Author(s): KNEFFEL, Z., CANTRELL, G.2, MURLASITS, ZS.3, Institution: HUNGARIAN UNIVERSITY OF SPORTS SCIENCE, Country: HUNGARY, Abstract-ID: 265

INTRODUCTION:
Nutritional habits have a considerable effect on exercise performance as they determine both acute energy availability for sport activities, and long-term changes in body composition (BC) (muscle mass (MM) and fat mass (FM)). The aim of the study was to summarizes the available evidence on the effects of within-day energy balance on FM and MM in athletes.
METHODS:
The systematic search strategy executed via the databases of Embase, PubMed, Scopus, SportDiscus and Web of Science using the combination of the following terms: meal frequency, eating frequency, feeding frequency, meal pattern, eating pattern, feeding pattern, meal distribution, eating distribution, feeding distribution, within-day energy balance, within-day energy deficit, body composition, lean mass, muscle mass, and athletes. Inclusion criterion were: athletes, over 14yrs, report data on the BC and energy balance within a day, full text, peer-reviewed papers and published in English language.
RESULTS:
The search identified 3831 unique papers; 20 were suitable for full text assessment and 7 papers were included in the systematic review. From the seven papers two used meal frequency as an indication of energy distribution, while five calculated hourly energy surplus and deficit to determine within-day energy balance. The average score on the PEDro scale checklist was 4 and none of the included studies was of poor (score less than 4) quality. Findings revealed that within-day energy balance is a significant factor in the regulation of body composition in athletes, and that negative within-day energy balance may impair muscle protein synthesis and promote fat accumulation. During food restriction (weight cutting), a more frequent meal schedule may help preserve LM and reduce FM by maintaining a higher metabolic rate and stimulating protein synthesis. During weight gain, a large 24-hour energy surplus ensures continuous positive energy balance, and the timing and the frequency of meals are not as important.
CONCLUSION:
Assessment of hourly, rather than daily energy balance would assist with the development of tailored approaches to target energy balance to enhance performance and BC of athletes. Consuming high glycemic index carbohydrate and protein rich snack within ~30 minutes after exercise seems beneficial to replenish glycogen stores and promote muscle remodeling. Large 24-hour energy surpluses may be sufficient for athletes aiming for lean mass gain, as meal timing and frequency become less critical in such scenarios.