Due to many different genetic and lifestyle factors, every individual will have a unique journey to ketosis. Some may get into a deep ketosis in 3 days, while others may not be in ketosis until a week after starting the ketogenic diet. Some may have no side effects, while others will get flu-like symptoms called the keto flu.
So, as with any journey, let’s prepare for the worst so that you can feel your best no matter what happens. First, you must understand what your body is going through, and then we will figure out what to do about it.
Phase 1 — The Glycogen Depletion Phase — 6 to 24 hours after starting the ketogenic diet
During this phase, most energy is provided by glycogen. Due to the lack of dietary carbohydrates, insulin levels start dropping, causing more water and sodium to lost in the urine than usual. Some people may experience mild dehydration symptoms like dizziness and fatigue.
Phase 2 — The Gluconeogenic Phase — ~2 to 10 days on the ketogenic diet
During this phase, glycogen is depleted, and gluconeogenesis takes over to provide the body with energy. At this point, so much water and sodium are lost that many people experience flu-like symptoms if they don’t replenish their fluids and minerals. The window of time for this phase is so broad (two to ten days) because it depends on many genetic and lifestyle factors.
Phase 3 — The Ketosis Phase — ~3 to 10 days on the ketogenic diet
This phase is the phase you want to be in on the ketogenic diet. It is characterized by a decrease in protein breakdown for energy and an increase in fat and ketone use. During this phase, ketones can supply up to 50% of your basal energy requirements and 70% of your brain’s energy needs. Depending on many genetic and lifestyle factors, it may take you anywhere from 3 to 10 days to get to this phase.
There you have it — the stages that everyone goes through before reaching ketosis. If this is too sciencey for you, think of this process as being synonymous with the adjustment period we go through after ending a relationship with someone we love very much. It takes time to move on to dating other energy sources and just like after ending a long-term relationship, breaking up with carbohydrates can cause a laundry list of symptoms called the keto flu.