Diet May Affect Gut Hormones Less Than Drugs, Surgery

TOPLINE: 

Adopting low-carbohydrate or low-fat diets over the short term doesn’t change gut-derived appetite hormones at the same levels as observed with pharmacologic treatments or bariatric surgery.

METHODOLOGY:

• Gut-derived hormones play a role in regulating appetite and energy intake, and the circulating concentrations of these hormones can be influenced by dietary macronutrient composition.
• Researchers analyzed postprandial appetite hormone responses and the subsequent energy intake in 20 adults (mean age, 30 years; nine women; body mass index [BMI], 27.8) with normal weight (n = 8), overweight (n = 6), or obesity (n = 6) who followed two different diets during a 4-week inpatient stay.
• Participants followed an animal-based, ketogenic low-carbohydrate diet (10% carbohydrates; 75% fats) or a plant-based low-fat diet (75% carbohydrates; 10% fats) for 2 weeks each in a randomized crossover design.
• At the end of each diet period, participants had liquid breakfast test meals with a calorie content equivalent to their respective diets, and postprandial responses were measured. Furthermore, the ad libitum food and energy intake were assessed for the remaining day, including lunch, snacks, and dinner.
• The concentrations of gut-derived hormones, including glucagon-like peptide 1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), peptide YY (PYY), total ghrelin, active ghrelin, and leptin, were analyzed as postprandial responses at different timepoints.

TAKEAWAY:

• The mean postprandial concentrations of active GLP-1, total GIP, and PYY were significantly higher after low-carbohydrate meals than after low-fat meals.
• The mean postprandial concentrations of total ghrelin, active ghrelin, and leptin were significantly lower after low-carbohydrate meals than after low-fat meals.
• Participants following a low-carbohydrate diet consumed more calories at lunch and dinner, leading to a total daily energy intake higher than that noted in those following a low-fat diet (551 kcal; P
• No significant correlations were found between postprandial gut-derived hormone responses and the subsequent ad libitum energy intake across the day within each dietary pattern.

IN PRACTICE:

“Diet-induced changes in gut-derived appetite hormones are much smaller than those seen with pharmacological intervention or bariatric surgery, suggesting that dietary macronutrient manipulation may not be an effective way of altering energy intake through these mechanisms,” the authors wrote.

SOURCE:

The study, led by Aaron Hengist, PhD, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, was published online in Obesity.

LIMITATIONS: 

Participants had no choice regarding the food options available for consumption but only over the quantity consumed. Differences in appetite hormones could potentially change food preferences or meal timings in everyday situations, which may have affected the energy intake. The use of isocaloric liquid test meals may have not fully represented the effects of solid foods. The inclusion of individuals with different BMIs introduced variability in the findings.

DISCLOSURES:

The study was supported by grants from the Intramural Research Program of the National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health. The authors declared no relevant conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.