Wouldn't adopting a balanced diet that's reasonably low in carbs plus some exercise achieve the desired effect but without fucking shit up in the process?
I can't imagine going from a sedentary, high-carb, overweight lifestyle to a radical diet(be it keto or whatever else the person chooses) is easy on the body.
Did you get any lab tests done before and after starting the diet? If you did, how did the results compare?