Recommendations for a sustainable diet:

Prioritize plant-based proteins:
Replace red meat with legumes or hearty grains at least 3 days at a time to drastically reduce your water and carbon footprint.

Audit processed foods:
Cut out products with more than five ingredients; their industrial production is one of the largest sources of emissions and chemical waste.

Eat seasonally:
Buy only vegetables grown in your region and in the current season to avoid the energy spent on transoceanic shipping and large-scale refrigeration.

Manage organic waste:
Set up a home composting system so food scraps don't end up in landfills, where they generate methane gas.

Make the most of virtual water:
Waste less prepared food; throwing food away means throwing away the thousands of liters of water used to produce it.