You may start seeing weight loss very quickly. However, you won’t get into ketosis right away.
I’ve experienced some clients (who test themselves) begin to slip into a ketogenic state in under a week. But, usually, it takes up to 14 days. That said, once someone stops eating sugar and diminishes carbohydrates, they drop weight. Several factors contribute. A drop in muscle glycogen, a drop in the amount of stored water and some fat used as energy. It accelerates after 14 days of consistency.