Die-in in front of Tate Modern, London, 2019. (Photo by Claire Doherty/In Pictures)Alicia Kennedy, one of the most celebrated food writers of her generation, sometimes seems to approach food as a series of moral dilemmas waiting to be untangled. In her new memoir, On Eating—a useful starting point to consider progressive culture as a whole—she writes that alcohol “is one of the most wasteful things one can consume, producing twelve times the was…