a decreasing trendP = 0.10
Subgroup analysis by age revealed a decreasing trend in body fat percentage among the younger group [MD = −2.61, 95%CI (−5.69, 0.47), P = 0.10], while the middle-aged group showed a significant decrease [MD = −5.30,95%CI (−10.09, −0.51), P = 0.03].