There are some uninformed people out there--- like Jillian Michaels--- who give as one criticism of the ketodiet that people who cannot or do not exercise can lose weight on it, as well as clear up various health problems.
OK, I know that in our ignorant-of-facts culture loads of people believe that exercise somehow cures people of being fat, or punishes them appropriately for being fat. We had examples like that horrible 'Biggest Loser' show where morbidly obese people were screamed at by skinny personal trainers to keep exercising on their gym machines when they were too exhausted or in too much pain to continue, so that they could temporarily lose some weight and then gain it back.
But the fact is that you can't out-run or out-exercise a bad diet. A fat guy who buys a gym membership and 'goes to the gym' daily is just going to end up a poorer fat guy.
And there is also the fact that many people who who need the various benefits of a ketodiet cannot exercise because of health issues. Some people are bedridden or in wheelchairs. Some people have serious heart defects. Some people have chronic fatigue to the point that when they get home from work they barely have the energy for survival chores like laundry and cooking dinner. Do we really want to tell these people they just have to go die because they can't do the kind of exercise Jillian Michael likes?
I have read more that one story of keto diet success in which the person went on keto, but did not start to exercise until the ketodiet had helped them lose weight and/or gain back some energy. Is that a bad thing that these people were helped?
I think the exercise gurus/professionals like Jillian Michaels need to get off their high horse and realize you don't need to do gym exercise to be healthier! And not everyone has a nearby gym--- I think the closest one to where I live is in the next state!
A good diet (ketogenic) and getting enough exercise are two different things. And formal exercise is not the only kind of exercise--- what about people who walk to their place of work or school, or who climb up and down stairs instead of using an elevator? That exercise counts, too.
There is scientific research that shows that a keto diet is a healthy and helpful diet. Is exercise helpful? Yes, but so is wearing your seatbelt and avoiding poker games with Mafia hit men. Any form of healthier living is an improvement, and you should not have to do one thing to be allowed to do others.
A recommended book by Gary Taubes, and a not-recommended book by Jillian Michaels. I'm reading the Taubes book right now, and am learning a lot. The language is kind of technical, though!