ISSN 0439-755X
CN 11-1911/B

Acta Psychologica Sinica ›› 2020, Vol. 52 ›› Issue (10): 1224-1236.doi: 10.3724/SP.J.1041.2020.01224

• Reports of Empirical Studies • Previous Articles     Next Articles

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

LUO Yijun1,2, NIU Gengfeng3, CHEN Hong1,2()   

  1. 1School of Psychology, Southwest University, Chongqing 400715, China
    2Key Laboratory of Cognition and Personality (Ministry of Education), Southwest University, Chongqing 400715, China
    3School of Psychology, Central China Normal University, Wuhan 430079, China
  • Received:2020-02-19 Published:2020-10-25 Online:2020-08-24
  • Contact: CHEN Hong E-mail:chenhg@swu.edu.cn
  • Supported by:
    National Natural Science Foundation of China(31771237);Innovation team project of special fund for basic scientific research business expenses of Central University(swu1709106);Innovation team project of special fund for basic scientific research business expenses of Central University(SWU1809355)

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 in the absence of hunger state, 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, for 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 group. 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.

Key words: life history theory, environmental unpredictability, overeating, moderated mediation model, COVID-19