Assessing the impact of a sweetened beverage tax in Australia

INTERVENTION: Participants allocated to the one of three beverage tax conditions. During a telephone survey, participants will be read a list of beverages typically available from an Australian supermarket. The survey will be conducted once only. For each beverage product type, participants will be provided with information about the price and container sizes (up to three) which the product can be purchased (for example, a 2 litre bottle, a 1.5 litre bottle and a 600ml bottle) based on data regarding the most frequently purchased container size for that beverage product. For each beverage type, participants will be asked to report the number of products (in each container size), they would intend to purchase for the consumption of their household during a typical grocery shop. The price of beverages containing caloric sweetener will be experimentally manipulated. For group 1: the price of such products will be increased by 10% For group 2: the price of such products will be increased by 20% For group 3: the price of such products will be increased by 30% CONDITION: Nutrition Obesity diet PRIMARY OUTCOME: Mean Kilojoules per household of beverages intended to be purchased for household consumption (by group) SECONDARY OUTCOME: Nil INCLUSION CRITERIA: Participants will be sampled from a cohort of adults previously recruited into a random household general health telephone survey and who agreed to be approach for future opportunities for research participation. Additionally, to be eligible, participants must be 16 years or older be able to converse in English and have some current responsibility for household grocery shopping.