芬兰东部大学教授Andrew Agbaje领导的新研究对沿用42年的儿童"脂肪反弹"理论提出挑战[1]。该理论由法国研究员Marie Françoise Rolland-Cachera于1984年提出[1]，长期以来被用于解释儿童在6岁左右BMI上升的现象。
Agbaje的研究基于2410名2-19岁儿童的NHANES 2021-2023数据分析[1]，发现儿童BMI在2岁时平均为17.1 kg/m²，6岁时返回同一水平，但腰围身高比（WHtR）从0.54下降至更低水平，并在6岁之后从未恢复至初始水平[1]。
研究团队认为，传统BMI测量方法误将正常的肌肉和瘦体组织增长误读为脂肪反弹[1]。采用WHtR等更准确的测量方法后，体脂并未真正反弹，这一现象实际上代表的是儿童正常的生长过程而非肥胖警告信号[1]。WHtR与双能X射线吸收测定法（DEXA）测量脂肪质量的准确度约为90%[1]。
值得注意的是，长期饮食干预试验从7个月至20岁的跟踪研究未能改变BMI下降和上升的模式[1]，这进一步支持了该现象为正常生长的结论。Agbaje建议采用WHtR作为诊断儿童过量脂肪的通用临床工具[1]。该研究已在伊斯坦布尔欧洲肥胖研究大会上发表，并刊登于《营养学杂志》[1]。
Researchers have challenged a four-decade-old hypothesis about childhood weight patterns, suggesting that the widely accepted "adiposity rebound" theory may misinterpret normal growth as a warning sign of obesity. The theory, introduced by French researcher Marie Françoise Rolland-Cachera in 1984, posited that children's body mass index (BMI) rises around age six due to increased body fat [1]. However, new analysis indicates this rebound may actually reflect normal muscle and lean tissue development rather than fat accumulation [1].
The study, led by Andrew Agbaje from the University of Eastern Finland, analyzed data from 2,410 children aged 2 to 19 using the 2021-2023 National Health and Nutrition Examination Survey [1]. Researchers found that while average BMI returned to its two-year-old level of 17.1 kg/m² by age six, measurements using the waist-to-height ratio (WHtR)—a more precise indicator of body fat—told a different story [1]. WHtR declined from 0.54 and never rebounded to initial levels at age six or afterward, with the metric showing approximately 90% accuracy when compared to dual-energy X-ray absorptiometry (DEXA) scans [1]. Long-term dietary intervention trials spanning from seven months to age twenty similarly failed to alter the BMI pattern, suggesting the phenomenon reflects inherent developmental growth rather than reversible fat accumulation [1].
Agbaje presented the findings at the European Congress on Obesity in Istanbul and published them in the Journal of Nutrition, recommending that WHtR be adopted as a universal clinical tool for diagnosing excessive body fat in children rather than relying on traditional BMI measurements [1].