I lost 40lbs on keto and after the first week of keto flu, I felt great. No sugar crashes, no energy level drops and overall, more energy than usual. I stopped after six weeks as I couldn’t deal with the lack of flavour and texture in the food I was eating. I reached a good weight that I’ve maintained, 7 years later.
One thing it taught me, was to reduce the amount I eat and to balance things out if I eat more carbs than usual.