Age and Sex Interact to Determine the Effects of Commonly Consumed Dairy Products on Postmeal Glycemia, Satiety, and Later Meal Food Intake in Adults.

Abstract

Dairy consumption reduces postprandial glycemia and appetite when consumed with carbohydrates. The objective was to test the effects of frequently consumed dairy products, age, and sex on glycemia, appetite, and food intake. In a randomized, unblinded, crossover design, 30 older [60-70 y; BMI (kg/m2): 18.5-29.9] and 28 young (20-30 y; BMI: 18.5-24.9) adults consumed 500mL of a calorie-free control (water), skim milk and whole milk, 350g Greek yogurt, and 60g cheddar cheese. Food intake at an ad libitum meal was measured 120min later. Glycemia, appetite, and gastric hormone responses were measured premeal (15-120min), within-meal (120-140min), and postmeal (140-170min). Effects of treatment, age, and sex and their interactions were analyzed using ANOVA followed by Tukey's post hoc test. All forms of dairy, compared with water, decreased postmeal glycemia, premeal appetite, and meal intake (P<0.0001). Premeal glucose, insulin, and glucagon-like peptide 1 increased, and ghrelin decreased, but effects of dairy differed with age and sex. Older adults had 10% higher pre- and postmeal glucose (P<0.01). Premeal appetite suppression per 100kcal of treatments was more after yogurt than other dairy, but overall appetite suppression was less in older adults than in young adults and in males than in females (P<0.05). Pizza intake was reduced by 175kcal after yogurt and cheese and by 82kcal after milks compared to water (P<0.001). Mealtime reduction for treatment calories averaged 62% after yogurt and cheese but was less at 33% after milks (P<0.05). Compensation was less in older (33%) than in young (63%) adults (P<0.03). Dairy products consumed in usual forms before a meal stimulate metabolic responses leading to reduced premeal appetite, later food intake, and postmeal glycemia, but their effects differ in magnitude and with the sex and age of adults.