# Effects of Time Restricted Feeding and Meal Timing on An 8‐Week Aerobic Exercise Training Programme on Psychological Parameters—A Randomised Controlled Trial

## TL;DR

This study found that combining time-restricted feeding with aerobic exercise had similar psychological effects as exercise alone in young, healthy individuals.

## Contribution

The study provides evidence that time-restricted feeding during exercise does not negatively affect psychological health and may improve positive affect.

## Key findings

- No group differences were found in affect, quality of life, or mood between time-restricted feeding and control groups.
- Positive affect and body image perception improved across all groups.
- Fasting groups showed nonsignificant decreases in eating concerns but slight increases in other eating behavior scores.

## Abstract

Exercise and short‐term fasting may have positive effects on psychological health. The aim of this study was to investigate effects of combining daily time restricted feeding and aerobic exercise on longer‐term psychological health parameters. Fifty‐two participants were randomised into three groups. (1) Training sessions were performed in the fasted state. (2) Training sessions were performed after consuming a standardised carbohydrate‐based snack. (3) Exercise training with an ad libitum diet as a control group. The 8‐week intervention consisted of daily time restricted feeding (16/8h) for both fasting groups and 3x/week à 60‐min aerobic training (∼73% of maximal heartrate) for all groups. Data were collected during pre‐ and post‐test using psychological questionnaires. A 3x2 mixed ANOVA with repeated measures was used to analyse pre to post differences. Thirty‐six participants were included in the analyses. No group‐by‐time interactions were found in any of the investigated parameters, suggesting that fasting groups showed similar effects as the control group. Significant main effects indicate increases in the positive subdomain of the Positive and Negative Affective Scale (p = 0.033; η2
p0.130) and the subdomain vital body dynamics of the Body Image Questionnaire (p = 0.002; η2
p 0.022) over all groups. No significant main effects were observed in quality of life, eating behaviour, and mood. Data suggest that combining daily time restricted feeding and aerobic exercise similarly effects quality of life, mood, affect, as well as eating behaviour compared to exercise alone. Different combinations may be considered as a safe dietary option in conjunction with personal preferences.

Daily time restricted feeding during exercise showed little to no group differences in affect, quality of life, and mood when compared to exercise alone and may not have any negative effects on chronic health and wellbeing in a young healthy population.Choosing fasted over fed exercise seems to be a safe option from a psychological point of view. Especially positive affect might be improved by combining time restricted feeding and exercise.Vital body dynamics (how a person perceives their own body) increased positively in all groups. Both fasting groups showed nonsignificant decreases in eating concerns scores. However, all other eating behaviour scores showed slight positive increases.

Daily time restricted feeding during exercise showed little to no group differences in affect, quality of life, and mood when compared to exercise alone and may not have any negative effects on chronic health and wellbeing in a young healthy population.

Choosing fasted over fed exercise seems to be a safe option from a psychological point of view. Especially positive affect might be improved by combining time restricted feeding and exercise.

Vital body dynamics (how a person perceives their own body) increased positively in all groups. Both fasting groups showed nonsignificant decreases in eating concerns scores. However, all other eating behaviour scores showed slight positive increases.