Weight loss, but not dairy composition of diet, moderately affects satiety and postprandial gut hormone patterns in adults

Authors: KRISHNAN, SRIDEVI - University Of California, Davis; ADAMS, SEAN - Arkansas Children'S Nutrition Research Center (ACNC); WITBRACHT, MEGAN - University Of California; Woodhouse, Leslie; PICCOLO, BRIAN - Arkansas Children'S Nutrition Research Center (ACNC); THOMAS, ANTHONY - Jarrow Formulas, Inc; SOUZA, ELAINE - Uc Davis Medical Center; Horn, William; Gertz, Erik; VAN LOAN, MARTA - University Of California, Davis; Keim, Nancy

Submitted to: Journal of Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/5/2020
Publication Date: 11/26/2020
Citation: Krishnan, S., Adams, S., Witbracht, M.G., Woodhouse, L.R., Piccolo, B.D., Thomas, A.P., Souza, E.C., Horn, W.F., Gertz, E.R., Van Loan, M.D., Keim, N.L. 2020. Weight loss, but not dairy composition of diet, moderately affects satiety and postprandial gut hormone patterns in adults. Journal of Nutrition. 151(1):245-254. https://doi.org/10.1093/jn/nxaa327.
DOI: https://doi.org/10.1093/jn/nxaa327

Interpretive Summary: The role of dairy foods as a key contributor to weight loss is still controversial. We conducted a weight loss trial with overweight/obese men and women to determine if, as part of a weight loss diet, the amount of dairy recommended in the Dietary Guidelines for Americans differed from a low amount of dairy with regard to several measures of appetite and food intake. Participants reported how hungry they felt, and blood levels of several hormones known to affect appetite or food intake were measured, along with a test of the amount of food and types of food chosen at a dinner buffet. We found that the amount of dairy in the weight loss diet had little influence on the measures of appetite, but the weight loss intervention did lead to changes in appetite by the end of the weight loss period. These changes included increased levels of desire to eat, an increase in a hormone associated with hunger, and decreases in hormones that are thought to signal a stop to eating. These findings provide further evidence of the difficulty of maintaining weight loss, as hormonal signals arise that manifest as a perceived drive to eat and encourage increased food intake with the goal of returning to the pre-weight loss body weight.

Technical Abstract: Background: Satiety regulation and weight maintenance are intricately linked. How specific dietary components and weight loss influence these systems remains an active area of inquiry. Objective: To evaluate the effect of weight loss with or without adequate dietary dairy servings on fasting and postprandial subjective and objective appetitive measures. Methods: Forty-eight men and women who were low dairy consumers participated in a 12-wk randomized controlled feeding weight loss trial. We compared a low dairy (LD <1 serving dairy/d) to an adequate dairy (AD = 4 servings dairy/d) diet, with a 500 kcal deficit/d. Satiety test day protocols were conducted at the beginning and end of intervention. Test days included 2 fasting blood draws and visual analog scale (VAS) satiety measures (fasting), a standard breakfast meal (25% of total daily energy needs), 5 postprandial blood draws and VAS measures (Post-breakfast), a standard lunch meal (45% of total daily energy needs), and 12 postprandial blood draws and VAS measures (Post-lunch), followed by an ad lib buffet meal challenge. Hormones implicated in food intake regulation (ghrelin, GLP-1, GIP, amylin, CCK, PYY3-36, insulin) were measured. Results: Weight loss, irrespective of treatment, resulted in reduced fasting insulin and leptin, but increased fasting ghrelin, CCK, and desire to eat (p<0.05). When evaluated by treatment groups, fasting CCK trended higher by 33% (0.2 pg/mL) in the AD group compared to LD group (p=0.055), and post-lunch VAS fullness scores were higher (50 mm vs. 45 mm) in the AD group compared to the LD group (p = 0.05). Neither weight loss or dairy intake status significantly impacted dinner buffet feeding outcomes. Conclusions: Weight loss had a stronger effect than dairy intake status on fasting concentrations of ghrelin, insulin, leptin CCK, and an AD diet did not significantly affect most postprandial endocrine or subjective indices of hunger or satiety. The results do not support the hypothesis that dairy influences appetite during weight loss in adult men and women, but the current studies do support the concept that weight loss per se has a modest impact on select systems thought to regulate hunger and satiety.