This is a stupid argument. If you stop eating whatever way helped you to lose weight and go back to the way before you'll gain weight back no matter what diet you did.
Your kind of cretin argument is so flawed because the person who lost weight on keto got fat before and that is why they started keto.
So to sum up your small brained thoughts, if you eat a high calorie diet and gain weight, cut calories and lose weight then as soon as you eat high calories again you won't gain weight because you didn't do keto. Great stuff.
The brain runs very well on ketones so maybe you should feed your brain and start keto and that way you won't talk such dribble.