinical Nutrition (2013) 67, 371-376; doi:10.1038/ejcn.2013.52; published online 6 March 2013