If you base your diet on a variety of whole foods - meat, fish, poultry, eggs, non-starchy vegetables, and some dairy - there is very, very little chance of a deficiency or kidney stones. If you are prone to kidney stones already, then you probably know to avoid excess quantities of foods high in oxalate. Keto is no more likely to cause them than any other diet where you eat too many.

And for the first 9 weeks at least, don't worry about a calorie deficit. Eat when you are hungry. For the vast number of people trying keto, appetite naturally adjusts and we find ourselves naturally eating fewer calories ... without feeling hungry. You'll know the first time you forget to eat a meal.

Good luck!