The Snacking @ Otago Study: The effects of consuming almonds or biscuits on body weight and satiety

The study will examine the acute and long-term effects of consuming almonds and biscuits on body weight management and satiety among people who regularly snack on discretionary foods. This study has two components - an acute phase and a long-term study. The long-term phase assess the effects is a one-year randomised parallel study with 2 arms: Arm 1: Almonds (participants will receive 42.5 grams per day (g/d) or 10% of energy (whichever is more) of raw and dry roasted almonds. They will be asked to eat the study foods as snacks throughout the day. Arm 2: Biscuits (will provide the same energy as the almond) Compliance during the long-term study will be measured by food diaries, return and weighing of snack bags and uneaten snacks, and plasma vitamin E concentrations will also be assessed as a measure of compliance to consuming the almonds. The acute phase will assess the effects of consuming raw almonds (42.5 g/d or 10% of energy (whichever is more)) or biscuits ( same energy as almonds) on blood glucose response and satiety. This will be a crossover design where participants will receive the treatments in random order. Participants will attend two clinic visits of around 5 hours, with a one week washout between treatments. Participants will attend the clinic after fasting for at least 8-10 hours. They will be provided with a standardised breakfast comprising of 20% of their total energy requirements. The breakfast will consist of ready-to-eat muesli (Toasted Muesli Golden Oats and Fruit; Sanitarium, Auckland, Christchurch, New Zealand), fruit-flavoured non-fat yoghurt (Fresh’n Fruity Wildly Berry yoghurt; Fonterra Brands Ltd, Auckland, New Zealand) and 3.3%-fat milk (Meadow Fresh Standard Milk; Goodman Fielder, Auckland, New Zealand), and provide, on average, 53% energy from carbohydrate, 14% energy from protein and 30% energy from fat. Two hours after the breakfast they will be provided with the almond or biscuit snack. They will be asked to consume this within 10 minutes. Before they consume the snack, and at intervals of 15, 30, 45, 60, 90 and 120 minutes following snack consumption, we will take a fingerpick blood sample for measurement of blood glucose. Participants will also record hunger and satiety ratings at these time points using 100 mm visual analogue scales. Two hours following snack consumption, participants will consume an ad libitum lunch. They will be offered sandwiches and will be asked to eat until they are comfortably full over 20 minutes. Participants will complete a weighed food diary for the remainder of the day. The acute phase and long term study will be separated by at least two weeks. There will be a 2-week no-nut run-in prior to the start of the long-term intervention.