Center for Childhood Obesity Research, The Pennsylvania State University, 129 Noll Laboratory, University Park, PA, 16802, USA.
Department of Exercise and Nutrition Sciences, University at Buffalo, 12 Sherman Hall, Buffalo, NY, 14214, USA.
BMC Public Health. 2018 Nov 22;18(1):1285. doi: 10.1186/s12889-018-6206-y.
Peak bone mass accrual occurs during adolescence, a time when dieting and related eating behaviors are common. Impaired bone mineral accrual is a known consequence of eating disorders in adolescents, but the effects of subclinical dieting behaviors on bone mineral content (BMC) have not been described in this age group. The goal of this analysis was to determine whether dieting behavior in preadolescence and adolescence is associated with bone mineral accrual in adolescent girls.
Non-Hispanic white girls (n = 139) were followed in a longitudinal cohort study. BMC was assessed at ages 9 and 15y. Dieting to lose weight was reported every 2 years, and dietary restraint and disinhibition, eating attitudes, weight concerns, and body esteem were assessed at age 11y. Girls were classified as "early dieters" if they first dieted by age 11y (31.7%), "adolescent dieters" if they first dieted after 11y (46.8%), or non-dieters if they did not report dieting by 15 y (21.6%). The effect of dieting related variables on BMC at 15y and change in BMC from 9 to 15y was assessed using linear regression, controlling for height, weight, BMI, physical activity, and pubertal status.
Girls who first reported dieting to lose weight by age 11y had a 4.2% lower bone mineral accrual across adolescence (p = 0.02) and 3.1% lower BMC at age 15y (p = 0.005) than girls who first reported dieting after 11y or not at all. Number of weight control behaviors used, dietary restraint, and weight concerns were also negatively associated with BMC (p < 0.05).
Dieting behavior in preadolescence is associated with reduced bone mineral accrual. Strategies to promote optimal bone development should include prevention of dieting.
Clinicaltrials.gov NCT03342430, November 17, 2017. Retrospectively registered.
峰值骨量的积累发生在青春期，这是节食和相关的饮食行为很常见的时期。在青少年中，饮食失调会导致骨矿物质积累受损，这是已知的后果，但亚临床节食行为对骨矿物质含量（BMC）的影响在这个年龄段尚未描述。本分析的目的是确定青春期前和青春期的节食行为是否与少女的骨矿物质积累有关。
对非西班牙裔白人女孩（n=139）进行纵向队列研究。在 9 岁和 15 岁时评估 BMC。每 2 年报告一次减肥节食，在 11 岁时评估饮食限制和抑制、饮食态度、体重担忧和身体自尊。如果女孩在 11 岁之前首次节食（31.7%），则将其归类为“早期节食者”；如果女孩在 11 岁之后首次节食（46.8%），则将其归类为“青春期节食者”；如果女孩在 15 岁时未报告节食，则将其归类为“非节食者”（21.6%）。使用线性回归评估节食相关变量对 15 岁时 BMC 和 9 至 15 岁时 BMC 变化的影响，控制身高、体重、BMI、体力活动和青春期状态。
11 岁时首次报告为减肥而节食的女孩在整个青春期的骨矿物质积累减少了 4.2%（p=0.02），15 岁时的 BMC 减少了 3.1%（p=0.005），而首次在 11 岁后或从未报告过节食的女孩。使用的体重控制行为的数量、饮食限制和体重担忧也与 BMC 呈负相关（p<0.05）。
青春期前的节食行为与骨矿物质积累减少有关。促进最佳骨骼发育的策略应包括预防节食。
Clinicaltrials.gov NCT03342430，2017 年 11 月 17 日。回顾性注册。
