Taken from Arthritis  Foundation

A key study published in Arthritis & Rheumatism of overweight and obese adults with knee osteoarthritis (OA) found that losing one pound of weight resulted in four pounds of pressure being removed from the knees. In other words, losing just 10 pounds would relieve 40 pounds of pressure from your knees. 

Here are some ways:

1.  Reduce pressure on your joints. Ease pain. 

Multiple studies show that losing weight results in arthritis pain relief. A 2018 study published in Arthritis Care and Research went further to find that losing more weight – to an extent -- results in more pain relief.  The study of overweight and obese older adults with pain from knee OA found that greater weight loss resulted in better outcomes than losing a smaller amount of weight. Losing 10–20 percent of starting body weight improved pain, function, and quality of life better than losing just five percent of body weight. 

2.  Reduce inflammation. 

Fat itself is an active tissue that creates and releases pro-inflammatory chemicals. By reducing fat stores in the body, your body’s overall inflammation will go down. A 2018 article published in Autoimmunity Reviews explained that obesity can activate and sustain body-wide low-grade inflammation. This inflammation can amplify and aggravate autoimmune disorders, such as rheumatoid arthritis, psoriatic arthritis, lupus and their associated comorbidities (like heart disease).  

3.  Reduce Disease Activity. 

Losing weight can reduce the overall severity of your arthritis.  A 2018 study published in International Journal of Clinical Rheumatology reviewed the records of 171 RA patients and found that overweight or obese people who lost at least 5 kg (10.2 pounds) were three times as likely to have improved disease activity compared to those who did not lose weight. A smaller 2019 study published in Arthritis Research & Therapy found that short-term weight loss in obese people with psoriatic arthritis (PsA) yielded “significant positive effects” on disease activity in joints, entheses, and skin.