Increased consumption of foods with pulses (eg. lentils or chickpeas), which are a source of protein, is recommended due to their lower environmental impact than animal-sourced foods (Willett et al., 2019). However, data for the environmental and nutritional trade-offs for such a dietary shift has been lacking in the Australian context, and nutritional implications for specific population groups not considered. The diets of Australian adolescents are particularly poor, yet this age is critical for developing healthy lifestyle behaviour that can persist into adulthood. We aimed to assess the nutritional and environmental impact of increase pulse consumption, through a case study of a dietary shift of Australian adolescents from a ham sandwich to hummus sandwich. Nutritional analysis was undertaken using the Nutrient Rich Food index for adequate intake (NRF-ai) to evaluate nutritional value, weighted to reflect the proportion of the Australian adolescent population with inadequate/excessive intakes of 22 key nutrients (Ridoutt, 2021). Environmental impact of each sandwich was assessed using Life Cycle Assessment methodology across five impact categories – global warming potential, eutrophication, acidification, freshwater ecotoxicity and water scarcity. A sensitivity analysis was undertaken to test the influence of key variables for ham (imported from Europe or Australian) and hummus (commercial, or homemade with either canned or dried chickpeas). The NRF-ai score was also used as a functional unit to determine the nutritional ecoefficiency of each type of sandwich (environmental impact per NRF-ai). Nutritional affordability (NRF-ai per dollar cost to the consumer) was also calculated. Based on an equivalent nutritional value (one unit NRF-ai), a hummus sandwich has a lower impact on the environment than a ham sandwich, across all environmental impact categories. For example, considering adolescent boys’ diets, the global warming potential (GHGE) from a ham sandwich (using imported ham) is 10 times that of a hummus sandwich (using commercially made hummus). Per serve, a hummus sandwich has a much lower environmental impact, greater nutritional benefit, and is more affordable than a ham sandwich. The biggest contributors to environmental impact of the ham sandwich is feed and on-farm production (eg. emissions from manure). The growing of pulses has environmental benefits reducing acidification and eutrophication. Consumer choice can make a substantial difference to environmental and nutritional outcomes of the food system. If 50% of Australian adolescents consumed a hummus sandwich once a week for a year, instead of a ham sandwich, the reduction in GHGE would be equivalent to a person flying from Paris to Brisbane 3358 times (15,450,000 kg CO2eq). Strategies are needed to support consumer decisions to choose foods with environmental and nutritional benefits, such as pulses, through increasing access to healthy and appealing pulse based foods, and increasing consumer’s knowledge and skills to purchase, prepare and consume pulses.