So if you are starting a Ketogenic WOE (way of eating) to lose weight, you would be better off not thinking like that. You will very likely lose weight but it is not a weight control thing.
By limiting net carbs to 20 or 30 grams per day, you are removing most sugar and things that your body turns into sugar. With no “easy” fuel around means that your body will have to process fats into substances called ketones that are also fuel for your body. Your body can utilize only two base fuels: Sugars and Ketones.
Changing your body chemistry to process fats into ketones takes a few days to a week or more. When your body starts processing fats into ketones, they can be detected using urine test strips. Making ketones is not the same as utilizing them for fuel. At first, the ketones will be detected in the urine but as your body chemistry becomes more used to burning them the amount of ketones in your blood and urine will decrease because they are being consumed as fuel much more efficiently than when you first started eliminating sugars and other carbs. Don’t get hung up on the test strips as an accurate way to determine if you are “in ketosis”.
Going Keto is not the easiest change you can make. You need to read every label before you buy it to check the Carbohydrate listing. If it has more than a couple of grams of carbs per serving, pass it up. You will quickly find that 99% of everything in the store has too many carbs. This means that you will have to prepare foods yourself and resign yourself that there are foods that you will never be able to eat like most bakery items, pasta, popular cereals, etc.
The good news is that you can eat all the fatty things that you have avoided your whole life. You will find that if you follow the very simple idea of removing sugars and things that your body turns into sugars, you will begin to burn fats and the cravings for sugar, cake, bread, etc. will vanish.
I have no will power so it is a pleasant surprise that I do not want to eat as often or as much as I did before Keto. I have my “Bullet-Proof” coffee and I am not hungry until two or three in the afternoon. There is no will-power involved when you are simply not hungry. I did lose weight, going from 278 to 225 and waist size from 44 to 34. Anyone can do this but change is not easy and old habits are hard to eliminate but anyone can do it but it is a commitment. You cannot do this part-time. It is a lifestyle change and not a temporary thing that you can go on and off again.