Intermittent Fasting Can Help You Live Longer!

December 30, 2019

ReferencesNEJMHarvard Health BlogNewsweekCNNLongoNutritional MetabolismAnnual Review of Nutrition,

We have tons of evidence that fasting works well on longevity in animals. There is proof that reducing calories 30% makes chimpanzees live much longer. Rats having their calories compacted into short time periods lose weight, while those same calories spread out make for weight gain. Now the prestigious New England Journal of Medicine is weighing in with a review of the evidence for fasting. What an article for New Years!

The idea is simple. They define intermittent fasting as daily structure of calories, not weekly or monthly. Compact all your calories into 8 hours a day, better at 6. Don't eat breakfast and hold off lunch till two. The alternative schedule is to cut your calories two days a week to 500 calories. These ideas are close to Longo'sresearch that looks at the generation of stem cells in addition to weight loss. What is now new is the world is waking up to the idea. It is going mainstream. In fact, it's making headlines in America's #1 medical journal, the New England Journal of Medicine.

All the major news outlets covered it this week and considering New Year's Eve coming up and everyone in America feeling fat, it's a good topic. The explanation they give is clumsy so let me give you the easier to understand concepts again. The key is how to make the transition from burning carbs to burning fat painless and easy so that you don't feel famished, and fail. How can you diet and not be hungry? You have to eat in a fashion that doesn't lock up your fat cells. It's all about insulin.

Here goes! Your body can only store about 1500 calories of carbs. We call that storage form of carbs glycogen. 1500 calories is about 12-16 hours of energy. When carbs are around, they are your preferred fuel. When you eat 3 meals a day, spread over 14 hours, you are always running on carbs, thereby secreting insulin and never turn on the genes and enzymes that help you burn fat, which require insulin to be absent. You keep invoking the release of insulin which blocks the transition to running on fat. Insulin blocks ketone formation for about 24-36 hours every time you stimulate its release which can be accomplished with as little as three french fries, a mouthful or two of rice, half a piece of toast or one chocolate bonbon out of the Christmas box. I've shown its effect on me with 1/12th of a honeycrisp apple. The bigger problem with teasing insulin is that you get starving, I mean STARVING hungry if your 1500 calorie tank drops below 750 and you are in "carb mode". You can't beat that. You feel like you are going to die. So you fail.

But running on fat isn't hard if you turn the genes on that help you make fat. The key appears to be eating foods that don't touch insulin and instead, make short-chain fatty acids called ketones. The ketone called beta-hydroxybutyrate (BHB) is the kingpin. And the biggest advance in understanding weight loss is knowing that green vegetables are digested by the bacteria in your gut into BHB. Green vegetables are thought of as carbs, but they are really secret fats because they get digested into BHB in your gut. BHB is only 4 carbons long but it is called either a ketone or a short chain fatty acid. But it has no impact on insulin. Nadda. None. Zip. Nope. Nuttin! All that is left is waking up the genes and enzymes that help you run on BHB. That is the key to weight loss.

A 14 hour fast will have you making BHB at a level of 0.1- 0.5 guaranteed. Every time. If you do it daily, you get it daily for 2-3 hours. For 2-3 hours you are burning fat, losing weight and invoking all the genes to help you do it better the next time. A 16 hour fast will do it more. An 18 hour, more. It's pretty satisfying to see the mainstream NEJM finally write a review on it. It's basic mammalian physiology.

But if you are going to to to all that bother, add the foods that propel you to make more BHB on its own. Don't eat any old calories when you eat. Focus on getting JUST green, above-ground vegetables with fats that easily break down into BHB. Olive oil, coconut oil, macadamia, walnut or avocado oils if you want to be fancy. Longo's formula is to have a 50:50 mix of vegetables and fat, mostly from nuts. But Longo's is more ambitious than just weight loss. He is after resilience and the restoration of stem cells. That takes 5 days in a row of eating no food that stimulates insulin. 18 hours just doesn't do it for stem cells. As least not that we are aware of yet.

Without insulin, your fat cells open wide open. You get all the calories you need flooding out of your pudgy, mushy, wicked, greedy fat cells. Let it go. It's called real weight loss! Yippee. Freedom. You don't feel hungry. You do feel cold because your metabolism will slow some 30% for discretionary stuff like body temperature. You can put on a sweater or a blanket. It's a new feeling, though. It's not hungry. I call it "hollow". I sure can eat. But I am also able to resist. And that leads to success. Weight loss. Mental clarity. Resilience. Stem Cells. Ha!

WWW: What will work for me. I'm doing it this week. Join me. 800 calories for 5 days. I measure my ketones twice a day with a Ketone Meter called Keto-Mojo. It's easy to learn how to use. Costs about $ 1 per test but motivates me as it's never more than 6-8 hours in the future that I'm going to measure it again. It is very satisfying to watch it rise. And any time I cheat, I can see the impact on the next time I test. Like when I ate my 1/12th of an apple and 12 hours later my BHB was half of what it should have been. That tiny bit of sweet made me squirt out a tiny bit of insulin. But insulin is so potent, it suppresses ketones for up to 24 hours.

Pop Quiz: 

  1. To lose weight, you have to teach your body to run on what fuel? Answer: ketones, or short-chain fatty acids. BHB.
  2. You make your own BHB when? Answer: When you are burning fat as fuel instead of carbs. (That's called weight loss). And when you eat green vegetables: that's called smart eating.
  3. Can I get BHB from food sources? Answer: For sure! You can pay through the nose to buy it as a supplement. Shark Tank was all in on investing in BHB startups last year. Or, you can have Bulletproof coffeefor breakfast every day, or coconut oil.
  4. What happens if I get weak in the knees and sneak in a tiny chocolate that I got for Christmas? Answer: Your body rejoices and squeals in glee. You put out insulin and your fat cells slam shut for the next 36 hours. 6 hours later you are starving hungry. It's a very balanced, nuanced switch. Like a tiny transistor on a microchip, your endocrine system is mind-bogglingly delicately balanced. Bummer.
  5. Why is BHB so important? Answer: It is the entry compound into the electron transport chain. That means it is central to energy metabolism. That means it is more important than simple carbs. It's what every animal that eats plants uses to run its energy supply. Foundational. Made by the bacteria in our gut when we eat green vegetables.