Researchers have identified two seemingly unrelated but strong predictors of obesity: having low self-esteem related to one's weight and keeping food visibly available around the house, outside the kitchen.
The Ohio State University study focused primarily on determining whether the home environment - architectural features and food storage and availability - was associated with obesity, but also measured a number of psychological factors. While architectural features had no relationship to obesity status, several food-related findings did.
People in the study who were obese kept more food visible throughout the house and generally ate less-healthy foods, such as sweets, than nonobese research participants. The two groups spent about the same amount of money on food and reported eating similar amounts of total calories, but nonobese participants spent less on fast food than did obese individuals.
"The amount of food in the homes was similar, but in the homes of obese individuals, food was distributed in more locations outside the kitchen," said Charles Emery, professor of psychology at Ohio State and lead author of the study. "That speaks to the environment being arranged in a way that may make it harder to avoid eating food. That has not been clearly documented before."
In addition, obese participants reported significantly lower self-esteem related to their body weight than did nonobese people. Obese participants also reported more symptoms of depression.
"Effects of the home environment and psychosocial factors haven't been examined together in previous studies," Emery said. "Most weight-loss interventions for children and people with eating disorders include a focus on self-esteem, but it's not standard for adult weight-loss programs. Self-esteem is important because when adults don't feel good about themselves, there may be less incentive for implementing behavioral changes in the home environment."
Though the statistical modeling identified predictors of obesity status, the predictors shouldn't be considered causes of weight problems, Emery said. "We're painting a detailed picture of the home environment that two different groups of people have created. Whether that environment contributed to obesity or obesity led to the environment, we don't know."
The study is published in the International Journal of Obesity.
Emery and colleagues recruited 100 participants between the ages of 20 and 78. Fifty were not obese, and the 50 obese participants had an average body mass index of 36.80 (a BMI of 30 indicates obesity). Researchers conducted a two-hour home visit with participants, interviewing them about food consumption, assessing the layout and food storage in the homes, and having participants complete self-report psychological questionnaires. They followed up two weeks later to evaluate participants' food purchases and physical activity.
The architectural assessment documented such details as the distance between favored spots in the house and food storage as well as stairs and doors that might be obstacles to food access.
Emery, also a professor of internal medicine and an investigator in Ohio State's Institute for Behavioral Medicine Research, noted that multiple metabolic and genetic factors contribute to obesity, but the home is a logical place to consider in efforts to improve health.
"I do think the home environment is a really important place to focus on since that's where most people spend a majority of their time," he said. "For interventions, we should be thinking about the home as a place to start helping people establish what we know to be healthier habits and behaviors."
Food is not the only issue affecting weight, either, Emery said. But changing eating habits is unlike many other behavior changes, such as quitting smoking or abstaining from alcohol.
Emery pointed out that in the study, obese participants reported greater concerns than nonobese participants about having access to enough food, but not for financial reasons. Obese participants also reported they were less able to avoid eating - whether they were hungry or not - when they were distressed or in settings where eating is socially acceptable.
"This may reflect a greater preoccupation with food, and that is also important. If food is something you're thinking about a lot, it potentially becomes a source of stress. And yet it's something hard not to think about," Emery said. "You can't just stop eating, but ideally you can change the way you eat and, to some degree, change the way you're thinking about eating."
Explore further: Eating habits, body fat related to differences in brain chemistry