Table 3.

Summary of dietary interventions that may be of benefit in OA

Intervention	Detail of recommended interventions	Points to note
Weight reduction in overweight or obese patients	An initial aim of 10% body weight reduction should be included in a first-line approach for obese patients with OA. Overall aim for obese/overweight patients is for BMI within the healthy range (18.5–25 kg/m2) Dietary modification should include moderate energy restriction without compromising micronutrient intake Exercise should be encouraged including aspects of aerobic exercise, strengthening and flexibility that should be tailored to mobility	Regular clinical contact and monitoring, including dietetic input, are essential for dietary modification. Clinical input should incorporate a focus on behaviour change
Beneficial dietary-lipid modification in OA patients	Reduce intake of n-6 fatty acids by substituting oils rich in mono-unsaturates such as rapeseed, canola and olive oils. Aim to increase intake of long-chain n-3 fatty acids via a direct source of EPA/DHA; increase intake of oily fish; aim to consume a minimum one portion per week (as in general healthy eating guidelines) and preferably two Consider a daily standard fish oil supplement (1–2 capsules/day)	Women who are pregnant or breastfeeding should avoid fish with high levels of mercury (i.e. shark, swordfish and king mackerel) [46] and should avoid cod-liver oil due to the vitamin A content [47]
Dietary management of cholesterol, serum lipids and comorbidities, CVD and MetS	A cholesterol-lowering dietary portfolio should be advocated to patients with raised serum cholesterol (>5 mmol/l/>200 mg/dl) or LDL-C (>3 mmol/l/>100 mg/dl)a to reduce CHD risk with the potential for OA benefit ≥2 g/day plant stanols/sterols [49] Reduce SFA intake to < 11% total energy (around 31 g/day for males and 24 g/day for females) Ensure daily intake of viscous fibre (e.g. oats), soy protein (25 g) and nuts (30 g) For obese/overweight patients, weight reductionb remains of primary importance both for OA symptom management and reduction in risk of the co-morbidities, CVD and MetS	Sources of soy protein include soy milk (7.5 g soy protein per 250 ml serving), soy/edamame beans and tofu
To achieve adequate levels of vitamins A, C and E	Ensure adequate daily intake through consumption of rich dietary sources (see supplementary Table S2, available at Rheumatology online) Adult recommended intakes are shown below: Vitamin A (retinol equivalent): 650–750 µg/day (Europe [50]); 700–900 µg/day (USA [51])c Vitamin C: 95–110 mg/day (Europe [52]); 75–90 mg (USA [51])c Vitamin E (α-tocopherol equivalent): an adequate intake level of 11–13 mg/day (Europe [53]); 15 mg/day (USA [51, 107]) Only consider a multivitamin supplement if dietary intake of these nutrients is insufficient to meet dietary recommendations. Obtaining intake through diet is preferable	US guidelines suggest an additional 30 mg/day Vitamin C for smokers
To increase vitamin D intake/status	Increase consumption of vitamin-D-rich foods, for example, oily fish, eggs (yolks), vitamin-D-fortified spreads, fortified milk, fortified cereals (see supplementary Table S2, available at Rheumatology online) During the summer months, daily sunlight exposure (without protective cream/lotion) of approximately 10–20 min (depending on skin type, time of day, altitude and latitude) should be sufficient to produce adequate vitamin D [54, 55] With minimal sun exposure, supplementation of 15–20 µg/day should be encouraged, based on European and American guidelines, to ensure sufficient vitamin D concentration [54, 55] Maintaining a healthy BMI, that is, between 18.5 and 25 kg/m2, will reduce the risk of vitamin D sequestration in adipose tissue [54, 55, 126, 127]
To increase vitamin K intake	Increase green-vegetable consumption, particularly of rich sources such as spinach, Brussels sprouts, kale and broccoli [56] (see supplementary Table S2, available at Rheumatology online for list of sources) Certain fats and oils (e.g. blended vegetable oil, olive oil and margarine [56]) contain small amounts of vitamin K and therefore utilizing these in cooking or as plant spreads may increase intake	The addition of a fat (such as olive oil) to a vitamin K source may increase bioavailability, as vitamin K is fat-soluble

^aNHS reference ranges/NHLBI [48] reference ranges, ^bSee recommendations for weight-reduction in overweight/obese OA patients, and ^cExcluding pregnant/lactating women. CVD: cardiovascular disease; DHA: docosahexaenoic acid; EPA: eicosapentaenoic acid; MetS: metabolic syndrome.