The impact of later eating rhythm on childhood adiposity: protocol for a systematic review

Features of Pupils in Each Dinner Habit: Non-late Regular, Regular but Late, and Irregular

Background:

Both late and irregular caloric intakes are becoming common, especially among young adults. This study aimed to investigate features of pupils in Japan following different dinner habits.

Methods:

Dinner habits were categorized into 3 types: non-late regular, regular but late, and irregular. Questionnaires of 2722 pupils in grades 5 to 12 were included, and a multiple comparison test was conducted to investigate the differences of lifestyle factors among the 3 dinner-pattern categories.

Results:

Only half of grade 5 and 6 pupils had non-late regular dinners. The rate of pupils who had regular but late dinners increased from elementary school (11.8%) to senior high school (41.1%) via junior high school (15.1%). More than 30% of pupils took dinner irregularly. The pupils taking non-late regular dinner showed the earliest bedtime and the longest sleep duration among the 3 dinner-time habit categories and also revealed the best academic performance and sleepiness scores. The pupils taking regular but late dinner showed the highest grade, the latest bedtime, the shortest sleep duration, the longest school-day screen time scores, and the worst sleepiness and self-reported academic performance scores. Irregular dinner-takers showed the longest after-school activities.

Conclusions:

Further attention should be given to both late and irregular dinner habits of pupils in terms of supporting their health. Further studies are needed to recommend suitable dinner timings for pupils by assessing optimal levels of variable lifestyle factors, including after-school activity.

The association between later eating rhythm and adiposity in children and adolescents: a systematic review and meta-analysis

CONTEXT

Childhood adiposity, an important predictor of adult chronic disease, has been rising dramatically. Later eating rhythm, termed night eating, is increasing in adults but rarely studied in younger ages.

OBJECTIVE

The objective of this study was to review the association between later eating rhythm and adiposity in children and adolescents. The aspects of later eating being considered included: energy intake (for evening main meal, evening snack, whole evening period, and around bedtime); timing (any food eaten at later timing); and meal frequency in the evening/night (evening main meal skipping, evening snack consumption).

DATA SOURCES

Five databases (the Cochrane Library, CINAHL, Embase, MEDLINE (via OVID), and Web of Science) were searched for eligible articles published prior to and including August 2020.

DATA EXTRACTION

Data extraction and quality assessment were conducted by 2 reviewers independently.

DATA ANALYSIS

Forty-seven studies were included, all of which were observational. Meta-analysis showed positive associations between both higher energy intake around bedtime (odds ratio [OR] 1.19, 95% CI 1.06, 1.33) and evening main meal skipping (OR 1.30, 95% CI 1.14, 1.48), and adiposity. There was evidence to suggest that consuming evening snacks reduced adiposity, but it was very weak (OR 0.80, 95% CI 0.62, 1.05). No association was seen between eating later and adiposity (OR 1.04, 95% CI 0.68, 1.61). In the narrative analysis, approximately half of the studies suggested that there was no association between later eating rhythm and adiposity, either as a whole or within exposure subsets.

CONCLUSION

The magnitude of the relationship between later eating rhythm and adiposity is very small, and may vary depending on which aspects of later eating rhythm are under consideration; however, the evidence for this conclusion is of very low certainty. Further research with a more consistent definition of "later timing", and longitudinal studies in different populations, may lead to different conclusions.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42019134187.