When you replace all meat in your diet with Kangaroo meat (australus) alongside a vegetarian type diet.

Eating a vegetarian diet with the addition of australus meat as a choice with environmental benefits because indigenous wild kangaroos require no extra land or water for farming and produce little methane (a greenhouse gas), unlike cattle. Advocates of Kangatarianism also choose it because Australian kangaroos live natural lives and eat organic food. For similar reasons, Australians have discussed eating only the meat of Australian feral camels ("Cameltarianism")