I usually have two meals a day, at evening and before sleep. Always after I am done with the work and training. I think the change you experience is not about

I usually have two meals a day, at evening and before sleep. Always after I am done with the work and training. I think the change you experience is not about stomach size, but ketosis. Ketones are such a great source of energy compared to glucose, that raising glucose level by eating feels like you lose something, for me, at least.