Early life environmental unpredictability and overeating: Based on life history theory

Abstract

According to life history theory, organisms face necessary trade-offs in allocating limited energy and resources between somatic effort and reproductive effort How an individual allocates resources to cope with survival and reproductive tasks reflects their life history strategies In unpredictable environments, individuals tend to invest more in reproductive efforts and prioritize immediate payoffs because the future is uncertain, and the delayed benefits may not be available later Food may be considered an immediate reward and overeating may more likely occur among people living in unpredictable environments Our research investigated how early life environmental unpredictability affects overeating and the underlying mechanism between the association Study 1 recruited 91 adolescent participants and utilized the Eating in the Absence of Hunger protocol (EAH) Participants were randomly assigned either to the “hunger” or “absence of hunger” groups Both groups completed a food portion choice task Participants were presented with photographs of 36 food types (18 high-calorie and 18 low-calorie), where participants chose their desired food portion on each picture from 0 (none) to 4 (four portions) Results indicated that the hunger state could moderate the effects of early life environmental unpredictability on overeating Specifically, (a)in hunger state, environmental unpredictability was not associated with selected high-calorie/unhealthy food portion, while participants living in high environmental unpredictability selected more high-calorie/unhealthy food portion than those living in low environmental unpredictability, i e , overeating;(b)in hunger state, participants living in high environmental unpredictability selected less low-calorie/healthy food portion than those living in low environmental unpredictability, while in the absence of hunger state, environmental unpredictability was not associated with selected low-calorie/healthy food portion Hence, our results, on the one hand, supported the initial hypothesis that early life environmental unpredictability could promote overeating in the absence of hunger state On the other hand, our findings demonstrated that individuals in the hunger state would be more impulsive, selecting less healthy food Study 2 examined differences in overeating between participants with high and low perceived death threat states The former group was comprised of 301 community residents from Wuhan City, the epicenter of the Coronavirus Disease 2019 (COVID-19) outbreak The latter group was comprised of 179 community residents from the 42 other cities in China Participants completed questionnaires regarding early life environmental unpredictability, fast life history strategy (Mini-K), overeating, perceived death threat, and social support Results indicated that early life environmental unpredictability may affect overeating through the mediating role of fast life history strategies Moreover, perceived death threat and social support may moderate the path between fast life history strategies and overeating Evidently, participants with both high and low death threats, fast life history strategies were positively associated with overeating;however, the effect was smaller for the latter grouping For individuals with high social support, fast life history strategies were not associated with overeating;while for individuals with low social support, fast life history strategies were positively associated with overeating Findings indicated that environmental unpredictability in early life was positively associated with overeating through fast life history strategies Additionally, this effect intensifies when the current environment is life-threatening;while the effect would be buffered for individuals with high social support Findings provided evidence for the prevention and intervention of healthy eating promotion in the context of COVID-19 © 2020, Science Press All rights reserved