Murray Helen B, Tabri Nassim, Thomas Jennifer J, Herzog David B, Franko Debra L, Eddy Kamryn T
Eating Disorders Clinical and Research Program, Massachusetts General Hospital, 2 Longfellow Place, Suite 200, Boston, MA, 02114.
Psychology Department, Drexel University, 3141 Chestnut Street, Stratton Hall 119, Philadelphia, PA, 19104.
Int J Eat Disord. 2017 Jul;50(7):739-747. doi: 10.1002/eat.22690. Epub 2017 Feb 11.
For some, fat phobia or fear of uncontrollable weight gain is diagnostic of eating disorders, often inhibiting treatment engagement and predicting symptom relapse. Prior research has reported weight changes at infrequent or long intervals, but rate, shape, and magnitude of long-term changes remain unknown. Our study examined 22-year longitudinal trajectories of body mass index (BMI) in women with anorexia nervosa (AN) and bulimia nervosa (BN).
Participants were followed over 10 years (N = 225) and at 22-year follow-up (N = 175). Using latent growth curves, we examined: (1) shape and rate of intra-individual BMI change over 10 years; (2) predictors of BMI change over 10 years, (3) 22-year BMI outcomes; and (4) BMI changes over 10 years as predictors of 22-year BMI.
The best-fitting model captured overall intra-individual rates of BMI change in three intervals, showing moderate rate of BMI increase from intake to year 2, modest increase from year 2 to 5, and plateau from year 5 to 10. At 22 years, 14% were underweight, 69% were normal weight, and only 17% were overweight or obese. Greater increases from intake to year 2 predicted higher BMI at 22 years (β = 0.43, p < 0.01) and were predicted by intake diagnosis of AN-restricting (β = 0.31, p < 0.01) or AN-binge eating/purging (β = 0.29, p < 0.01).
BMI increased most rapidly during earlier years of the study for those with lower weight at study intake (i. e., AN) and plateaued over time, settling in the normal range for most. Psychoeducation about expected BMI trajectory may challenge patients' long-term fat phobic predictions.
对一些人来说，恐胖症或对无法控制的体重增加的恐惧是饮食失调的诊断依据，这常常会抑制治疗参与度并预示症状复发。先前的研究报告了不频繁或长时间间隔的体重变化，但长期变化的速率、形态和幅度仍不清楚。我们的研究调查了神经性厌食症（AN）和神经性贪食症（BN）女性患者22年的体重指数（BMI）纵向轨迹。
对参与者进行了10年的随访（N = 225），并在22年的随访时（N = 175）进行了观察。使用潜在增长曲线，我们研究了：（1）个体内BMI在10年内变化的形态和速率；（2）10年内BMI变化的预测因素；（3）22年时的BMI结果；以及（4）10年内的BMI变化作为22年时BMI的预测因素。
拟合度最佳的模型捕捉到了个体内BMI在三个时间段的总体变化速率，显示从入组到第2年BMI适度增加，从第2年到第5年适度增加，从第5年到第10年趋于平稳。在22年时，14%的人体重过轻，69%的人体重正常，只有17%的人体重超重或肥胖。从入组到第2年增加幅度越大，预示着22年时的BMI越高（β = 0.43，p < 0.01），并且由限制型AN（β = 0.31，p < 0.01）或暴饮暴食/清除型AN（β = 0.29，p < 0.01）的入组诊断所预测。
在研究早期，对于入组时体重较低的人（即AN患者），BMI增加最为迅速，随着时间推移趋于平稳，大多数人稳定在正常范围内。关于预期BMI轨迹的心理教育可能会挑战患者长期的恐胖预测。
