Effects of main and side dishes at different meal timings on metabolic parameters in older adults: A 12-week randomized controlled trial

We aimed to examine the effects of main and side dishes at given at different time on metabolic parameters in older adults. This randomized controlled trial included, conducted June through October 2023, 43 older adults, aged 65 years and older, who were randomly divided into four groups: control (<i>n</i> = 8), morning (<i>n</i> = 12, 0700 h to 0900 h), lunch (<i>n</i> = 11, 1100 to 1300 h), and dinner (<i>n</i> = 12, 1700 to 1900 h). The participants in the control group maintained their usual dietary habits for 12 weeks. The morning, lunch, and dinner groups were each asked to consume the test meal, consisting of one main and four side dishes, once a day at a specific time for 12 consecutive weeks. Blood parameters and body composition were evaluated in the fasting state before and after the intervention. The HbA1c levels after the intervention in the morning and dinner groups were significantly lower than those at baseline (morning, <i>p</i> = 0.031; dinner, <i>p</i> = 0.016). Additionally, the body weight (BW) and BMIs after the intervention in the dinner group were significantly lower than those at baseline (BW, <i>p</i> = 0.002; BMI, <i>p</i> = 0.001). These findings indicate that the timing of main and side dishes intake may influence changes in glucose tolerance and BMI without decreasing nutritional intake.