Meat production is using some parts of this energy (e.g. transportation of feedstock + food). You either want to look at how the energy is produced or how it is consumed.

Moreover, we aim at reaching net carbon by 2050. This means that we need to cut on everything. So the question is about how easy it is to reduce such budget and how efficient this cut provides.

In this perspective, zero waste is a bad trade off for climate change (a lot of efforts and only a 100 kg saved per year). Vegetarianism (or better veganism) sounds like the best thing to start with.