title: Diets higher in dairy foods and dietary protein support bone health during diet- and exercise-induced weight loss in overweight and obese premenopausal women.
abstract: BACKGROUND
  Consolidation and maintenance of peak bone mass in young adulthood may be compromised by inactivity, low dietary calcium, and diet-induced weight loss.
  
  
  OBJECTIVE
  We aimed to determine whether higher intakes of dairy foods, dietary calcium, and protein during diet- and exercise-induced weight loss affected markers of bone health.
  
  
  METHODS
  Participants included premenopausal overweight and obese women.
  
  
  METHODS
  Ninety participants were randomized into three groups (n = 30 per group): high protein and high dairy (HPHD), adequate protein and medium dairy (APMD), and adequate protein and low dairy (APLD), differing in dietary protein (30, 15, or 15% of energy, respectively), dairy foods (15, 7.5, or <2% of energy from protein, respectively), and dietary calcium (∼1600, ∼1000, or <500 mg/d, respectively).
  
  
  METHODS
  Serum and urine bone turnover biomarkers, serum osteoprotegerin (OPG), receptor activator of nuclear factor-κB ligand (RANKL), PTH, 25-hydroxyvitamin D, leptin, and adiponectin measured at 0 and 16 wk.
  
  
  RESULTS
  All groups lost equivalent body weight (P < 0.05). N-telopeptide, C-telopeptide (CTX), urinary deoxypyridinoline, and osteocalcin increased in APLD (P < 0.01), whereas in HPHD, osteocalcin and procollagen 1 amino-terminal propeptide (P1NP) increased (P < 0.05), and all resorption markers remained unchanged. P1NP to CTX and OPG to RANKL ratios increased in HPHD (P < 0.005), and P1NP to CTX ratio decreased in APLD (P < 0.05). PTH decreased in HPHD and APMD vs. APLD (P < 0.005), and 25-hydroxyvitamin D increased in HPHD (P < 0.05), remained unchanged in APMD, and decreased in APLD (P < 0.05). Leptin decreased and adiponectin increased in APMD and HPHD only (P < 0.001).
  
  
  CONCLUSIONS
  Hypoenergetic diets higher in dairy foods, dietary calcium, and protein with daily exercise, favorably affected important bone health biomarkers vs. diets with less of these bone-supporting nutrients.
authors: Exercise Metabolism Research Group, Department of Kinesiology, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada.
authors: Andrea R
authors: AR
authors: Josse
authors: Stephanie A
authors: SA
authors: Atkinson
authors: Mark A
authors: MA
authors: Tarnopolsky
authors: Stuart M
authors: SM
authors: Phillips
mesh_terms: D000328:Adult; D001842:Bone and Bones / Q000187:drug effects* / Q000502:physiology; D003611:Dairy Products; D004038:Diet, Reducing; D004044:Dietary Proteins / Q000494:pharmacology*; D005081:Exercise Therapy; D005260:Female; D006262:Health; D006801:Humans; D008875:Middle Aged; D009765:Obesity / Q000178:diet therapy / Q000628:therapy*; D050177:Overweight / Q000178:diet therapy / Q000628:therapy*; D017697:Premenopause / Q000187:drug effects / Q000502:physiology; D015431:Weight Loss / Q000187:drug effects / Q000502:physiology; D055815:Young Adult
chemical_list: D004044:Dietary Proteins