This advice is erring on the side of caution, because raw food can cause extreme bloating and gas when you have parasites. It's easier to get parasites from raw food than it is from cooked food and if you already have low defenses, you could be at risk for more. Let's say you're at a restaurant (you don't have to be in another country to get a parasite) and they leave the tomatoes out for too long, or they inadvertently use a cutting board to cut veggies that raw chicken was cut on. Your body at this moment is not strong enough to knock it out, but it should be after Phase 3.