Review: emotions and eating in adult obesity

Nutrition Research Newsletter, June, 1989 by R.M. Ganley

In 1957, the last major review of emotions and eating in obesity concluded that obese people overeat because eating reduces their anxiety levels. In the two decades since then, many clinical and experimental studies have been completed, and a more complex picture has emerged. Most of the nonexperimental studies have involved self-report, structured interviews, or questionnaires administered to obese adults seeking weight-loss treatment. Subjects with varying degrees of obesity have been studied, and the majority have reported eating in response to negative emotions (anger, depression, boredom, anxiety, loneliness) or stressful life events.
Emotional eating in obese people seeking weight-loss treatment tends to be episodic and may not occur on a regular basis. It has been reported in people at all socioeconomic levels and in both sexes, although the findings are better established in women.
Some studies have included normal-weight control groups, and all of these have found differences between obese and normal subjects in patterns of emotional eating. A few studies have been conducted in obese people who were not seeking weight-loss treatment, and they support the conclusion that emotional eating is common in the obese. Therefore, the relationship between emotions and eating does not appear to be limited to the segment of the obese population that seeks treatment.
In addition to its episodic nature, emotional eating in the obese has been shown to have several other characteristic features. It is shrouded in secrecy, often occurs in the absence of perceived hunger, is associated with different emotions in different individuals, often produces affect reduction (a calm, sleepy, or sluggish feeling), and typically involves a favorite high-calorie or high-carbohydrate food.

The reviewer observes that some of these characteristics make emotional eating difficult to study. For instance, studies of public eating may not detect it because of its secretive nature, and short-term dietary records may not detect infrequent binges.
Experimental studies of emotional eating have generally placed obese and normal subjects (usually college students) in situations designed to produce anxiety or arousal, and then measured their consumption of available food. At first glance, the results of these studies appear equivocal; only 5 of 11 found increased eating in response to arousal. It is noteworthy, however, that all four studies using crackers (a food not typically chosen for emotional eating binges) had negative results, while five of seven using more palatable, higher-calorie foods (cookies, candy, nuts, ice cream) found higher levels of eating in overweight than normal-weight groups.
The reviewer concludes that "overall, the laboratory studies using higher palatability foods support the hypothesis that overweight, compared with normal-weight, individuals increase their eating in response to emotional distress." Limitations of these studies include the near-uniform age and socioeconomic status of the students who were used as subjects and their relatively mild obesity, as well as the use of relatively mild, short-term stressors.

In conclusion, the reviewer states that emotions appear to influence eating by obese subjects, but only if individual variability and the special qualities of emotional eating are considered. The available data suggest that a major determinant of emotional eating is its ability to reduce negative emotions.