Also, just wanna clarify and add a few things:

Protein is the most important thing when you eat. Fat is also good for you, depending on its composition and heating (avoid soybean oil! highly heat-refined polyunsaturated fats are carcinogenic and they make you feel like shit). Carbs below around 30 grams per day is essential for being in the ketogenic state, which is the fasted state (though that number varies by person), and you wanna get the most protein-rich whole foods you can find within that guideline, whether the assortment is piscetarian, meatitarian, vegetarian, vegan, or omnivorous.

Omnivorous or carnivorous diets are easiest to maintain on keto as far as I could see, but once you find what works for you, you're golden. You can be vegetarian and eat hard boiled eggs and spinach every day if you wanted to, or go vegan, every day eat a salad of high protein vegetables and mushrooms tossed in olive oil and vinegar with a sugarfree Red Bull as a supplement for water soluble vitamins, or instead of Red Bull, nutritional yeast as your supplement. Sprinkle that shit on everything! I varied, ate some of all of this. Some days I had nothing but In-N-Out meat patties. It was cheap, easy, and had all the nutrients I needed.

Also you can keep doing keto indefinitely if you want. Just always eat when you are hungry. It's impossible to overeat on keto, and your body is right when it says you need to. Ketogenesis is like a metabolism recalibration. All of your senses will indicate real needs. If you customized your cronometer targets based on accurate data about yourself and scientific studies (the defaults are pretty good too, just adjust your macros!), then you will see that your cravings are almost always in line with what cronometer says you are missing, nutrient-wise. It's pretty cool.

In order to build muscle like I did, you must work out. You might lose muscle if you don't eat enough protein during this or if you are sedentary. It's not any easier to build muscle on keto, aside from the effect of having more free amd stable energy to be able to work out. Bring a keto-aide for workouts. You need water and electrolytes (salts). One good salt supplement is LMNT.

To really understand this stuff and get the most possible benefit out of it, do research on how the metabolism and ketones vs carbs work. Insulin to glucagon ratios are key in understanding it. Do your own research on optimal levels of protein and fat, and how much carbs will trigger a switch to low glucagon/high insulin. Do your own research on different kinds of LDL cholesterol, which the medical industrial complex still pretends are all the same. Remember there is a shitload of misinformation out there from random idiots and the medical industry alike. DietDoctor and Hava are the only sources that readily come to mind that I trust. There were only a few other sources that had a clue what they were talking about, and only in certain specific areas. You have to reason it out. Ketogenic state is great for your health in a lot of ways, and the details are fascinating.