It wasn't so much negative on fruit, it was just the fact that the brain runs so much better on ketones, and the only way I can experience that more consistently is by eating less fruit. I think I am already in ketosis much of the time, except when I do eat a big serving of fruit, and it's like I can feel the energy supply being shut off afterward. My mood dips, my brain is foggier and I feel physically colder.
