Hi Cyn, The numbers are general guidelines but will vary depending on many factors, such as activity level, insulin resistance, weight and more. There is no single magic number, just conventional recommendations that are a good starting point. I will have a macro calculator coming soon that will help determine what is best for each person, but even then it’s an approximation. The only way to know for sure is to test. If keto is your goal, it’s usually best to start lower and then see if you can stay in ketosis when increasing.
The first modern study of fasting as a treatment for epilepsy was in France in 1911. Twenty epilepsy patients of all ages were "detoxified" by consuming a low-calorie vegetarian diet, combined with periods of fasting and purging. Two benefited enormously, but most failed to maintain compliance with the imposed restrictions. The diet improved the patients' mental capabilities, in contrast to their medication, potassium bromide, which dulled the mind.
In terms of weight loss, you may be interested in trying the ketogenic diet because you’ve heard that it can make a big impact right away. And that’s true. “Ketogenic diets will cause you to lose weight within the first week,” says Mattinson. She explains that your body will first use up all of its glycogen stores (the storage form of carbohydrate). With depleted glycogen, you’ll drop water weight. While it can be motivating to see the number on the scale go down (often dramatically), do keep in mind that most of this is water loss initially.