Intermittent Fasting, or "IF," has exponentially increased in popularity in the last couple years and has reach snowball intensity lately. Everywhere I look, someone's touting the benefits of IF with claims of weight loss, decrease in inflammation, improvement in cardiovascular health, and more. So, what is intermittent fasting? IF can mean eating only every other day (not doable for many people) or eating only within a certain window of time (ie: 10am to 6pm or noon to 4pm, etc.). In a nutshell, it's periods of eating and periods of not eating. It means not eating 'round the clock or snacking all day without end. It means giving your digestive system a chance to chillax.
Back in the 1970's, we called this "normal eating patterns." Well, not so much the eating only every other day, but having a large number of hours between dinner and breakfast was pretty common, at least in our household. I don't recall many people eating at 10pm or 2am. Maybe I just wasn't paying attention. I was in elementary school and far more concerned with exploring the forest behind my house than with the eating patterns of my fellow suburbanites. I do remember when my father decided that dinner would be at 4pm on the dot and my mother happily complied. That was our normal. Evolutionarily speaking, food wasn't available to people 24/7 and so IF was just a normal nameless part of life until pretty recently on the timeline of humanity.
"Fasting also makes sense from an evolutionary standpoint, he [Mark Mattson] says. All-the-time access to food is a relatively new phenomenon in human history. Back when sustenance was harder to come by, “natural selection would have favored individuals whose brains and bodies functioned well in a food-deprived state,” he says." - Mark Mattson, chief of the Laboratory of Neurosciences at the National Institute on Aging and a professor of neuroscience at the Johns Hopkins School of Medicine [link]
"We have evolved to be in sync with the day/night cycle, i.e., a circadian rhythm. Our metabolism has adapted to daytime food, nighttime sleep. Nighttime eating is well associated with a higher risk of obesity, as well as diabetes." - Monique Tello, MD, MPH [link]
So, how do we apply IF in a doable manner?
Eat healthfully to begin with. Cut out the fake food: avoid refined sugars and refined grains. Eat fresh, raw organic fruits, vegetables, beans/legumes, gluten-free whole grains, proteins from grass-fed animals and healthy fats (extra-virgin olive oil, grass-fed butter, avocado oil, avocados, organic nuts/seeds).
Don’t snack between meals. Allow your digestive system time to rest and cleanse itself via the MMC (Migrating Motor Complex). The MMC is a fantastic cleaning mechanism for the GI tract that can only happen when we're not busy digesting food. That clean sweep helps keep the small intestine clear of unwanted bacteria and food particles which can have a tremendous impact on our health.
Eat dinner as early as possible. For me, 4pm is the golden dinner time. I typically eat breakfast between 9 and 10am, giving me 17 to 18 hours of "fasting" if I have dinner at 4. This eating window allows enough time between meals for complete, "clean" digestion and maybe even to sneak a cleaning wave in. My breakfast 95% of the time is only fruit, which leaves the stomach in an hour or less (outside of impaired digestion). Lunch is noon or 1pm, and dinner preferably at 4 (although it doesn't always work out that way; I do the best I can). With so many hours between dinner and breakfast, I'm getting several cleaning waves in, and I notice my weight stays pretty steady, even when I'm cheating by overindulging on homemade granola.
For those eating only one meal per day, please reconsider. In order to get adequate calories in one meal, you're likely stretching your stomach beyond a comfortable point and interfering with proper digestion. A stuffed stomach does not easily digest food.
Intermittent fasting may be an easy way to implement a heathy habit into your life. Start by simply leaving 12 hours between dinner and breakfast (if you have dinner at 7pm, hold off on breakfast until 7am) and slowly try to increase that "fasting" period to 14 hours, or even 16 if you feel well during that eating window. Remember, as with any eating pattern, choose real, whole foods.
Fun fact: Thomas Jefferson ate only two meals per day; one in the morning and one in the afternoon. He was the IF boss!
As Michael Pollan says, "Eat food, not too much, mostly plants."