Miriam study may help explain severe obesity

A newly published study from The Miriam Hospital’s Weight Control and Diabetes Research Center has found a physiological problem that may be to blame for severely obese people’s overeating: They may be much slower to respond to food cues and feel satisfied.
The study, led by Dale Bond, focused on habituation, or the idea that continual exposure to a specific food decreases one’s physical response to that food. The theory is that if one habituates, or adjusts, slowly to food cues, one is less likely to feel satisfied with that particular food and can consume more of it.
In the study, published online in Obesity Surgery, the research team compared how two groups – severely obese patients preparing for bariatric surgery, and a normal-weight control group – responded to repeated exposure to lemon juice.
The obese salivated at a consistent rate throughout the tastings, indicating that very little habituation occurred, whereas the normal-weight people salivated less and less as they consumed more of the lemon juice.
“The failure of bariatric surgery candidates to habituate suggests that satiation, or the feeling of fullness while eating, is impaired in this population,” Bond said in a news release. “This could play a role in the inability of some severely obese individuals to regulate or control the amount of food that they eat during a meal.”
Bond added that the study findings suggest it may be worthwhile to look at habituation problems as a possible reason why some patients who have undergone bariatric surgery continue to engage in problematic behaviors, such as binge eating, and regain weight.
“Bariatric surgery has been referred to as ‘behavioral surgery,’ given the importance of eating behavior in postoperative outcomes,” he said. “Habituation may be a valuable tool for enhancing our understanding of eating regulation in severely obese individuals and how it is impacted by bariatric surgery.”
Previous research had compared habituation among individuals with mild obesity and those with normal weight, with similar results.
Bond is also an assistant professor of psychiatry at the Warren Alpert Medical School of Brown University, and the research was funded by grants from the school’s Center for Excellence in Women’s Health and the American Diabetes Association.
The Miriam Hospital, in Providence, is part of the Lifespan health system and is affiliated with the Warren Alpert Medical School of Brown University. For more information, go to www.miriamhospital.org.