That's my understanding. Also, as someone who suffers a lot of nausea from a medical condition, I find that if there's a lot of food in my stomach I'm much more prone to actual vomiting if I get really nauseated. Now for me, it's also the same if I'm super hungry. Being hungry can trigger nausea for me. So if I ever were to do this method, I might eat a few crackers at some time before. But that is me taking a calculated risk because I know my propensity for vomiting, and I'd want to avoid it. I am risking that the few crackers will be insignificant in the final equation, but it is much less risky than taking my chances that I won't vomit or start dry heaving because my stomach is empty. So I feel it's still OK, if you fully understand the method, to make decisions that reflect your own history and medical situation, but you must be clear that you know you are deviating slightly and accept some small risk of failure. In my case, knowing this, I will prepare 2 portions if I use this method in the future.