Trend of adults’ occupational physical activity levels and nutritional status over four decades in Brazil

Abstract Objective: to evaluate the trend of adults’ (≥ 20 years) occupational physical activity levels and nutritional status in Brazilian national surveys carried out over four decades. Methods: the declared data regarding main occupation was stratified in three physical activity levels (light, moderate, and heavy) according to the classifications in force when the surveys were conducted. The nutritional status was determined according to the World Health Organization classification based on the body mass index (BMI, kg.m-2) as underweight (BMI < 18.5), normal (18,5 ≤ IMC < 25) and overweight (BMI ≥ 25). All estimates were calculated using the sampling weights from the surveys. Results: the population with declared occupation increased in the period, with greater moderate physical activity levels in the 1970’s and shifting to light in the 2000’s. The prevalence of underweight decreased and of overweight increased substantially for all physical activity levels. Overweight ranged from 27.6 to 49.7% in light levels and from 12.7 to 43.3% in heavy levels. Conclusions: despite the limitations of the study (the physical activity levels were estimated by declared occupation and did not consider the development/modification of labor processes), we concluded that workers in Brazil present a positive energy balance regardless of their occupational physical activity levels.

摘要
目的：评估近四十年来巴西全国性调查中20岁及以上成年人的职业体力活动水平与营养状况的变化趋势。
方法：根据各调查开展时现行的分类标准，将受试者报告的主要职业划分为轻度、中度、重度三类体力活动水平。营养状况依据世界卫生组织（World Health Organization，WHO）基于身体质量指数（Body Mass Index，BMI，单位：kg·m⁻²）的分类标准判定，分为体重不足（BMI＜18.5）、体重正常（18.5≤BMI＜25）与超重（BMI≥25）三类。所有统计估算均采用调查的抽样权重进行计算。
结果：研究期间，报告职业的人群占比有所上升；1970年代职业体力活动以中度水平为主，至2000年代则转向轻度水平。各体力活动水平组的体重不足患病率均有所下降，而超重患病率则显著升高。轻度体力活动组的超重患病率介于27.6%至49.7%之间，重度体力活动组则介于12.7%至43.3%之间。
结论：尽管本研究存在局限性（职业体力活动水平通过自我报告的职业估算，未考虑劳动过程的发展与调整），但研究表明，无论职业体力活动水平如何，巴西劳动者均呈现正向能量平衡状态。