The role of hunger state and dieting history in neural response to food cues: An event-related potential study.

A history of dieting to lose weight has been shown to be a robust predictor of future weight gain. A potential factor in propensity towards weight gain is the nature of people's reactions to the abundance of highly palatable food cues in the environment. Event Related Potentials (ERPs) have revealed differences in how the brain processes food cues between obese and normal weight individuals, as well as between restrained and unrestrained eaters. However, comparisons by weight status are not informative regarding whether differences predate or follow weight gain in obese individuals and restrained eating has not consistently been found to predict future weight gain. The present study compared ERP responses to food cues in non-obese historic dieters (HDs) to non-obese never dieters (NDs). HDs showed a blunted N1 component relative to NDs overall, and delayed N1 and P2 components compared to NDs in the hungry state, suggesting that early, perceptual processing of food cues differs between these groups, especially when food-deprived. HDs also showed a more hunger-dependent sustained ERP (LPP) compared to NDs. Future research should test ERP-based food cue responsivity as a mediator between dieting history and future weight gain to better identify those most at risk for weight gain as well as the nature of their vulnerability.

Childhood body mass index in adolescent-onset anorexia nervosa.

OBJECTIVE: Although weight history is relevant in predicting eating disorder symptom severity, little is known about its role in the etiology of anorexia nervosa (AN). This study aimed to determine whether BMI or BMI trajectory differed between individuals who later developed adolescent-onset AN and a comparison group of HCs between school grades 1 through 6. METHOD: This study was based on longitudinal data that identified 51 adolescents with AN and 51 matched HCs. Cases were identified through community screening in Sweden and included individuals born in 1969 through 1977. Measured weights and heights were retrieved and BMIs and weight trajectories of the AN and HC groups were compared using growth curve analysis. Main outcome measures included measured BMI and BMI trajectories from grades 1-6. Secondary outcomes examined included ponderal index at birth and maternal body weight. RESULTS: Individuals who later developed AN had higher BMIs than HCs between grades 1 and 6, by an average of 1.42 BMI-units. There was no difference in rate of weight gain between groups. Ponderal index at birth was higher for the AN as compared with HC group. Maternal weight did not differ significantly between groups. DISCUSSION: These findings, combined with those previously reported on the premorbid BMIs of those with bulimia nervosa, suggest that a predisposition toward elevated premorbid BMIs during childhood characterizes those who later develop anorexia or bulimia nervosa. These findings are consistent with a transdiagnostic perspective and suggest shared risk factors for AN and obesity. © 2016 Wiley Periodicals, Inc. (Int J Eat Disord 2016; 49:1002-1009).

Weight suppression and body mass index interact to predict long-term weight outcomes in adolescent-onset anorexia nervosa.

UNLABELLED: Research on anorexia nervosa (AN) has emphasized the importance of low absolute body weight, but emerging research suggests the importance of also considering low body weight relative to an individual's highest premorbid weight (weight suppression; WS). OBJECTIVE: We investigated whether body mass index and WS at lowest weight (BMI-LW and WS-LW) among adolescents with AN predicted BMI at 6-, 10-, or 18-year follow-up, duration of AN, or total eating disorder duration, including time during which criteria were met for bulimia nervosa or eating disorder not otherwise specified. METHOD: Forty-seven cases of AN identified through community screening in Sweden were included. Weight and height data were collected from medical records, school nurse charts, and study follow-up assessments. RESULTS: Higher WS-LW was associated with higher BMI at 6-year and 10-year follow-up, and this effect was strongest among those with the lowest BMI-LW values. BMI-LW and WS-LW were positively associated with BMI at 18-year follow-up, but there was no significant interaction. There was no significant association between WS-LW and AN duration or eating disorder duration, although eating disorder duration was longer among those with higher BMI-LW, controlling for WS-LW. CONCLUSIONS: Absolute and relative weight status interact to predict weight outcomes in AN over the long term. RESULTS suggest that BMI and WS may be more relevant to the prediction of long-term weight outcomes than to the persistence of other eating disorder symptoms.