I've been working on a paper with some French colleagues (Laurent Mueller and Bernard Ruffieux) using data from a food purchasing experiment in Grenoble and Lyon France looking at the effects of "fat taxes" and "thin subsidies" on poorer vs. richer households. The paper is still in review, so I won't yet go into the details of the results, but I can say that they closely align with the results of this new paper by Richard Tiffin and Matthew Salois that was just published in the European Review of Agricultural Economics.
They write that their:
“results reinforce the finding that a fiscal food policy based on a tax on saturated fats and a subsidy of fruits and vegetables is socially regressive”
and
“not only are the poorest households more negatively effected by the policy, but that even a subsidy is regressive because of the distribution of consumption of fruits and vegetables”
As they discuss, and we are finding in our work, such effects can occur through a number of channels. Take a subsidy on fruits and veggies. If richer households are already eating more fruits and veggies, who do you think receives the largest gains from the subsidy? Fat taxes are regressive because the poor spend a larger share of their income on food (so taxes take a proportionally bigger chunk of their income) than the rich, but also because they are often eating more of the foods that will be taxed and because they may be less responsive to such price changes.
The social and distributional consequences of these sorts of price policies are seldom discussed with any seriousness by those who promote the policies.