Many people with overweight or obesity experience knee pain. In many cases, losing weight can help reduce pain and lower the risk of osteoarthritis (OA).

According to one study, 3.7 percent of people with a healthy weight (BMI 18.5– have OA of the knee, but it affects 19.5 percent of those with grade 2 obesity, or a BMI of 35–39.9.

Having additional weight puts extra pressure on your knees. This can result in chronic pain and other complications, including OA. Inflammation may also play a role.

How weight affects knee pain

Maintaining a healthy weight has many health benefits, including:

• reducing pressure on the knees
• reducing joint inflammation
• reducing the risk of various diseases

Decreasing weight-bearing pressure on the knees

For people with overweight, each pound they lose can reduce the load on their knee joint by 4 pounds (1.81 kg).

That means if you lose 10 pounds (4.54 kg), there’ll be 40 pounds (18.14 kg) less weight in each step for your knees to support.

Less pressure means less wear and tear on the knees and a lower risk of osteoarthritis (OA).

Current guidelines recommend weight loss as a strategy for managing OA of the knee.

According to the American College of Rheumatology/Arthritis Foundation, losing 5 percent or more of your body weight can have a positive effect on both knee function and treatment outcomes.

Reducing inflammation in the body

OA has long been considered a wear-and-tear disease. Prolonged, excess pressure on the joints will cause inflammation.

But recent research suggests that inflammation may be a risk factor rather than a consequence.

Obesity may increase inflammation levels in the body, which may lead to joint pain. Losing weight can reduce this inflammatory response.

One review looked at data for people who lost an average of around 2 pounds (0.91 kg) a month over a range of 3 months to 2 years. In most studies, markers of inflammation in their bodies fell significantly.

Link with metabolic syndrome

Scientists have found links between:

• obesity
• type 2 diabetes
• cardiovascular disease
• other health issues

These all form part of a collection of conditions known jointly as metabolic syndrome. They all appear to involve high levels of inflammation, and they may all influence each other.

There’s growing evidence that OA may also be part of metabolic syndrome.

Following a diet that reduces the risk, which helps slow the progression of metabolic syndrome, may also help with OA.

This includes eating fresh foods that are high in nutrients, with a focus on:

• fresh fruits and vegetables, which provide antioxidants and other nutrients
• fiber-rich foods, such as whole foods and plant-based foods
• healthy oils, such as olive oil

Foods to avoid include those that:

• have added sugar, fat, and salt
• are highly processed
• contain saturated and trans fats, as these may raise cholesterol levels

Exercise

Together with dietary choices, exercise can help you lose weight and reduce the risk of OA.

Current guidelines recommend the following activities:

• walking
• cycling
• strengthening exercises
• water-based activities
• tai chi
• yoga

As well as contributing to weight loss, these can improve strength and flexibility, and they may also reduce stress. Stress can contribute to inflammation, which may worsen knee pain.

To help you keep yourself motivated and moving, we'll send you treatment updates and pain management tips.

Tips for losing weight

Here are some other steps you can take to start losing weight.

• Reduce portion sizes.
• Add one vegetable to your plate.
• Go for a walk after a meal.
• Take the stairs rather than the escalator or elevator.
• Pack your own lunch instead of eating out.
• Use a pedometer and challenge yourself to walk further.

Takeaway

There’s a link between overweight, obesity, and OA. A high body weight or body mass index (BMI) can put additional pressure on your knees, increasing the chance of damage and pain.

If you have obesity and OA, a doctor may suggest setting a goal to lose 10 percent of your weight and aiming for a BMI of 18.5–25. This may help reduce knee pain and prevent joint damage from getting worse.

Losing weight can also help you manage other conditions that commonly occur as part of metabolic syndrome, such as:

• type 2 diabetes
• high blood pressure (hypertension)
• heart disease

Your healthcare provider can help you create a plan to lose weight.

Taking the necessary steps to manage your weight can help protect your knees from joint pain and reduce your risk of OA.