Gut‐derived appetite hormones do not explain energy intake differences in humans following low‐carbohydrate versus low‐fat diets

Abstract Objective The objective of this study was to explore how dietary macronutrient composition influences postprandial appetite hormone responses and subsequent energy intake. Methods A total of 20 adults (mean SEM, age 30 1 years, BMI 27.8 1.3 kg/m 2 , n = 8 with normal weight, n = 6 with overweight, n = 6 with obesity) consumed a low‐fat (LF) diet (10% fat, 75% carbohydrate) and a low‐carbohydrate (LC) diet (10% carbohydrate, 75% fat) for 2 weeks each in an inpatient randomized crossover design. At the end of each diet, participants consumed isocaloric macronutrient‐representative breakfast test meals, and 6‐h postprandial responses were measured. Ad libitum energy intake was measured for the rest of the day. Results The LC meal resulted in greater mean postprandial plasma active glucagon‐like peptide‐1 (GLP‐1; LC: 6.44 0.78 pg/mL, LF: 2.46 0.26 pg/mL; p < 0.0001), total glucose‐dependent insulinotropic polypeptide (GIP; LC: 578 60 pg/mL, LF: 319 37 pg/mL; p = 0.0004), and peptide YY (PYY; LC: 65.6 5.6 pg/mL, LF: 50.7 3.8 pg/mL; p = 0.02), whereas total ghrelin (LC: 184 25 pg/mL, LF: 261 47 pg/mL; p = 0.0009), active ghrelin (LC: 91 9 pg/mL, LF: 232 28 pg/mL; p < 0.0001), and leptin (LC: 26.9 6.5 ng/mL, LF: 35.2 7.5 ng/mL; p = 0.01) were lower compared with LF. Participants ate more during LC at lunch (244 85 kcal; p = 0.01) and dinner (193 86 kcal; p = 0.04), increasing total subsequent energy intake for the day compared with LF (551 103 kcal; p < 0.0001). Conclusions In the short term, endogenous gut‐derived appetite hormones do not necessarily determine ad libitum energy intake. image