title: Red meat, dairy, and insulin sensitivity: a randomized crossover intervention study.
abstract: BACKGROUND
  Epidemiologic studies have linked high consumption of red and processed meat with risk of developing type 2 diabetes, whereas high dairy consumption has been associated with decreased risk, but interventions have been limited.
  
  
  OBJECTIVE
  We compared the effects on insulin sensitivity of consuming a diet high in lean red meat with minimal dairy, a diet high in primarily low-fat dairy (from milk, yogurt, or custard) with no red meat, and a control diet that contained neither red meat nor dairy.
  
  
  METHODS
  A randomized crossover study was undertaken with 47 overweight and obese men and women divided into 2 groups as follows: those with normal glucose tolerance and those with impaired fasting glucose or impaired glucose tolerance. Participants followed the 3 weight-stable dietary interventions for 4 wk with glucose, insulin, and C-peptide measured by using oral-glucose-tolerance tests at the end of each diet.
  
  
  RESULTS
  Fasting insulin was significantly higher after the dairy diet than after the red meat diet (P < 0.01) with no change in fasting glucose resulting in a decrease in insulin sensitivity after the high-dairy diet (P < 0.05) as assessed by homeostasis model assessment of insulin resistance (HOMA-IR). A significant interaction between diet and sex was observed such that, in women alone, HOMA-IR was significantly lower after the red meat diet than after the dairy diet (1.33 ± 0.8 compared with 1.71 ± 0.8, respectively; P < 0.01). Insulin sensitivity calculated by using the Matsuda method was 14.7% lower in women after the dairy diet than after the red meat diet (P < 0.01) with no difference between diets in men. C-peptide was not different between diets.
  
  
  CONCLUSIONS
  In contrast to some epidemiologic findings, these results suggest that high consumption of dairy reduces insulin sensitivity compared with a diet high in lean red meat in overweight and obese subjects, some of whom had glucose intolerance. This trial was registered at the Australian New Zealand Clinical Trials Registry as ACTRN12613000441718.
authors: From the School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, Australia.
authors: Kirsty M
authors: KM
authors: Turner
authors: From the School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, Australia.
authors: Jennifer B
authors: JB
authors: Keogh
authors: From the School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, Australia. peter.clifton@unisa.edu.au.
authors: Peter M
authors: PM
authors: Clifton
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D015992:Body Mass Index; D018592:Cross-Over Studies; D003611:Dairy Products; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000178:diet therapy; D004032:Diet; D015930:Diet Records; D002149:Energy Intake; D005215:Fasting; D005247:Feeding Behavior; D005260:Female; D005951:Glucose Tolerance Test; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D008297:Male; D008460:Meat; D008875:Middle Aged; D015596:Nutrition Assessment; D009765:Obesity / Q000150:complications / Q000178:diet therapy; D050177:Overweight / Q000150:complications / Q000178:diet therapy
chemical_list: D001786:Blood Glucose; D007328:Insulin
keywords: dairy; dietary proteins; insulin sensitivity; red meat; type 2 diabetes