Acute effects of time-restricted feeding in low-income women with obesity placed on hypoenergetic diets: Randomized trial.

OBJECTIVE: The aim of this study was to evaluate the acute effects of time-restricted feeding in obese women living in social vulnerability who were placed on diets with the same energy deficit. METHODS: Fifty-eight obese women (19-44 y of age) were randomized to a group with a hypoenergetic diet and 12 h of fasting daily or to a group with only a hypoenergetic diet for 21 d, with body weight and waist circumference monitoring up to 81 d of intervention. The determination of the individual's energy content of the diets was based on their resting metabolic rate (by indirect calorimetry) and physical activity level (by triaxial accelerometers). Body composition, temperature, blood pressure, appetite, adhesion difficulty, thyroid axis hormones, leptin, glucose concentration, and insulin were measured before and after 21 d of intervention. A mixed analysis of variance test was performed. RESULTS: The women had a mean age of 31 y and mean body mass index of 33 kg/m². Significant interaction between group × time was observed only in axillary temperature (0.44°C; 95% confidence interval [CI], 0.17-0.74°C; P < 0.01), which increased in the experimental group and in body fat (-0.75%; 95% CI, -1.43% to -0.07%; P = 0.02) decreased in the experimental group. Also, there was a significant decrease in waist circumference in the time-restricted feeding group after 81 d. There were no differences in hormonal profile, resting metabolic rate, reported appetite, or adherence difficulty. CONCLUSION: Time-restricted feeding may be considered an alternative strategy for treating obesity in socially vulnerable women.