Exercise & Training

The effects of short-term dietary calorie restriction combined with aerobic exercise on systemic inflammation in overweight or obese individuals with knee osteoarthritis: a randomised controlled trial.

TL;DR

Four weeks of moderate-intensity aerobic exercise training combined with calorie restriction led to a greater reduction in IL-6, but not CRP, compared to calorie restriction alone, and also led to greater reduction in knee pain in overweight or obese individuals with knee osteoarthritis.

Key Findings

IL-6 was significantly lower at post-intervention in the CR+E group compared to the CR group.

  • IL-6 was lower (p < 0.01; d = 1.69) at post-intervention in the CR+E group (1.36 mg/dL, 0.72 to 2.00) compared to CR group (2.98 mg/dL, 2.22–3.73)
  • Effect size was large (Cohen's d = 1.69)
  • Groups were compared by ANCOVA using pre-intervention value as a covariate
  • CR+E group performed five 30-min bouts of moderate intensity cycling per week in addition to a 5000 kcal/week dietary restriction

There was no significant difference in CRP between the CR+E and CR groups at post-intervention.

  • No difference in CRP between groups at post-intervention (p = 0.517, d = 0.31)
  • Effect size was small (Cohen's d = 0.31)
  • Both groups followed the same dietary calorie restriction of 5000 kcal/week for 4 weeks
  • Comparison was made using ANCOVA with pre-intervention value as a covariate

VAS knee pain was significantly lower at post-intervention in the CR+E group compared to the CR group.

  • VAS knee pain was lower (p < 0.01; d = 1.29) at post-intervention in the CR+E group (2, 1–3) compared to the CR group (4, 3–5)
  • Effect size was large (Cohen's d = 1.29)
  • 23 individuals with knee OA completed the trial (CR: n = 9; CR+E: n = 14)

Time to complete the stair climb test was significantly lower at post-intervention in the CR+E group compared to the CR group.

  • Stair climb test time was lower in the CR+E group compared to the CR group (p = 0.016, d = 1.17)
  • Effect size was large (Cohen's d = 1.17)
  • This indicates improved physical function in the CR+E group relative to CR alone after 4 weeks

The study enrolled overweight and obese individuals with knee osteoarthritis into a 4-week randomised controlled trial comparing calorie restriction alone to calorie restriction combined with aerobic exercise.

  • CR group: n = 9, BMI 30.0 ± 2.4 kg/m², age 56 ± 5 years
  • CR+E group: n = 14, BMI 32.3 ± 4.8 kg/m², age 57 ± 5 years
  • CR intervention involved reducing habitual energy intake by 5000 kcal/week for 4 weeks
  • CR+E intervention added five 30-min bouts of moderate intensity cycling per week to the same dietary restriction
  • Outcomes included blood markers of inflammation (CRP, IL-6), body composition, function, and pain; ClinicalTrials.gov ID: NCT05518890

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Citation

Deere R, Farrow M, Spellanzon B, Chowdhury E, Thompson D, Bilzon J. (2026). The effects of short-term dietary calorie restriction combined with aerobic exercise on systemic inflammation in overweight or obese individuals with knee osteoarthritis: a randomised controlled trial.. Musculoskeletal science &amp; practice. https://doi.org/10.1016/j.msksp.2026.103505