Individuals who have followed ketogenic diets for extended periods (five years or more) can become carb-sensitive, experiencing weight gain and feeling unwell when reintroducing carbohydrates.

“so then they're like no no i feel better on low carb like no you've trashed your metabolism and now you have to heal it by eating carbs and slowly like you can start with one meal a week that have carbs in it in order to start to heal that metabolic rate again and bring the temperate body temperatures back up because it can cause serious damage”