Fasting: Part 1: Why?

August 19, 2019

References: Fuhrman: Fasting and Eating for HealthShelton: Fine Art of FastingCurr Opin Onco., Longo, , HVMN,

If I told you to not eat a thing for a week or two, would you think I was nuts? Would you feel afraid and say, "I can't do that!". Those were my thoughts. I write this column for me to learn and to share with you. Prepare for a mind-bending trip of discovery. This idea works. I want to do a deep dive and learn it.

Joel Fuhrman is one of America's most respected functional medicine doctors. He is widely read with his many books and has a very active research and clinical practice. With that in mind, did you know that he was a world-caliber ice skater? In that career, he had a "career-ending injury" and had an orthopedic surgeon give up on him, telling him he would never skate again. He refused to take part in a program of experimental, unproven surgery opting instead to follow Dr. Shelton's idea of fasting. He embarked on a 40 day fast, got better, came in 3rd in the World's Men's figure skating. Not bad for fasting. That intrigued him so much, he went to medical school. He found medical school all about giving drugs, not healing. Fasting? You kidding? So, what goes on in fasting? 
We've learned from Longo in prior columns that your body turns on two sets of genes when you reduce calories: RAS and PKA. You can call them your vacuum cleaner and your stem cell engine if you want to understand their function. It's primarily glucose and protein that cause trouble, in part because they turn on insulin.

Aha! Turning off insulin. How do you do that? In essence, you have to stop stimulating its production. You have to stop eating glucose and protein sources. Longo does that by cleverly making an 800 calorie diet based on nuts and green vegetables. That is an 80-90% fat diet when you consider that green vegetables get converted into fat (beta-hydroxybutyrate is the short-chain fatty acid made by the bacteria in your colon when you eat green, leafy vegetables.) You can get beta-hydroxybutyrate (BHB) from eating greens or coconut oil, or by burning your own fat. How much fat have you got to burn? Well, most of us are at least 20% fat if we are slender and up to 50% fat if we aren't. Take me at 210 pounds: 20% is equal to 40 pounds of fat. Forty pounds at 3500 calories per pound is 140,000 calories. At 1800 calories a day in fasting mode, that's 77 days worth of calories. 

But why the fast need? Ah! Here's the rub. Most of our modern diseases are caused by the immune response to our food. 70% of our immune system is around our gut. Our immune system has to spend most of its energy policing what we eat and the effect it has on us. Our gut interface is the primary boundary between us and the outside world. When we eat food that sets off our immune system, we make immune responses that are often dysfunctional, attacking us. We call those diseases "auto-immune". When we fast, we first of all remove the foreign proteins that are setting off the immune response. But more importantly, we give our system a chance to turn on your "vacuum cleaner". Our system has to clean up old, unused stuff, and knock off dysfunctional, sulking, bad-assed immune cells that are causing trouble. That's effectively what you do when you fast. 

Let's just summarize that and then move on to other topics like exactly what can fasting do for you. When you fast, you switch off the engine of foreign proteins that drive your immune system to distraction with an overload of wicked things. You switch your metabolism from running on glucose to running on your own BHB (the ketone beta-hydroxybutyrate). Your brain can't run on fat, but it can run on BHB so you don't have to have carbs or glucose for your brain to function just fine. Fasting can give you a giant reset button to push. 

At the 30,000 foot level, you turn on the conversation between your nucleus and your mitochondria when you fast. Exercise does that too. And growth hormone naturally does that. Being young is nice because you made growth hormone for free then. Over 40 and you simply aren't making it any more growth hormone that isn't suppressed by somatostatin. But this column is about fasting. Yes indeed, you are waking up the vibrant conversation between your nucleus and your mitochondria to get into shape when you fast.

It's not starving. It's fasting. Yes, you lose weight. Yes, you reduce calories. Yes, you feel hungry for the first two days. But then you have a period of time in which your body heals, resets, rejuvenates. Next week, just what!

WWW: What will work for me. I've been doing the fast mimicking diet for 18 months now. Every month I go 5 days at 800 calories. I am used to it now and confident that I switch into ketosis in 48 hours. I measure my BHB and can prove it. I also am confident that it only takes a tiny dose of glucose or protein to subvert that. I'm curious about what else is possible. I've ordered Shelton's book and am going to read that too.

Pop Quiz

  1.  An average skinny person can fast for how many days before they use up all their fat stores? Answer: Probably at least 40
  2. What good things happen when you fast? Answer: You turn on your internal stem cell engine, your internal vacuum cleaner and you fit into your old jeans. Your immune system has the time and energy to fight the right fight instead of being distracted by all that stupid food you eat.
  3. Do you feel hungry when you fast? Answer: Well, yes, for the first day or two but then you slip into ketosis and run on your internal fat stores, which your body loves to do.
  4. Most of our modern diseases are caused by? Answer: the wrong foods we so cheerfully eat.
  5. What single thing can I learn from this column? Answer: start by eating more vegetables every day. Cut one serving of meat and one serving of bread in exchange for a real food grown in real soil.