When we’re facing food shortages around the world, the UK will suffer before others.

Firstly, this doesn’t follow from what preceded it. States in the EU aren’t the only states on the planet that export food.

Secondly, I think I see what you’re trying to say: you think that as the planet slides into famine, the UK will be worse off compared to EU states in particular because during the slide into death, the slope will be ever so slightly steeper than some countries in the EU.