Yes, you can do keto as a crash diet. But should you do it as just a crash diet? I’d suggest not. As I’ve said earlier, ketosis is a metabolic state of the body so it doesn’t make sense to get out of it, in say just three weeks.
If you have medical conditions such as kidney stone, gallbladder stone, cholesterol issues or fluctuations in liver SGOT and SGPT levels, keto is not an ideal option for you. Before embarking on this journey, it is mandatory to get blood tests done so that your body’s compatibility with keto can be assessed.