The study, led by Heather Niemeier, Ph.D., of The Miriam Hospital's Weight Control & Diabetes Research Centre and The Warren Alpert Medical School of Brown University, found that dieters who have the tendency to eat in response to external factors, such as at festive celebrations, have fewer problems with their weight loss than those who eat in response to emotions (internal factors).
"We found that the more people report eating in response to thoughts and feelings, such as, 'when I feel lonely, I console myself by eating,' the less weight they lost in a behavioural weight loss program," Niemeier said. "In addition, amongst successful weight losers, those who report emotional eating are more likely to regain," she said.
The study included two groups of individuals. The first group consisted of 286 overweight men and women who were currently participating in a behavioural weight loss program. The second group included 3,345 members of the National Weight Control Registry (NWCR), an ongoing study of adults who had lost at least 30 pounds and kept it off for at least one year.
"Participants in behavioural weight loss programs lose an average of 10 percent of their body weight and these losses are associated with significant health benefits. Unfortunately, the majority of participants return to their baseline weight within three to five years," Niemeier said. In the study, researchers analysed individual's responses to a questionnaire widely used in obesity research called the Eating Inventory, a clinical tool designed to assess three aspects of eating behaviour in individuals - cognitive restraint, hunger, and disinhibition.
The analysis of the study found that the components within the disinhibition scale could be grouped into two distinct factors - external and internal disinhibition. External disinhibition described experiences that were external to the individual such as, "When I am with someone who is overeating, I usually overeat, too" and "I usually eat too much at social occasions, like parties and picnics".
Internal disinhibition referred to eating in response to thoughts and feelings that were internal to the individual and included emotional eating such as, "When I feel lonely, I console myself by eating" and "While on a diet, if I eat a food that is not allowed, I often splurge and eat other high calorie foods". The finding revealed that in both groups of participants, internal disinhibition was a significant predictor of weight over time.
For the participants in the weight loss program, the higher the level of internal disinhibition, the less weight an individual lost over time. The same was true for maintainers in NWCR in that internal disinhibition predicted weight regain over the first year of registry membership. The study also found that emotional eating was associated with weight regain in successful losers.
"Interestingly, external disinhibition did not predict weight loss or regain in either sample at any time," Niemeier said. "Modifying our treatments to address these triggers for unhealthy eating and help patients learn alternative strategies could improve their ability to maintain weight loss behaviours, even in the face of affective and cognitive difficulties," she added.
The study is published in Obesity.