An Intervention of Four Weeks of Time-Restricted Eating (16/8) in Male Long-Distance Runners Does Not Affect Cardiometabolic Risk Factors

Abstract

Timing of nutrient intake for athletes may affect exercise performance and cardiometabolic factors. Our objective was to examine the effect of time-restricted eating (TRE) on cardiometabolic health. Using a cross-over study design, 15 endurance-trained male runners were randomized to either a normal dietary pattern (ND) first (12 h eating/fasting times) followed by time-restricted eating (TRE) pattern (16 h fast; 8 h eating) or the reverse, with a 4-week washout period between interventions. Body composition, resting energy expenditure, blood pressure and serum insulin, glucose and lipids were measured using standard laboratory methods. Exercise training and dietary intake (calories and macronutrients) were similar across interventions. No significant differences were observed in resting energy expenditure, markers of insulin resistance, serum lipids or blood pressure. Body composition did change significantly (p < 0.05) with whole body fat mass (−0.8 ± 1.3 kg with TRE vs. +0.1 ± 4.3 kg with ND), leg fat mass (−0.3 ± 0.5 kg with TRE vs. +0.1 ± 0.4 kg with ND), and percent body fat (−1.0 ± 1.5% with TRE vs. +0.1 ± 1.3% with ND) declining more in the TRE intervention, with no change in fat-free mass. This study is one of a few to investigate the effects of an isocaloric 16/8 TRE eating pattern in trained endurance athletes and confirms no change in cardiometabolic risk factors. In conclusion, TRE is not detrimental to cardiometabolic health in endurance-trained male runners but could be beneficial on exercise performance by reducing fat mass.

Time-Restricted Eating and Bone Health: A Systematic Review with Meta-Analysis

“…Table 1 summarizes the main characteristics of the included studies. The RCTs were designed as parallel [ 42 , 43 , 44 , 45 , 47 ] and crossover [ 46 , 50 ] studies and were conducted between 2020 and 2023 in three different countries (i.e., USA, China, and Switzerland).…”

“…The included studies comprised a total of 313 adults (203 females and 110 males), with a mean age range between 20.3 to 66.0 years. The trials included healthy individuals [ 46 , 50 ] or participants with specific conditions, including overweight and/or obesity [ 42 , 43 , 44 , 47 ] and metabolic syndrome [ 45 ]. The mean BMI ranged from 21.6 to 33.8 kg/m 2 in the TRE interventions and from 20.3 to 34.4 kg/m 2 in the control groups.…”

“…The mean length of the interventions was 10.5 weeks, ranging between 4 and 24 weeks. TRE interventions were defined as self-selected [ 44 , 45 , 46 , 50 ] or according to the application of specific recommendations and instructions for the timing of food intake [ 42 , 43 , 47 ]. The 16:8 TRE protocol was the most reported in the included RCTs, except for Papageorgiou et al, 2023, which was 12:12 [ 45 ].…”

“…The main control condition applied via the RCTs was to follow usual eating habits and patterns [ 42 , 43 , 44 , 45 , 46 , 50 ]. Two RCTs applied standard dietary instructions or advice for the non-TRE groups [ 45 , 47 ].…”

“…Sensitivity analyses were carried out to assess the robustness of the summary estimates via the leave-one-out method [ 34 ]. Furthermore, additional analyses were conducted while upholding the prevailing health status of the participants included in the RCTs (i.e., overweight and/or obesity) [ 42 , 43 , 44 , 45 ] and the predominant TRE protocol (i.e., fasting window 16:8) [ 42 , 43 , 44 , 46 ].…”