Today’s post covers a topic in nutrition that I get asked about pretty often, and I think I know why. It pretty much flies in the face of everything we’ve heard about healthy eating. You know, that breakfast is the most important meal of the day, or that we should eat 5-6 times a day to keep our metabolism running. So today I wanted to cover the basics of intermittent fasting, the benefits of the practice, and how you can get started.
what is intermittent fasting?
Intermittent fasting (IF) is a pattern of eating that changes when you eat, not what you eat. IF comes in many different styles, the most popular of which is to fast for 12-16 hours of the day, and eat all of your meals within the remaining 8-12 hours. For many, this looks like eating an early dinner and then skipping breakfast. For example, if you wrap up dinner by 7PM, you’ll have fasted for 12 hours if you eat again at 7AM, or 16 hours if you break your fast at 11AM.
Some other ways to IF:
- 5:2 method – eat normally 5 days a week, and decrease calories to 500-600 for the remaining 2 days.
- eat-stop-eat – fast for 24 hours at a time, usually 1-2 times a week
what are the benefits?
There are a lot of benefits associated with intermittent fasting, and most of them boil down to a few key things: lower insulin levels & increased insulin sensitivity, and increased autophagy. Let’s break it down.
lower insulin levels & increased insulin sensitivity
When you’re in the fed (i.e. not fasted) state, your pancreas secretes insulin in reaction to the food you eat, namely the carbs. Insulin is a hormone that tells your body’s cells to absorb the glucose floating around in your blood. It’s a storage hormone that stimulates the production of body fat when produced in excess in response to excess food consumption.
Walking around with a high level of insulin on the sporadic occasion is one thing (hello, my recent trip to LA). But if it’s happening on the reg, it can get ugly. Enter insulin insensitivity. Basically, the more insulin your body produces, the less adept your cells are at dealing with it. You become insulin resistant, which can lead to other health conditions like prediabetes or type 2 diabetes.
By fasting, or decreasing the amount of time you spend in the fed or insulin-secreting state, you lower overall blood levels of glucose and insulin. Instead of utilizing glucose for fuel, you teach your body to use other stores of energy, like body fat. And by managing lower overall insulin levels, you’re also helping your cells stay sensitive to its effects when you are in the fed state.
Autophagy is a very cool thing that your body does that you’ve probably never heard of. Think of it as your biology’s very own recycling system. Its rate is boosted by the low insulin levels associated with IF. During autophagy, our cells cannibalize themselves, eating up damaged/old/otherwise less than awesome cells, and using their parts to regenerate new ones. I know it sounds weird and gross, but it’s actually good for you. Autophagy helps control inflammation, boosts immunity, and slows down aging.
so how do you get started?
You can’t “out-fast” a bad diet, so the following suggestions come under the overarching assumption that when you’re not fasting, you’re eating mostly whole foods and lots of veggies. If you’ve got that on lock and want to see if some tweaks here and there help you feel/look/perform better, here’s how I’d tackle it.
Start slow! Your new IF routine can take some getting used to and it can be tough on some women hormonally, so don’t try to go all in during your first week. Try fasting for 12 hours a day just a couple times a week. Gradually increase your fasting days and/or your hours fasting and keep tabs on how you’re feeling.
If you’re having trouble with the fast due to hunger or a lack of mental clarity, sipping on a coffee with MCT oil may help get you to the 12+ hour mark. The MCT oil is all fat, so it won’t spike your insulin. Its also been shown to help your body’s production of ketone bodies, which will help you feel energized and focused along with the caffeine from the coffee.
And if the hunger is really getting to you, check in with your intake by logging in My Fitness Pal for a day or two. You may not be getting enough calories in during the day to keep you satisfied through your fast. Remember, IF isn’t about crazy caloric restriction.
If after all that, you can’t get down with IF, move on with your life! There are so many ways to be healthy, and this is just one of them. There’s something for everyone, but there’s not one approach that works for all.