Table 1.

Eligibility criteria

Inclusion criteria	Exclusion criteria
Fulfil National Institute for Health and Care Excellence31 clinical criteria for osteoarthritis: Activity-related joint pain with average knee pain severity ≥4 on 11-point Numeric Rating Scale (NRS, where 0=no pain, 10=worst pain possible) in the past week. No morning stiffness or morning stiffness ≤30 min. Age ≥45 years.	Another reason than OA for knee symptoms (eg, tumour, fibromyalgia)
Age ≤85 years—due to potential safety reasons and additional comorbidities that may hinder capacity for dietary adherence	Planning to have knee surgery in next 6 months
History of knee pain on most days of the past month	Already strictly following an anti-inflammatory diet (eg, low carbohydrate, paleo, Mediterranean)
History of knee pain for at least 3 months	Following a habitual diet that excludes animal products (eg, vegan)
Be willing and able to attend 3–4 phone consults and 12-week and 6-month follow-up assessments	Unable to follow anti-inflammatory diet (eg, medically contraindicated, history of food allergy/hypersensitivity, family reasons)
Able to understand written and spoken English and to give informed consent	Taking the following diabetic medication that affects blood sugar levels (ie, insulin, SGLT 2 inhibitors, sulfonylureas) to mitigate the risk of hypoglycaemia/ketoacidosis
	Contraindications for DXA scans (eg, pregnant, breast feeding, planning pregnancy in next 6 months, >200 kg body weight)
	>5 kg weight fluctuation in past 3 months (ie, unstable weight)
	Unable to understand written and spoken English
	Knee injection, injury or surgery in the past 3 months
	A diagnosed psychiatric disorder (excluding anxiety and depression)
	History of eating disorder or bariatric surgery
	Had all eligible knee joints replaced by arthroplasty

DXA, dual-energy X-ray absorptiometry; OA, osteoarthritis; SGLT, sodium glucose co-transporter.