The cheapest and most reliable technique for changing a food system is to make certain foods taboo.
Religion is the lowest-cost cultural tool.
No ads or medical research. Free education by parents. Vegans and vegetarians understand this simplicity. Eat Not This Flesh lovingly details the origin and spread of food taboos, challenging certain claims that it's all hygienic or ecological. Simoons elaborates the tangle of human moral history which can feed or starve taboos against beef, pork, chicken, eggs, horse, camel, dog, and fish.