I've done lots of experimenting with what keeps me in ketosis and what kicks me out.

Of course, this is MY body, not yours, and mine is 72 and female.

Eating starch stalls me, but I stay in ketosis. Sugar kicks me out.

Whether I just slip and eat too many carbs or "sin" I get back on plan. It takes me about 4 days to get back into ketosis and a week to feel like "I'm back."