After 10 months of ketogenic eating, last month I went in and out of ketosis for 5 days here, 5 days there and it was AWFUL after day 2 being out of ketosis. Some days I would binge on high carb food, and some of the days were just experiments to see if I could eat 40 carbs a day and still stay in ketosis like other people seem to be able to do. After day 3 of each carb binge I would wake up with a nearly constant headache in the morning and even ended up with a migraine, of which I had usually had 2-5 a month before keto but keto resulted in 1 in 10 months but now its 2 in 11 months because of my failed experiment. I also have felt the worst I have in months with these little experiments in eating excess carbs which also including a bout with a serious nocturnal asthma episode which I thought had almost gone away due to keto.
Its just not worth it to binge on excess carbs. It results in constant carb cravings and at least for me, painful, uncomfortable symptoms returning.