I don't know about the glucose ... ... but burning out can really destroy your life. I know it destroyed mine. It took me years to recover, and I'm still not 100%. I started working for an early stage startup right after school when I was 19yo. I didn't sleep. I didn't eat properly. Our team was small. Responsibilities super high. And I burned out. Oh, I have so many stories from this time... like when I hadn't slept…
During my early 20s, like you, i was working at a startup and had super high workload. Definitely burned out a few times but the motivation was high and i enjoyed every minute of it.
It pushed me beyond my limits and i learned so much in a very short time period.
Now, i'm closer to my 30s i don't think i could do this again. But with time comes wisdom and instead of high energy/high workload i choose to work smart/not hard.