Effects of a single 10-hour daytime fasting intervention on mood and appetite in female adults with and without obesity: a real-world feasibility trial.

Objective: Comparison of the effect of acute daytime fasting on mood, satiety, and neurotrophic factors in females with (OB) and without obesity (N-OB).

Methods: Non-randomized single-arm feasibility trial. Data were collected at an outpatient clinic and from real-world settings. Participants were evaluated after 10 h of nocturnal fasting (T1) and following a 10-hour diurnal fasting period (T2) after consuming a standardized breakfast. Mood, subjective feelings of satiety, food cravings, and neurotrophic factors brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF), and glial cell line-derived neurotrophic factor (GDNF) were assessed.

Results: Fifty-four participants were enrolled in the study [mean age 31 (SD 9)]. One participant from the OB group dropped out before T2, leaving 53 participants (N-OB: n = 29, OB: n = 24). Both groups experienced increased hunger and decreased satiety and fullness after T2. Females with obesity had a greater increase in hunger (p = 0.02). Depression and anger symptoms increased in the OB group, whereas fatigue increased in the N-OB group after T2. NGF increased slightly in the N-OB group after T2, while BDNF and GDNF remained unchanged.

Conclusion: Daytime fasting during daily activities affects mood and eating behavior, especially in females with obesity. Fasting interventions should be tailored to individual needs, considering these differential effects.Trial registration: ClinicalTrials.gov identifier: NCT03532672.