I once heard a story that a group of Native Americans used to make jest of english settlers by saying "it is time to be hungry now!". There's nothing magical about eating 3 times a day, but we often sit down and eat those meals even though we aren't hungry. It's how we were taught, but not necessarily how we evolved.
Only for the past 100 years or so have we had constant access to food on a day to day basis. Fasting is practiced in many different religions for various reasons. Yet the general consensus is that fasting is dangerous, that it will lead to eating disorders or health problems. While that is certainly true when taken to the extreme, could these ancient rituals have additional benefit besides just increasing mental fortitude?
We no doubt had periodic gaps in between meals during our evolutionary history, as wild animals do today.
Human beings are now in a constantly overfed state, with the main source of energy coming from carbohydrates. Upon digestion, these carbohydrates are converted to sugars. The body then produces insulin to store the sugar as glycogen. The insulin spikes eventually turn to a crash which causes extreme hunger and the process starts over again. This is also the reason for that 3:00 crash that "5-hour energy" uses to market their products. Expecting you to turn to an energy drink, which ends with another crash. It doesn't have to be this way.
I'd like to turn to some current research from Dr. Valter Longo, a member of USC's Biology of Aging program as well as the director of the USC Longevity Institute. Dr. Longo has been experimenting with Fasting Mimicing Diets or FMDs as a tool to slow the aging processes. He has shown that fasting up to a period of 5 days can clear out up to 40% of damaged white blood cells, which are restored to capacity within a few days of refeeding.
He has also shown that fasting triggers a repair procedure on damaged myelin in the brain stem, which theoretically can prevent or reduce dementia. Myelin is a fatty sheath covering the nerves that insulates and speeds up neuronal activity.
During a fast, the organs shrink due to reduced demand from the digestive system. The organs used for detoxification (mainly the kidneys and liver) finally have a chance to catch up. This seems to allow the body to activate repair processes, instead of putting most of its energy towards digestion.
Fasting also puts the body into Ketosis, after the body runs out of glycogen (sugar). Glycogen is what most people use today almost exclusively for energy weather through refined sugars or carbohydrates. Ketosis uses the liver to convert fat into ketone bodies (thus the name). A Ketogenic state has been shown to prevent seizure and treat epilepsy, starve some forms of cancer (many of which live on sugar), and reduce inflammation through beta-hydroxybutyrate or BHB. BHB blocks a set of genes known as NLRP3 inflammasome, previously linked to Alzhiemers, heart disease, metabolic disease and macular degeneration. Inflammation is related to a host of different diseases and plays a role in the aging process.
Fasting isn't the only way to get into Ketosis, thus you have the Ketogenic diet that is gaining so much popularity. It is very similar to Dr. Valter Longo's Fasting Mimicing diet. The concept is that you don't take in any sugars or starches, but focus more on vegetables and fats and a small amount of protein. Too much protein can kick you out of ketosis through gluconeogenesis, where your body manufactures sugar from the protein. Keeping low protein with no starch eventually forces the body into using the Ketogenic pathway for energy.
It's best to take it slowly in this endeavour. I wouldn't recommend a sudden switch to a Ketogenic diet from years of eating bagels and Twinkies.
Some people experience what they call the "keto flu". This is a 1-2 week period where their body is adjusting to ketosis. During this, flu like symptoms appear, along with headaches, low energy, and a dip in performance in the gym. After sticking it out though, endurance is greatly improved by being able to utilize fats for energy instead of relying on sugars exclusively. This is the body's factory setting, which will become evident when you realise blood sugar is normalized. Hunger may come, but it subsides within literally seconds as your body transitions smoothly over to stored body fat as fuel. This makes fasting or skipping a meal effortless, increasing the ability to burn unwanted fat with ease.
The best method is to take it gradually, stepping down carbohydrates (especially from grains) little by little and adding in vegetables, healthy fats and fatty cuts of meat in their place. I recommend Mark Sisson's Primal Blueprint 21-day program to get a head start on building the metabolic machinery to burn fat as fuel.
You can find all the details at: www.marksdailyapple.com