You're definitely not alone in thinking that food affects your ability to focus. I've definitely been noticing that too. I'm also in the same boat in terms of preferring salty and spicy foods to sweet foods.

One thing that I really love for breakfast that keeps me full and makes me feel focused is avocado toast. I usually make it using a really good whole grain bread from a local bakery. I mash up half an avocado on a plate and squeeze in a bit of lemon juice. Then I toast a slice of bread and spread the avocado on top. I top it off with another squeeze of lemon juice, a drizzle of olive oil, a sprinkle of sea salt, and (very importantly for those of us who love spice) a generous sprinkle of Marash red pepper flakes... or just any old red pepper flakes if I am in a pinch. I find that it's the perfect combination of delicious and filling without being too heavy. :)

Reading inquisitively helps me to avoid skipping over indicator words like "because." In this case, when I read "The welfare state cannot be successfully implemented," my mind immediately paused and thought, "Why not?" That way when I started up again and read the word "because," it was really obvious that it was introducing a premise that tells us why the welfare state cannot be successfully implemented. I hope that helps anyone who is having this issue!