Objectives: This study aimed to evaluate the effects of ≥ 3% body weight loss at 6 months in male workers and verify the application possibility of assessment at 3 months after specific health guidance.
Methods: We recruited 5,031 Japanese male workers (aged 40-64 years) who had undergone health checkups and completed specific health guidance from 2008 to 2017. Participants were divided into three groups according to the percentage of weight reduction (≥ 3%, 0%-3%, ≤ 0%) after 6 months of health guidance. We compared the body weight, waist circumference, and blood pressure at 3- and 6-months with baseline data within and between groups. Similarly, in the medical examination of the next fiscal year (n = 2,889), body weight, waist circumference, blood pressure, triglyceride levels, high-density lipoprotein-cholesterol (HDL-C) levels, plasma glucose levels, and the prevalence and improvement rates of metabolic syndrome (MetS) of specific health checkups were also compared. Furthermore, we calculated the weight reduction target after 3 months to arrive at a ≥ 3% weight reduction for 6 months. Based on the target, we investigated the prevalence and improvement rates of MetS in the next fiscal year.
Results: A total of 1,349 (26.8%) participants had a ≥ 3% weight reduction, 2,059 (40.9%) had a < 3% weight reduction, and 1,623 (32.3%) had no weight reduction. At the 6-month follow-up, waist circumference and blood pressure levels had increasingly improved with greater reductions in weight. The following year, body weight, waist circumference, blood pressure, triglyceride levels, HDL-C levels, and plasma glucose levels had improved in the ≥ 3% weight loss group, whereas plasma glucose levels had not improved in the 0-3% weight loss group. Additionally, only triglyceride levels and diastolic blood pressure had improved in the no weight reduction group. In the ≥ 3% weight loss group, the prevalence rate of MetS was the lowest (7.6%), and the improvement rate of MetS was the highest (70.7%). Furthermore, the weight reduction target after 3 months to arrive at a ≥ 3% body weight reduction at 6 months was 2.0% weight reduction. Those who reduced weight ≥ 2.0% had better prevalence and improvement rates of MetS than those who reduced weight < 2.0%.
Conclusions: Our findings indicated that the objective of losing ≥ 3% of body weight at 6 months in male workers after completing specific health guidance was effective and that assessment after 3 months based on setting a 2.0% weight reduction target was applicable.