Restrictive eating in anorexia nervosa: Examining maintenance and consequences in the natural environment.

OBJECTIVE: This study examined negative and positive affect in relation to restrictive eating episodes (i.e., meals/snacks perceived as restrictive) and whether restrictive eating was associated with likelihood of subsequent eating disorder behaviors (i.e., additional restrictive eating, binge eating, vomiting, laxative use, weighing, exercising, meal skipping, drinking fluids to curb appetite, body checking).
METHOD: Women with anorexia nervosa (N = 118) completed a 2-week ecological momentary assessment protocol.
RESULTS: For both restrictive and nonrestrictive eating, negative affect significantly increased from prebehavior to the time of the behavior but remained stable thereafter, while positive affect remained stable from prebehavior to the time of the behavior but decreased significantly thereafter. Across time, negative affect was significantly lower and positive affect was significantly greater in restrictive than nonrestrictive episodes. Engagement in restrictive eating was associated with an increased likelihood of subsequent restrictive eating, laxative use, and body checking, but not other behaviors. Engagement in nonrestrictive eating was associated with a decreased likelihood of subsequent restrictive eating, binge eating, vomiting, laxative use, weighing, meal skipping, drinking fluids to curb appetite, and body checking. DISCUSSION: Despite similar patterns of affect across eating episodes over time, results suggest affect may be involved in the maintenance of restrictive eating in anorexia nervosa since restrictive episodes were associated with lower negative and greater positive affect across time compared to nonrestrictive episodes. Further, while restrictive episodes increased the likelihood of only three subsequent eating disorder behaviors, nonrestrictive episodes were protective since they decreased likelihood of all but one behavior.