Most people begin producing ketones within two to four days of keeping carbohydrates very low. Full fat-adaptation, where your body runs comfortably on fat as fuel, often takes a few weeks — patience makes a big difference here.

It's possible. As your body switches fuel sources, some people experience a short-lived 'keto flu' — mild fatigue, headaches or brain fog for a few days. Drinking enough water, sleeping well and paying attention to electrolytes (sodium, potassium, magnesium) helps most people through this phase gently.

Plenty. Eggs, fish, poultry and quality meats; leafy greens and low-carb vegetables; avocados, olives, nuts and seeds; olive oil, butter and full-fat dairy if you tolerate it; berries in moderation. The bigger shift is reducing bread, pasta, rice, sugar and starchy foods.

Not necessarily. Most beginners focus first on keeping net carbs low and eating until comfortably satisfied. Some people find tracking helpful for a short period to learn portion sizes, but obsessive counting isn't the goal — a sustainable rhythm is.