I think,
@Keith Martin and
@Joleneakamama, that you are failing to appreciate the sheer joy of discovery, and the value of learning physiology through simple experiments like this. You're taking this all far too seriously.
I recall an experiment at university, where we either hyperventilated, or breathed pure oxygen, and then saw how long we could hold our breaths for afterwards. It was fascinating and taught us a lot about respiration. Did I, as a result, decide that I should always hyperventilate, or always breathe pure oxygen? Of course not, that would be daft. But by experimenting on myself and seeing my own body's reaction to different circumstances I came to understand respiration considerably better.
Blood sugar is important to know about, including its effect on appetite, diabetes, and many other things. Playing with food and considering the body's responses to it is of immense value. Would that mean we'd find that eating dessert before a meal had one specific effect so we'd suddenly decide to always do it every day? Of course not. But the idea that a sweet treat before a meal could depress appetite is fascinating - because to understand why it might have an effect, you'd need to understand the physiology of what is going on. And that opens the door for a massive discussion on biology, that now makes sense as it is tied to something tangible (and tasty).
And just the process of science - seeing how to figure out these things - is itself of enormous value to learn, and most enjoyable to learn when doing something that is simultaneously silly and relevant to life.
This sounds like an immensely enjoyable and very silly thing to do, which has the potential to spark an interest in physiology. Hence why I seriously think it's a fascinating idea for an unschooling homeschool project.