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

Background Dairy consumption reduces postprandial glycemia and appetite when consumed with carbohydrates. Objectives The objective was to test the effects of frequently consumed dairy products, age, and sex on glycemia, appetite, and food intake. Methods 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 500 mL of a calorie-free control (water), skim milk and whole milk, 350 g Greek yogurt, and 60 g cheddar cheese. Food intake at an ad libitum meal was measured 120 min later. Glycemia, appetite, and gastric hormone responses were measured premeal (15–120 min), within-meal (120–140 min), and postmeal (140–170 min). Effects of treatment, age, and sex and their interactions were analyzed using ANOVA followed by Tukey's post hoc test. Results 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 100 kcal 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 175 kcal after yogurt and cheese and by 82 kcal 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). Conclusions 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.

Integrating Effects of Human Physiology, Psychology, and Individual Variations on Satiety–An Exploratory Study

“…These results agreed in general with reports by other authors ( 22 , 24 – 26 ). These authors highlighted that decrease in pleasantness (e.g., food hedonic and sensory perception), changes in metabolic factors, weakening of appetite-related hormone responses (e.g., CCK and ghrelin), as well as changes in psychological and social factors were potential explanations for the differences in appetite for elderly participants ( 24 – 26 , 50 , 51 ).…”

“…This may indicate that different variables or the combination of them contribute differently depending on the gender group used to develop the PLS models. These results agree with those studies that reported that gender influences satiety, although no significant differences on subjective satiety were reported ( 22 , 48 , 49 ). No statistically significant differences in satiety were found with gender in this study either.…”

“…Similar to gender, the effect of age on satiety has also been reported by different authors ( 22 , 24 , 26 ). In our study, two groups were defined as old (participants age over 46 years) and young (participants age in the range 18–46 years).…”

“…It has been reported by other authors that gender might contribute to explaining satiety ( 22 ). To evaluate the effect of gender on satiety in this study, PLS models were developed for male and female participants separately.…”

“…However, the relationships between psychological factors (e.g., cognition and memory) and appetite, as well as the effects of interactions between human physiology and psychology on satiety are not well-known. In addition, recent studies have highlighted the effect of age, gender, and low satiety phenotype on satiety ( 22 – 26 ). The low satiety phenotype ( 27 – 29 ) is defined as individuals who appropriately recognized their appetite sensations but reported low appetite values and low changes in appetite sensation.…”