Individualised Diet and Exercise for Asthma and Lung Function (IDEAL) study

The intervention group will attend once monthly visits over 16 weeks (i.e., weeks 0, 4, 8, 12, and 16) with a dietitian as well as a physiotherapist/exercise physiologist. Each session will consist of one-on-one consultation with both the dietitian and physiotherapist/exercise physiologist. Sessions will be delivered face-to-face with an estimated total duration of 90 minutes. The dietitian intervention involves Medical Nutrition Therapy, according to the Nutrition Care Process Model, with the goal of modifying the intake of foods and nutrients known to be associated with asthma outcomes, metabolic health, and the gut microbiome (e.g., fruits and vegetables, whole grain foods, fish, legumes, low-fat dairy, soluble fibre, phytochemicals, monounsaturated fatty acids and omega-3 fatty acids). The dietitian will guide participants to follow a reduced energy diet (2000-4000kJ/day energy deficit), which will lead to a modest weight loss (approximately 5-10% body weight over 16 weeks). The first session will commence with a nutrition assessment and determination of a nutrition diagnosis(es). A nutrition diagnosis is the identification of an existing nutrition problem(s) that the dietitian will be responsible for treating (e.g., high saturated fat intake), which differs from a medical diagnosis (e.g., diabetes). The nutrition diagnosis(es) will inform individualised nutrition intervention goals, in collaboration with the participant. Person-centred nutrition counselling will then commence, which will target the nutrition intervention goals and will focus on the participants needs (preferences, eating styles, comorbidities, etc.). Counselling will focus on nutrition education, behaviour modification, and motivational strategies. At each subsequent medical nutrition therapy session, the dietitian will conduct a nutrition re assessment and review the nutrition diagnosis(es), ensuring each counselling session is individualised. To promote mindful eating, participants will keep a food diary using the Easy Diet Diary app, to be sent to the dietitian fortnightly for adherence monitoring. The dietitian will periodically email participants to offer feedback and motivation. The Physiotherapist or Exercise Physiologist will prescribe an individualised physical activity programme, with the goal of meeting the Australian physical activity guidelines (150 minutes of moderate-vigorous aerobic physical activity and two muscle strengthening activity sessions per week). Aerobic exercise is also referred to as cardiovascular exercise and the aim of this type of exercise can be to improve fitness and endurance. Examples of aerobic exercise can include activities like walking, swimming, or cycling. Resistance exercise is also known as strengthening exercise. This type of exercise is aiming to increase muscle strength. Examples of resistance exercise can include lifting hand held weights, using resistance bands or tubing, or doing movements using body weight as the resistance like wall push ups. The physical activity intervention will commence with a physical activity screening assessment which will determine risk and safety to exercise, assessed via the adult pre-exercise screening system (APSS), and exercise preferences, barriers, and goals, assessed via the personalized exercise questionnaire (PEQ). Each participant will receive a physical activity starter pack (physical activity tracker, selection of resistance bands and/or free weights). They will also receive education and resources throughout the program to suit their individual needs. The physical activity monitor will assist in guiding their exercise intensity, by allowing the participant to monitor their heart rate during exercise and work towards a target range. The activity monitor will also provide an element of motivation and assist the physiotherapist in monitoring adherence. The physiotherapist/exercise physiologist will periodically email participants to offer feedback and motivation.