A High Dairy Protein, High-Calcium Diet Minimizes Bone Turnover in Overweight Adults during Weight Loss

Jane Bowen, Manny Noakes, Peter M. Clifton

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86 Citations (Scopus)

Abstract

Weight loss induces bone resorption and this can be attenuated by calcium supplementation. Protein-rich diets were recently associated with favorable effects on bone density, although this remains controversial. We hypothesized that a diet high in calcium and protein would minimize bone resorption during weight loss compared with a lower calcium, protein-rich diet. The effects of dietary calcium in high protein diets on calcium excretion and bone metabolism were examined in overweight adults (n = 50, BMI 33.4 ± 2.1 kg/m 2) during 12 wk of energy restriction followed by 4 wk of energy balance. Subjects were randomly assigned to isoenergetic diets (5.5 MJ/d, 34% energy from protein, 41% carbohydrate, 24% fat) high in either dairy protein (DP, 2400 mg Ca/d) or mixed protein sources (MP, 500 mg Ca/d). During energy restriction, weight loss was 10% (-9.7 ± 3.8 kg, P < 0.01), and 24-h urinary calcium excretion decreased independently of diet (-1.09 ± 0.23 mmol/d, P < 0.01). By wk 16, the MP diet group had a 40% greater increase in deoxypyridinoline (bone resorption marker) than the DP diet group (P = 0.008). Osteocalcin (bone formation marker) increased from wk 0 to 16 in only the MP diet group [+2.16 ± 0.63 μg/L (+0.63 ± 0.11nmol/L), P = 0.001]. In conclusion, weight loss was associated with increased bone resorption, yet the DP diet had a modest advantage over the MP diet by minimizing overall turnover. Combined with reduced urinary calcium excretion, this suggests that a high-protein, calcium-replete diet may protect against bone loss during weight reduction.

Original languageEnglish
Pages (from-to)568-573
Number of pages6
JournalJournal of Nutrition
Volume134
Issue number3
Publication statusPublished - 1 Mar 2004
Externally publishedYes

Keywords

  • Bone turnover
  • Calcium
  • Dairy
  • Humans
  • Weight loss

ASJC Scopus subject areas

  • Medicine (miscellaneous)
  • Nutrition and Dietetics

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