Summary: In this small 12-week randomized controlled trial of 36 male recreational athletes (aged 30 to 45 years) with type 2 diabetes, only the combined diet plus physical activity arm improved both glycemic and body-composition markers, with statistically significant but small effect sizes (HbA1c p<0.05, ES=0.23; HOMA-IR ES=0.39). Physical activity alone reduced only HbA1c, and nutrition alone mainly improved lipids.
PICO Summary
| Element | Detail |
|---|---|
| Population | 36 male recreational athletes aged 30 to 45 years with type 2 diabetes mellitus, analysed in a four-arm randomized controlled trial conducted in Tunisia (roughly 9 participants per arm). |
| Intervention | A 12-week structured programme combining a therapeutic nutritional regimen with supervised physical activity (combined PA+NR arm). Two single-component arms were also studied: physical activity alone (PA) and nutritional regimen alone (NR). |
| Comparison | A control group receiving no structured diet or physical-activity programme, plus the two single-component arms serving as internal comparators. |
| Outcome | The combined PA+NR arm improved significantly versus baseline across body mass (p<0.05, 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), HOMA-IR (ES=0.39) and HDL-C (ES=0.29). The PA arm improved HbA1c only; the NR arm chiefly improved lipids; the control arm showed no significant change. Effect sizes were small, absolute HbA1c values and between-group confidence intervals were not reported in the abstract, and no formal NNT is available. |
Diet plus exercise in male athletes with T2DM
RCT · type 2 diabetes · 12 weeks
Only the combined diet plus exercise arm improved both glycemic and body-composition markers, but effect sizes were small and absolute changes were not reported in this underpowered 36-man trial.
Expert Commentary
This randomized controlled trial supports a long-standing principle, that pairing structured nutrition with exercise outperforms either alone, and the direction of effect is consistent and biologically plausible across glycemic, insulin-sensitivity and lipid markers. The verdict, however, must stay measured. With only 36 men analysed across four arms, roughly nine per group, the trial is markedly underpowered, and the reported effect sizes are small (mostly ES below 0.4). The dominant limitation is this sample size combined with the absence of reported between-group confidence intervals and absolute HbA1c changes, which means the magnitude of clinical benefit cannot be judged from the available data and within-group significance may overstate real-world impact. The population is also narrow, young to middle-aged active men, so generalisation to older, sedentary or female patients is not warranted. Can I use this with my patients? Cautiously, and only as reinforcement for an active male patient with type 2 diabetes who is already motivated to combine a structured diet with exercise, not as evidence of a defined HbA1c target reduction. The design appears unblinded, which is unavoidable for lifestyle interventions but inflates expectation effects. No industry or manufacturer sponsorship was apparent. Larger, adequately powered trials reporting absolute outcomes and durability are needed before firmer recommendations.
References
Chouk K, Triki R, Dergaa I, Ceylan HÍ, 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