Dairy Foods and Weight Loss
Condition: Overweight and Obesity
MeSH terms: Obesity; Overweight; Weight Loss
Study type: Interventional

Summary: 
      Obesity is a national epidemic with multiple causes and complex solutions. Research in both
      animals and humans has suggested that the inclusion of dairy foods into a moderate calorie
      restricted diet can increase weight loss and fat loss. Our proposed project extends these
      prior findings by determining, for the first time, how inclusion of dairy in a
      calorie-restricted diet changes the amount of visceral adiposity in overweight and obese
      subjects. The investigators also propose unique studies to evaluate the potential
      mechanism(s) by which dairy promotes weight and fat loss during dieting, through an
      examination of adipocyte size, gene expression, and inflammatory markers. The hypotheses
      under investigation are (1) that inclusion of dairy foods in a modest energy restricted diet
      will significantly increase body fat loss compared to a control diet; (2) that dairy products
      in a modest energy restricted diet will result in greater fat loss from intra-abdominal
      adipose tissue compared to the control, 3) components of dairy products up- or down-regulate
      the secretion of metabolically-relevant hormones during the postprandial and inter-meal
      periods, 4) dairy products will promote satiety and/or satiation, 5) dairy foods reduce
      adipocyte differentiation and/or enhance adipocyte apoptosis, leading to concomitant white
      adipose tissue (WAT) expression changes for genes playing a role in these processes, 6) dairy
      foods will reduce adipocyte lipid storage and enhance pathways associated with thermogenesis
      and mitochondrial function in WAT, as reflected in gene expression changes and reduced
      adipocyte size, and 7) dairy foods included in a modest energy restricted diet will decrease
      inflammation in WAT and other tissues, thus decreasing circulating cytokines, increasing zinc
      status, decreasing expression of inflammatory markers in WAT, and reducing WAT macrophage
      infiltration.
    

Detailed description: 
      84 overweight and overweight and obese adult males and females will be recruited from the
      faculty, staff, and student populations at University of California-Davis as well as the
      greater Davis and Sacramento communities. Each intervention arm will require 42 adults; 35
      for statistical power on weight loss + 14 more for attrition during the weight loss
      intervention. Statistical power for fat loss requires only 20 subjects/treatment arm.
      Subjects will be enrolled in 7 cohorts of 12 each and will be randomly assigned to either
      control or dairy diets. Subjects will meet the following additional inclusion and exclusion
      criteria:
    

Intervention name(s): high dairy diet; Low Dairy
Intervention type(s): Other; Other
Intervention description(s): 12 week energy restriction with 3-4 servings of dairy foods/day.; less than 1 serving of dairy foods per day.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Basic Science
Keywords: dairy foods; weight loss; fat loss; metabolic regulation