Optimising patient weight management prior to joint replacement to improve outcomes: a feasibility study with embedded qualitative component

Dietitian-led program (intervention group): Participants will be assessed by the physiotherapist (PT) and the clinical nurse consultant (CNC) and managed according to the same principles as the usual care (comparator) group including consultation with the patient’s GP as required. Thus, the intervention - commencing at the point of entry to the waitlist program - will include advice regarding physical activity (to maintain muscle), pain management and chronic disease management, but will provide the anti-inflammatory weight loss diet in place of the usual diet information. The diet will be administered by an onsite dietitian (in the hospital clinic) who will use both 1-to-1 (in person and via telephone as required, delivered initially weekly (weeks 1 and 2) then fortnightly (weeks 4 and 6), followed by 4-weekly contact for the remainder of the program (nine months after recruitment) and group consultations to deliver the program (4 x group sessions with a focus on key elements of the LIFT-diet: extra virgin olive oil, foods high in lutein, anthocyanins, and anti-oxidants (including vitamin C rich foods), fish and legumes). The program will be personalised in order to accommodate cultural and special dietary requirements. The program will recommend energy intake be reduced by up to 500 calories/day and will follow the principals of a low-inflammatory diet such as those recommended by the Harvard Medical School https://www.health.harvard.edu/staying-healthy/foods-that-fight-inflammation. The diet material will build on material developed by CI Flood for a concurrent study (among people with non-alcoholic fatty liver disease). The LIFT-diet, will emphasise foods rich in antioxidants, polyphenols (including anthocyanins, flavanols), carotenoids (particularly lutein and lycopene), long-chain omega-3 fatty acids, low-glycemic index foods and will provide advice to reduce pro-inflammatory foods, such as refined carbohydrate foods, highly processed take-away food items, sugary drinks, processed meat, alcoholic beverages and saturated and trans fat food sources. The LIFT-diet will include advice to consume tomatoes (good source of lycopene, oxylipin and coumarin), dark green leafy vegetables (good lutein source), fruit (e.g. strawberries, blueberries, oranges and cherries) (good anthocyanin source), legumes, spices and herbs (daily), and nuts (e.g. walnuts, almonds and pistachio) (4-5x/week), and fatty fish (2x/week), and extra virgin olive oil (main fat source, used daily; good source of polyphenolic compounds). This diet is not only anti-inflammatory but lower in energy intake, with the emphasis on reducing highly processed food items. Due to the vast ethnocultural diversity of South-West Sydney, we will work with consumer partners to aid the applicability of the education material to such populations, incorporating material suitable for traditional diets including information about food preparation and recipes. ‘Consumer partners’ will comprise members of the SPHERE MSK CCC and people the latter invite to contribute from their respective community connections. As for the usual care group, the participant will be referred back to their GP if a change in their health or weight necessitates a review. Adherence to the diet will be assessed using dietary surveys. Participants will be encourage to adhere at each visit with the dietitian. For the qualitative component, a purposive sample of people (based on their level of weight loss - change within 5% of baseline weight; loss 5% or more of baseline; gain 5% or more of baseline) from this group will be interviewed about the barriers and enablers to weight loss.