The keto diet has major downsides long term. The constant use of gluconeogenis to generate the glucose you actually need for brain health plus blood sugar regulation causes in the long run over stimulation of cortisol production and causes stress to your organs and more. keto advocates gloss over this science. It is valuable therapeutically for cancer and neural damage and other risks and I would use this but not as a lifelong program. It also encourages under eating in some .(like me at 75 yo). I’m now pursuing a pro metabolic eating with good carbs and yes, fruit to have more constant blood sugar regulation during my day. Leading to more energy production. I’m over keto and low carb. Lustig did his sugar research on mice. Quite different. He’s made lots of money on those mice. Other than therapeutic use, I now know that there are cons in even keto and carnivore. I don’t trust much now but this is working for me. N=1. 😀👍🏻