Hi Angela,
My apologies I am just getting to this post. It has not been an area I am so familiar with. But recently two names came across my desk that might be helpful. Brian Cook at the University of Oxford, as well as Sadaf Mollaei (University of Waterloo). They are both doing work on consumer behaviours and sustainable diets that might be helpful.
I also came across this open-access review on How to Effectively Encourage Sustainable Food Choices: A Mini-Review of Available Evidence. There may be some really good feedback and ideas to consider: https://www.frontiersin.org/articles/10.3389/fpsyg.2020.589674/full#B17.
In short: nudging (choice architecture) is likely to work; information provision, much less likely unless it is linked directly to a barrier or goal; people’s pre-existing values and habits mediate the effect.