What’s the consequence of making this a right?

Just for starters, it implies certain acts intended to deliberately deprive people of access to food constitute a crime. So embargos of regions like Cuba, Ukraine, Sudan, Gaza, and North Korea would be de facto illegal under international law.

Of course, then you have to start asking questions like “What does it mean to be in violation of international law when the ICJ is so toothless?” But that’s the UN for you. Issuing generally progressive proclamations through a general assembly while a handful of economic heavyweights get to decide how it all gets enforced.