Department of Anthropology, Baylor University, Waco, TX, USA.
Child and Brain Development Program, CIFAR, Toronto, Ontario, Canada.
J Nutr. 2021 Mar 11;151(3):695-704. doi: 10.1093/jn/nxaa361.
Childhood overweight and obesity (OW/OB) is increasingly centered in low- and middle-income countries (LMICs) as rural populations experience market integration and lifeway change. Most explanatory studies have relied on imprecise estimates of children's energy expenditure, restricting understanding of the relative effects of changes in diet and energy expenditure on the development of OW/OB in transitioning contexts.
This study used gold-standard measurements of children's energy expenditure to investigate the changes that underlie OW/OB and the nutrition/epidemiologic transition.
Cross-sectional data were collected from "rural" (n = 43) Shuar forager-horticulturalist children and their "peri-urban" (n = 34) Shuar counterparts (age 4-12 y) in Amazonian Ecuador. Doubly labeled water measurements of total energy expenditure (TEE; kcal/d), respirometry measurements of resting energy expenditure (REE; kcal/d), and measures of diet, physical activity, immune activity, and market integration were analyzed primarily using regression models.
Peri-urban children had higher body fat percentage (+8.1%, P < 0.001), greater consumption of market-acquired foods (multiple P < 0.001), lower concentrations of immune activity biomarkers (multiple P < 0.05), and lower REE (-108 kcal/d, P = 0.002) than rural children. Despite these differences, peri-urban children's TEE was indistinguishable from that of rural children (P = 0.499). Moreover, although sample-wide IgG concentrations and household incomes predicted REE (both P < 0.05), no examined household, immune activity, or physical activity measures were related to children's overall TEE (all P > 0.09). Diet and energy expenditure associations with adiposity demonstrate that only reported consumption of market-acquired "protein" and "carbohydrate" foods predicted children's body fat levels (multiple P < 0.05).
Despite underlying patterns in REE, Shuar children's TEE is not reliably related to market integration and-unlike dietary measures-does not predict adiposity. These findings suggest a leading role of changing dietary intake in transitions to OW/OB in LMICs.
随着农村人口经历市场一体化和生活方式的改变，儿童超重和肥胖（OW/OB）日益成为低收入和中等收入国家（LMICs）的中心问题。大多数解释性研究依赖于对儿童能量消耗的不精确估计，这限制了对饮食和能量消耗变化对转型背景下 OW/OB 发展的相对影响的理解。
本研究使用儿童能量消耗的金标准测量方法，研究 OW/OB 和营养/流行病学转变的基础变化。
从厄瓜多尔亚马逊地区的农村（n=43）Shuar 觅食-园艺儿童及其城市周边（n=34）Shuar 同龄人（4-12 岁）中收集横断面数据。使用双标记水测量总能量消耗（TEE；千卡/天），呼吸计测量静息能量消耗（REE；千卡/天），并测量饮食、体力活动、免疫活性和市场一体化。主要使用回归模型进行分析。
城市周边儿童的体脂百分比更高（+8.1%，P<0.001），消费更多的市场获得的食物（多种 P<0.001），免疫活性生物标志物浓度更低（多种 P<0.05），REE 更低（-108 千卡/天，P=0.002）比农村儿童。尽管存在这些差异，但城市周边儿童的 TEE 与农村儿童无法区分（P=0.499）。此外，尽管 IgG 浓度和家庭收入整体预测 REE（均 P<0.05），但没有检查家庭、免疫或体力活动措施与儿童的整体 TEE 相关（均 P>0.09）。饮食和能量消耗与肥胖的关联表明，只有报告的市场获得的“蛋白质”和“碳水化合物”食物的消耗预测了儿童的体脂水平（多种 P<0.05）。
尽管 REE 存在潜在模式，但 Shuar 儿童的 TEE 与市场一体化没有可靠的关系，与饮食措施不同，也不能预测肥胖。这些发现表明，在 LMICs 向 OW/OB 过渡中，改变饮食摄入起着主导作用。
