A few days ago, my husband suggested we do a three day fast. Fasting is easier when both of us are on the same schedule. I agreed, and our 72-hour fast starts started last night at 8:00 p.m. However, when my husband suggested the extended fast, my first thought was: “Why would we stop after getting over the hardest part?”
I’ve done a few 7-day fasts, following Dr. Jason Fung’s fasting protocol. I drank water, coffee with cream, herbal tea, and bone broth during those seven days. Every time the second day was always the hardest when it came to hunger. But the hunger always subsided the next day.
What Happens During a Fast?
In Jason Fung’s The Complete Guide to Fasting, he outlines what happens to our bodies as we begin an extended fast.
Stage 1: Feeding – We eat, and our blood sugar level goes up. The pancreas releases insulin to move glucose into cells to maintain blood sugar levels; Excess glucose is stored in the liver as glycogen or converted to fat.
Stage 2: Postabsorptive Phase – Six to 24 hours after your fast begins, your blood sugar and insulin start falling. At this point the liver taps into our glycogen stores to release glucose. We have enough glycogen to last 24-36 hours.
Stage 3: Gluconeogenesis – 24-48 hours after fasting starts, our bodies have run out of glycogen. Your liver begins gluconeogenesis, the process of creating new glucose from amino acids. This is the time where I find myself getting irritable, hungry and feel like I’m freezing.
Stage 4: Ketosis – 24-72 hours after fasting starts, your body switches to its secondary energy source (ketones, baby!). Lipolysis, the breakdown of fat for energy starts due to low insulin. Triglycerides are broken down into glycerol and three fatty acids. The glycerol takes the place of the amino acids for gluconeogenesis. And our bodies use the fatty acids as fuel, creating ketone bodies: you are now a fat burning machine.
Stage 5: Protein Conservation – Five days after starting a fast, muscle and lean tissue is maintained by high levels of growth hormones. Our metabolism is mostly powered by ketones and fatty acids. Blood sugar levels are stable due to gluconeogenesis (using glycerol). Adrenaline levels rise to help with fat burning and releasing glycogen.
These five stages describe how humans survived before our on-demand lifestyle. For most of human history, people experienced times of plenty and not-so-plenty. That’s why our bodies come equipped with a second gas tank – to survive those lean times.
I’m not advocating starvation. I am advocating the benefits of flipping the switch and running my body off that second gas tank. The beauty is that the ketogenic diet and fasting do just that. No starvation required.
7 Days or Bust!
Based on these stages, my husband and I will reach ketosis on the very day we end our fast.
I’m committed to the 72-hour fast, but if I feel great during that last day, I’ll let my husband know that I intend to keep going. If he wants to stop, that’s fine. I’ve done extensive fasts while he made his own food. I have my techniques to avoid any smells from the kitchen or being in the same room while he eats.
It’s been a while since I fasted for seven days. I used to do them twice a year and I wanted to get back to that schedule this year, including a water-only fast in the fall.
Today seems like the perfect opportunity.