Knee Osteoarthritis and Body Weight — 1 kg Makes a 4 kg Difference
Table of Contents
The relationship between body weight and knee load
The force on the knee during walking is approximately 3–4 times body weight. It rises to 4–6 times when going up and down stairs, and to 7–8 times when squatting. Therefore, losing 1 kg of body weight reduces the repetitive load on the knee by about 4 kg during walking. Considering the cumulative effect of taking thousands of steps each day, this is an enormous difference.
BMI and the link with osteoarthritis
Studies show that people with a BMI of 25 or higher are about 4.5 times more likely to develop knee osteoarthritis than those of normal weight. With obesity (BMI 30 or higher), the disease also progresses more than twice as fast. In addition, inflammatory substances called adipokines secreted by fat tissue travel through the bloodstream to the joint, adding systemic inflammation on top of the mechanical damage from weight alone.
Clinical evidence — the effects of weight loss
The IDEA study (2013) showed that when overweight osteoarthritis patients lost 10% or more of their body weight, knee pain decreased by more than 50% and walking function improved significantly. Even a 5% reduction in body weight lowers inflammatory markers (CRP, IL-6) and slows the rate of cartilage loss.
Combined Korean medicine weight-loss strategy
- Herbal medicine — modified Bangpungtongseongsan: A representative formula that supports appetite control and metabolic activation. It is particularly effective in damp-phlegm (濕痰) constitutions and is taken at separate times from the knee herbal medicine.
- Auricular acupuncture: Needles or ear seeds applied to appetite-suppressing ear points (Hunger, Shenmen, Stomach) reduce overeating impulses.
- Dietary guidance: Lowering carbohydrates to 40–45% of intake and increasing protein helps reduce body fat without losing muscle mass.
Caution — excessive exercise can backfire
Trying to lose weight with high-impact exercise such as running or hiking when osteoarthritis is already present accelerates cartilage damage. Aerobic exercise with low joint loading — such as aquatic walking, indoor cycling, and swimming — is more appropriate. Managing pain with herbal medicine and acupuncture while gradually increasing activity is the safe path to weight loss.