Obesity in older adults: effect of exercise and weight loss on physiology and function.

ARM 1:Very Low Energy Diet (VLED) - Optifast plus exercise Optifast is a commercially available Very Low Energy diet. The diet prescribed to the participants will consist of 1 sachet/bar/soup prepared as per directions on box, for each of breakfast and lunch. Dinner will consist of a serve of lean protein (lean red meat/fish/tofu) plus a serve of non-starchy vegetables plus a teaspoon of oil to contract the gallbladder. The target energy intake is 800kCal per day and the duration of the intervention is 12 weeks. Exercise: 3x45 minute sessions per week, for 12 weeks. The program is called "Heartmoves" and was designed by the National Heart Foundation especially for older people. It involves resistance, balance, strength and endurance components. The intensity of the exercise will be guided by the participant as the moves can be modified. The classes will either be delivered by a trained Heartmoves aerobics instructor or the patient can do the exercise at home by watching a DVD. A physiotherapist will be involved in the study to treat/monitor any injuries. Arm 2: Hypocaloric Diet Plus exercise Hypocaloric diet: A diet will be prescribed by a dietician tailored to the participant. The diet will contain enough nutrients for the participant but have fewer calories than what they need (approximately 2000kJ/day deficit from basal requirements), which will result in slow weight loss. The duration of the intervention will be 12 weeks. The participant will have a long (1 hour) consultation at the beginning of the trial and shorter (approx 30 minute) consultations every 2 weeks during the trial). The exercise component will be Heartmoves as above.