Food insecurity of fatness: from evolutionary ecology to social science
Jul 8, 2019
auto_awesome
This podcast explores the evolutionary, biological, and social science questions related to food insecurity and fatness. It debunks the 'No Breaks Hypothesis', discusses the mismatch between evolutionary motivations and social science understanding of obesity, and explores the correlation between food insecurity and obesity. It also explores the adaptive decision-making process of how much to eat for survival, presents an experiment on starlings' body mass regulation, and discusses the impact of food insecurity on foraging behavior in birds.
Evolutionary thinking challenges the belief that humans have no limits on consuming sugar and fat, as cultural practices and appetite limiters for sugar and fat exist.
Food insecurity and obesity coexist, with studies showing higher rates of obesity among lower-income populations and the importance of social factors and economic disparities.
A behavioral ecological model suggests that weight regulation is influenced by factors such as food availability and energy expenditure, with individuals in food-insecure environments overconsuming to buffer periods of scarcity.
Deep dives
The Evolutionary Perspective on Human Obesity
Evolutionary thinking challenges the idea that humans have no limits on consuming sugar and fat, leading to obesity. Evidence shows that there are appetite limiters for sugar and fat, as seen in cultural practices like pre-marriage feeding rituals. The no-break hypothesis does not take into account our body's homeostatic mechanisms that regulate caloric intake. People have the ability to maintain a stable weight, even with varying levels of physical activity. The idea that humans lack evolved mechanisms to limit sugar and fat intake is flawed.
Food Insecurity and its Impact on Weight
Food insecurity and obesity coexist in the same individuals. Studies consistently show that food insecurity is associated with higher odds of being overweight or obese. This association is particularly significant among women. Contrary to the 'more money leads to more obesity' hypothesis, data shows that rates of obesity are higher among lower-income populations. Income inequality also correlates with higher rates of obesity. The mismatch hypothesis alone cannot explain why obesity is more prevalent in certain social groups and populations. Other factors, such as the social distribution of experience and economic disparities, play a significant role.
A Behavioral Ecological Model of Weight Regulation
A behavioral ecological model suggests that weight regulation is influenced by factors such as the probability of finding food and the costs of carrying extra weight. Animals, including humans, regulate their body weight within certain limits to maximize long-term survival. The model predicts that in food-insecure environments, individuals should overconsume when food is available to buffer periods of food scarcity. Studies show that higher food insecurity leads to weight gain, contradicting the assumption that individuals eat more overall. The model highlights the importance of considering energy expenditure in addition to food intake when understanding weight regulation.
Microstructure of Foraging Behavior in Food-Insecure Birds
In examining the microstructure of foraging behavior in birds experiencing food insecurity, interesting findings emerge. Birds experiencing higher food insecurity forage more intensely and reach their maximum mass earlier in the day. However, they do not consume more food overall, indicating that food intake decreases even as foraging efforts increase. This challenges the assumption that increased food insecurity leads to increased food consumption. The results suggest the possibility of reduced energy expenditure or changes in other aspects of activity in response to food insecurity.
Exploring the Pathways of Food Insecurity and Weight Gain
Further research is needed to understand the complex relationships between food insecurity, depression, physical activity, and weight gain. Analyzing comprehensive data from surveys like the National Health and Nutrition Examination Survey (NHANES) can provide insights into the mediators of weight gain in food-insecure populations. By examining factors such as macro-nutrient composition, calorie intake, physical activity levels, and other related variables, a more complete understanding of the pathways between food insecurity and weight gain can be achieved.
