Lookup NU author(s): Professor Daniel Nettle,
Dr Clare Andrews,
Professor Melissa Bateson
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License (CC BY-NC 4.0).
Integrative explanations of why obesity is more prevalent in some sectors of the human populationthan others are lacking. Here, we outline and evaluate one candidate explanation, the insurancehypothesis (IH). The IH is rooted in adaptive evolutionary thinking: the function of storing fat is toprovide a buffer against shortfall in the food supply. Thus, individuals should store more fat when theyreceive cues that access to food is uncertain. Applied to humans, this implies that an importantproximate driver of obesity should be food insecurity rather than food abundance per se. We integrateseveral distinct lines of theory and evidence that bear on this hypothesis. We present a theoreticalmodel that shows it is optimal to store more fat when food access is uncertain, and we review theexperimental literature from non-human animals showing that fat reserves increase when access tofood is restricted. We provide a meta-analysis of 125 epidemiological studies of the associationbetween perceived food insecurity and high body weight in humans. There is a robust positiveassociation, but it is restricted to adult women in high-income countries. We explore why this couldbe in light of the IH and our theoretical model. We conclude that whilst the IH alone cannot explainthe distribution of obesity in the human population, it may represent a very important component ofa pluralistic explanation. We also discuss insights it may offer into the developmental origins ofobesity, dieting-induced weight gain, and Anorexia Nervosa.
Author(s): Nettle D, Andrews C, Bateson M
Publication type: Article
Publication status: Published
Journal: Behavioral and Brain Sciences
Online publication date: 28/07/2016
Acceptance date: 11/07/2016
Date deposited: 11/07/2016
ISSN (print): 0140-525X
ISSN (electronic): 1469-1825
Publisher: Cambridge University Press
Altmetrics provided by Altmetric