Why is it that ketosis is deamed bad in the medical field when it comes to fitness but it's widely used for adolescent epilepsy?

Extremes: Ketosis is often taken to extremes with complete avoidance of carbohydrates, like those in vegetables, and over-indulgence in fat and grease. If it is done responsibly, with adequate water intake, vitamins, lower carbohydrate vegetables, low fat proteins like lean meat, fish & poultry, it can be a tremendous help with weight loss & epilepsy. Watch for constipation. Up water & veggies if necessary.

Need: If a form of epilepsy will not respond to regular medications (there are many) you look to anything that works to give these patients a chance to improve their quality of life. It is also not anyone's first choice.