Recent research suggests that the psychological consequences of being in a disadvantaged position in society may stimulate appetite and increase eating regardless of one's ability to access healthier foods. These findings, out from Nanyang Technological University in Singapore and the Singapore Institute for Clinical Sciences, add a new dimension to previous findings suggesting that the increased risk for obesity among people who are poorer and socioeconomically disadvantaged is due primarily to economic barriers that prevent access to healthier foods and other unhealthy behaviors associated with poverty.

These intriguing findings, presented by Dr. Bobby Cheon at the annual meeting of the Society for the Study of Ingestive Behavior this week, involved making research participants feel like they have inadequate socioeconomic resources compared to other people and measuring the effects on eating behaviors. Participants in the study were led to make comparisons of financial, economic, and social status resources (e.g., having a respected position in society) with others who were either much better off or much worse off than them. This approach of experimentally manipulating whether people perceive themselves as having sufficient or inadequate socioeconomic standing compared to others allowed the researchers to directly test whether the mere perception of socioeconomic disadvantage influences food preferences and eating behaviors.

Across multiple studies, the researchers found that participants who were led to feel they had fewer resources and opportunities compared to others ate more calories from snacks and meals offered during the experiment, served themselves larger portion sizes of foods, and showed increased ability to detect differences in calories between beverages. Participants who experienced feelings of socioeconomic disadvantage also had elevated levels of ghrelin -- often referred to as the "hunger hormone" -- providing a biological explanation for the desire to eat more under these conditions.

"If feelings of deprivation and inadequacy produced by perceived socioeconomic inequality can stimulate appetite and food intake, then it's possible that feeling that important needs in one's life have been satisfied may produce the opposite effect of reducing excessive food intake," said Cheon. To test this, research participants were assigned to complete a daily gratitude journal for 2 weeks, in which they listed things that they were grateful for each day. Compared to a control group that wrote about events that occurred each day, male participants in the gratitude journal group showed a reduction in desired portions of a variety of foods.

Although inadequate access to healthy foods is often blamed for obesity in populations with lower socioeconomic status, this research shows that the psychological consequences of social and economic inequality are also detrimental to health. The research team plans to continue to test methods, like heightening gratitude, to psychologically protect people from engaging in potentially unhealthy eating behaviors in response to perceived socioeconomic inequality and insecurities.