Summary: In 36 male recreational athletes (aged 30 to 45 years) with type 2 diabetes mellitus, a 12-week combined diet and physical activity programme was compared against diet alone, exercise alone, and a control arm. The combined arm produced statistically significant but small-magnitude improvements in body composition and glycaemic and lipid markers, including reduced HbA1c (p<0.05, effect size 0.23) and reduced HOMA-IR (p<0.05, effect size 0.39).
PICO Summary
| Element | Detail |
|---|---|
| Population | 36 male recreational athletes aged 30 to 45 years with type 2 diabetes mellitus; single-centre randomised controlled trial conducted in Tunisia. |
| Intervention | 12-week combined physical activity plus nutritional regimen (PA+NR), approximately 9 participants; assessed at baseline, midpoint, and end. |
| Comparison | Three parallel arms: physical activity alone (PA), nutritional regimen alone (NR), and a control group with no structured programme; each approximately 9 participants. |
| Outcome | In the combined arm, all reported within-group changes reached p<0.05 with small effect sizes: body mass (ES=0.29), body fat percentage (ES=0.31), muscle mass (ES=0.35), fasting blood sugar (ES=0.17), HbA1c (ES=0.23), LDL-C (ES=0.17), HDL-C (ES=0.29), and HOMA-IR (ES=0.39). The PA arm improved HbA1c only; the NR arm improved mainly lipids; the control group showed no significant change. No 95% confidence intervals, exact p-values, ARR, or NNT were reported. |
Expert Commentary
This small four-arm randomised trial is best read as hypothesis-generating rather than practice-changing. The combined diet-and-exercise arm outperformed the single-modality and control arms across body composition and metabolic markers, which is biologically coherent and consistent with the wider literature. The honest verdict, however, is one of cautious support: with only 36 participants split across four groups, roughly nine per arm, the study is markedly underpowered, and every reported effect size sits in the small range (0.17 to 0.39). The single most weighing limitation is this sample size, which inflates the risk that significant within-group findings are unstable and would not replicate; the absence of confidence intervals and exact p-values compounds the difficulty of judging precision. The population is also narrow, comprising relatively young, physically active men, so the results should not be extrapolated to older, sedentary, or female patients. Can I use this with my patients? Not yet as evidence of a specific protocol, although it reinforces the established and well-supported general advice that pairing structured nutrition with structured activity is preferable to either alone. A larger, adequately powered, multi-centre trial reporting confidence intervals and between-group comparisons is needed before any firm recommendation can be drawn from this particular dataset.
References
Chouk K, Triki R, Dergaa I, Ceylan Hİ, Bougrine H, Raul-Ioan M, Ben Abderrahman A. Effects of combined diet and physical activity on glycemic control and body composition in male recreational athletes with type 2 diabetes mellitus. Front Endocrinol (Lausanne). 2025;16:1525559. doi:10.3389/fendo.2025.1525559