Hi! I had one experience with a cheat meal while on keto that was pretty bad. I went to brunch with family after being keto for 2 months, and I ate a stack of 3 pancakes with syrup and bottomless mimosas. I had the stomach ache of my life when I got home. I just laid on the couch all afternoon feeling sluggish and slightly nauseous.
Any other time I’ve cheated I ate smaller portions than my mishap above and was able to go about my day and bounce right back.
My advice would be to take it slow, drink lots of water, and enjoy the memories 