Differential Effects of One Meal per Day in the Evening on Metabolic Health and Physical Performance in Lean Individuals

Abstract

Background: Generally, food intake occurs in a three-meal per 24 h fashion with in-between meal snacking. As such, most humans spend more than ∼ 12-16 h per day in the postprandial state. It may be reasoned from an evolutionary point of view, that the human body is physiologically habituated to less frequent meals. Metabolic flexibility (i.e., reciprocal changes in carbohydrate and fatty acid oxidation) is a characteristic of metabolic health and is reduced by semi-continuous feeding. The effects of time-restricted feeding (TRF) on metabolic parameters and physical performance in humans are equivocal. Methods: To investigate the effect of TRF on metabolism and physical performance in free-living healthy lean individuals, we compared the effects of eucaloric feeding provided by a single meal (22/2) vs. three meals per day in a randomized crossover study. We included 13 participants of which 11 (5 males/6 females) completed the study: age 31.0 ± 1.7 years, BMI 24.0 ± 0.6 kg/m² and fat mass (%) 24.0 ± 0.6 (mean ± SEM). Participants consumed all the calories needed for a stable weight in either three meals (breakfast, lunch and dinner) or one meal per day between 17:00 and 19:00 for 11 days per study period. Results: Eucaloric meal reduction to a single meal per day lowered total body mass (3 meals/day -0.5 ± 0.3 vs. 1 meal/day -1.4 ± 0.3 kg, p = 0.03), fat mass (3 meals/day -0.1 ± 0.2 vs. 1 meal/day -0.7 ± 0.2, p = 0.049) and increased exercise fatty acid oxidation (p < 0.001) without impairment of aerobic capacity or strength (p > 0.05). Furthermore, we found lower plasma glucose concentrations during the second half of the day during the one meal per day intervention (p < 0.05). Conclusion: A single meal per day in the evening lowers body weight and adapts metabolic flexibility during exercise via increased fat oxidation whereas physical performance was not affected.

Keywords: bile acids; energy expentidure; glucose; human; physical performance; postprandial metabolism; time restricted eating; time restricted feeding.

FIGURE 1

Protocols physical performance. In a randomized crossover design, 11 healthy participants consumed all the calories needed for a stable weight in either three meals per day (3 meals/day, breakfast, lunch and dinner) or one meal per day (1 meal/day, between 17:00 and 19:00) for 11 days. (A) Protocol cycle tests including the fat oxidation (% of VO_2max), Wingate and VO_2max tests. (B) Protocol for maximal isokinetic strength, (C) protocol for maximal isometric strength and (D) protocol for maximal jumping height.

FIGURE 2

Results of the continuous glucose monitoring data from both intervention periods. In a randomized crossover design, 11 healthy participants consumed all the calories needed for a stable weight in either three meals per day (3 meals/day, breakfast, lunch and dinner) or one meal per day (1 meal/day, between 17:00 and 19:00) for 11 days. Subcutaneous glucose concentrations were measured from day 5 to day 1,111. (A) Displays the mean of the overall glucose concentrations per hour from day 5 until day 11, whereas, (B) displays the glucose concentrations measured at day 9 (N = 9). Data are presented as mean ± SEM. **p < 0.01 assessed with two-way repeated measures ANOVA, N = number of participants included in statistical analyses and displayed in graphs.

FIGURE 3

Postprandial glucose, insulin, total bile acids and fibroblast growth factor-19 responses. Participants underwent a mixed meal test after 12 days of either three meals per day (3 meals/day, breakfast, lunch and dinner) or one meal per day (1 meal/day, between 17:00 and 19:00). Postprandial responses of (A) glucose (N = 7), (B) insulin (N = 10), (C) total bile acids (N = 10) and (D) fibroblast growth factor 19 (N = 10) were unaffected by the reduced meal frequency (two-way repeated measures ANOVA, all p > 0.05). Data are presented as mean ± SEM. TBA, total bile acids; FGF19, fibroblast growth factor 19; N, number of participants included in statistical analyses and displayed in graphs.

FIGURE 4

Results of the fat oxidation tests from both intervention periods. In a randomized crossover design, 11 healthy participants consumed all the calories needed for a stable weight in either three meals per day (3 meals/day, breakfast, lunch, and dinner) or one meal per day (1 meal/day, between 17:00 and 19:00) for 11 days. The fat oxidation tests were performed at day 10 of both intervention periods. Results (N = 11) of (A) fat oxidation, (B) carbohydrate oxidation, (C) RQ, (D) energy expenditure, (E) lactate, (F) heart rate, (G) Borg scale and (H) relative contribution of fat- and glucose oxidation to energy expenditure. Data are presented as mean ± SEM. **p < 0.01, ***p ≤ 0.001 assessed with two-way repeated measures ANOVA (N = 11). RQ, respiratory quotient; BPM, beats per minute; VO_2max, maximal oxygen uptake volume. N, number of participants included in statistical analyses and displayed in graphs.