A systematic review of temporal body weight and dietary intake patterns in adults: implications on future public health nutrition interventions to promote healthy weight

Purpose: The global prevalence of overweight remains high; effective strategies that consider patterns of body weight changes to identify periods when adults are susceptible to weight gain are warranted. This systematic review aimed to investigate body weight patterns, and how they were associated with dietary intake and/or dietary behaviours (Prospero CRD42020161977). Methods: Systematic literature search was conducted in the Medline, Embase, and CINAHL databases until November 2020. Observational studies in adults (18 years and over) that reported at least two measurements of weight and dietary intake in a year were included. Risk of bias was conducted using the Evidence Analysis Library by the Academy of Nutrition and Dietetics tool. This review included 16 unique studies after title, abstract, and full-text screening, and findings were narratively synthesised. Results: Of the six studies conducted in the farming populations, five were conducted in countries with two seasons (dry vs. rainy seasons) and all studies observed higher body weight during the dry season (up to 3.1 kg difference between seasons). The remaining study was conducted in a sub-tropical country and did not observe temporal weight patterns. Higher dietary intake was also reported during the dry season in the tropical countries. In non-farming populations (n = 10), temporal patterns were also seen, where higher body weight and adiposity was observed during colder seasons (autumn and winter). However, the opposite was found in a study conducted in Iran, where higher weight was seen in summer. Concurrent with higher body weight, higher energy, fat, carbohydrate and soda consumption, and lower fiber and vegetable intake were observed. Conclusion: Temporal weight and dietary patterns exist, and they were country- and context-specific; these patterns were also related to factors such as activity levels, seasons and occupation. Future interventions should consider temporal patterns in the design and delivery of timely and tailored dietary interventions to promote optimal body weight. Refereed/Peer-reviewed