Think knee pain is just ageing? Doctors say your weight may be the real culprit
Excess body weight places extreme stress on the knees, accelerating cartilage damage and arthritis. A knee surgeon explains how weight gain triggers pain, inflammation and long-term joint problems, and why early action matters.
Knee pain is often blamed on age, old injuries or “bad posture”. But orthopaedic surgeons say one of the most underestimated causes is excess body weight. This can cause a problem even in people who are otherwise healthy and active.
According to Dr Amyn Rajani, Consultant Knee and Shoulder Surgeon, Mumbai, the knee joint is not designed to carry prolonged overload, and weight gain accelerates damage much earlier than most people realise.
Your knees carry far more than your body weight
Many people assume their knees only support their actual weight. In reality, everyday movements multiply the load dramatically. “Even routine activities like climbing stairs, sitting down or standing up involve the knee bearing three to six times your body weight,” says Dr Rajani. “When extra kilos are added, the joint stays constantly overloaded, which speeds up cartilage wear and tear.”
Over time, this repeated stress causes the protective cartilage to thin and break down, setting the stage for chronic pain.
Why does arthritis show up earlier in overweight individuals?
Osteoarthritis isn’t just an “old age” problem. Excess weight pushes the condition to appear sooner and progress faster. “Overweight individuals tend to develop osteoarthritis much earlier, and once it starts, the damage progresses more rapidly,” Dr Rajani explains. “As cartilage breaks down, the knee becomes stiff, painful and less mobile.”This explains why knee pain often begins subtly, with discomfort after walks, stiffness in the morning, before becoming persistent.
Fat tissue fuels inflammation, not just weight gain
One common myth is that body fat is harmless padding. Medically, it’s far from passive. “Fat tissue releases chemicals that increase inflammation in the body,” says Dr Rajani. “These chemicals weaken cartilage, promote swelling in the joints and worsen pain and stiffness.” This inflammatory effect means that even modest weight gain can worsen joint health, especially if knee pain has already started.
How weight affects leg alignment and joint balance
Excess body weight doesn’t just strain the knee; it can also change how the legs align. “Being overweight can shift the leg axis into bow-leg or knock-knee patterns,” Dr Rajani notes. “This creates uneven pressure on different parts of the knee, accelerating damage on one side of the joint.” Once alignment changes, pain often becomes more localised and harder to reverse without intervention.
Weaker muscles, higher injury risk
As the knees struggle to cope, surrounding muscles begin to fatigue.
“Extra weight keeps the knee muscles under constant stress, making them weaker over time,” explains Dr Rajani. “This reduces stability and increases the risk of further joint damage.”
The meniscus, the knee’s natural shock absorber, is also vulnerable. “Excess load increases the risk of meniscus tears, which can cause sharp pain and even knee locking,” he adds.
Knee pain is rarely sudden; it’s cumulative. And excess body weight quietly compounds the damage with every step. The good news? Even small, sustained weight loss reduces joint stress significantly, slows cartilage breakdown and eases pain over time. Your knees remember everything. Treat them kindly, they’re doing far more heavy lifting than you think.
Disclaimer: Tips and suggestions mentioned in the article are for general information purposes only and should not be construed as professional medical advice. Always consult your doctor or a dietician before starting any fitness programme or making any changes to your diet.