A lady with blonde hair bending over grabbing at her knee. Wearing long black tights and a blue spray jacket. Mountains and paved road in the background

Osteoarthritis (OA) is the most common form of arthritis in Australia, and the fastest-growing cause of disability in the world, impacting people’s ability to perform their daily activities.

OA includes a number of potential problems relating to the joints, bones and cartilage:

  • Inflammation of tissue and damaged cartilage surrounding a joint
  • Abnormal bony growth around the edge of a joint
  • Wear and tear of ligaments and tendons

The role of inflammation and weight in osteoarthritis

Long-term low-grade whole-body inflammation has been shown to worsen general OA symptoms, as well as the symptoms that occur in those with a higher BMI due to extra weight on joints. The role of low-grade whole-body inflammation is shown through the association of higher BMI with the development of hand OA. It is now shown that overweight and obesity plays a double role in the development of OA, both from increased joint strain, and increased low-grade whole-body inflammation, which leads to joint degradation, creating a cycle of inflammation and damage.

Low-grade whole-body inflammation associated with higher BMI happens due to increased inflammatory cells coming from fat tissue. One particular inflammatory cell called leptin is produced by fat tissue near the knee and is associated with inflammation and cartilage damage both locally near the knee, and at other joints in the body.

Nutrition management strategies

High BMI is a modifiable factor in OA development and symptom severity. A reduction of just 5-10% of fat mass in those with high BMI can relieve symptoms, improve function, improve quality of life and reduce the role of fat tissue-related inflammation.

Strategies to target fat mass reduction include:

  • Portion education, with a focus on the healthy plate model (1/2 plate vegetables, ¼ plate carbohydrates, ¼ plate proteins)
  • Adequate intake of fibre, vegetables, fruits, nuts, seeds and legumes

It is also important to ensure regular and adequate protein intake to maintain muscle and cartilage health and function.

Protein-rich foods should be included with each meal, focusing on lean chicken, fish and seafood, tofu, lentils, legumes and beans, and low-fat dairy products including milk, yoghurt and cheese, with red meat consumed less often.

In addition to the above strategies, the Mediterranean diet has been well studied and shown to improve OA symptoms.

Mediterranean diets include foods high in polyphenols and omega-3 fatty acids, which help to reduce inflammation in the body.

Mediterranean diet principles include:

  • Plentiful consumption of vegetables, fruits, nuts and seeds, whole grains, low-fat dairy, beans and legumes, olive oil, seafood (salmon and tuna rich in omega-3), poultry, eggs, herbs and spices
  • Smaller amounts of red meat, only 2-3 times per week
  • Only occasional consumption of processed meats, refined grains (white bread, rice and pasta), and foods and beverages with added sugar (lollies, soft drinks, ice cream, sugary desserts)

Diet principles before surgery

For those that require joint replacement due to OA, appropriate nutrition before surgery is important to ensure positive outcomes after surgery and to minimise the risk of slow wound healing, infections or increased length of post-operative hospital stay. Particularly in older patients who are malnourished, there is a greater risk of muscle wasting after surgery if malnutrition is present before surgery.

Important nutritional considerations before surgery include lessening malnutrition risk and appropriate protein intake. It is important to note that malnutrition is also present in overweight or obese patients and that weight management can improve outcomes after surgery.

Adequate protein intake pre and post-surgery is important to maintain muscle mass and function and to ensure proper wound healing after surgery.


OA is one of the fastest-growing causes of disability worldwide. Local and whole-body inflammation contributes to joint wear and tear, leading to a cycle of ongoing inflammation and damage, which is worse in those with higher BMI.

Dietitians can provide individualised nutrition interventions for those with higher BMI to assist with fat mass reduction and can provide guidance on implementing Mediterranean diet principles to improve OA symptoms and reduce inflammation.

Even just 5-10% fat mass reduction can improve symptom severity, improve quality of life, and reduce low-grade whole-body inflammation.

And for those requiring joint replacement, appropriate nutrition before and after surgery minimises post-surgery risks including slow wound healing, infections and increased length of hospital stay post-surgery.


If you or someone you know may need help with managing their Diabetes get in contact with your local Sports & Spinal clinic today and book your next appointment with our Dietitian team!💙

Written By, Dietitian (APD) Caitlin Follett