Weight loss exclusively through diet for knee osteoarthritis

Knee osteoarthritis is a highly prevalent chronic disease, associated with various risk factors and with multiple treatment options. Overweight is among the main risk factors and also constitutes an aggravating factor of the symptoms. It has been suggested that weight loss would be able to improve symptoms and to stop the progression. It can be achieved by several methods: exercise, diet, drugs, surgery, or a combination of them. Apparently, diet is a reasonable option given its availability, low technical complexity and greater acceptability, especially in the population susceptible to developing knee osteoarthritis, but it is not clear whether the benefit of diet as the only intervention leads to symptomatic improvement.

We searched in Epistemonikos, the largest database of systematic reviews in health, which is maintained by screening multiple information sources, including MEDLINE, EMBASE, Cochrane, among others. We extracted data from the systematic reviews, reanalyzed data of primary studies, conducted a meta-analysis and generated a summary of findings table using the GRADE approach.

We identified seven systematic reviews including six primary studies overall, all corresponding to randomized trials. We concluded diet may improve functionality and quality of life, with probably minimal or no adverse effects. However, we are uncertain whether diet reduces pain as the certainty of the evidence has been assessed as very low.