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: 49 participants were randomized to one of two treatment groups: CONTROL [low dairy, ~700 mg/day Ca, −500 kcal/d] or DAIRY/CA [high dairy, ~1400 mg/day Ca, −500 kcal/d] for 12wk. 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 percent 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 12wk compared to CONTROL. Compared to CONTROL, DAIRY/CA had higher plasma levels of peptide tyrosine tyrosine (PYY, P=0.01) during the meal tolerance test at wk12. Monocyte chemoattractant protein-1 was reduced at 30 min with DAIRY/CA compared to 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. Registered Trial: ClinicalTrials.gov (NCT00564551).