What is Intermittent Fasting, and Does it Work?

Intermittent fasting – Yo – WHAT is THAT? Should I be doing it? And if so, WHY??? Even my 14-year-old niece was telling me the other day, "it's the BEST way to eat". (Ummm. Actually – to NOT eat – right!?)

Hey SmoothiesGo Fam! Today I want to give you the low down on intermittent fasting. It is a buzz word these days – sort of like "going Keto" (more on that in another blog post). 

My fellow healthy body WORSHIPPERS, let's delve into intermittent fasting and find out if there is any real SCIENCE behind it, and what that science says about intermittent fasting and its effects on our healthy bodies!

First off, what is intermittent fasting, and how do you do it? 

It is a way to lose weight by voluntarily abstaining from eating food for a certain amount of time. There are endless variations on how to do it, but all involve alternating between periods of eating and extended fasting. Here are some of the popular methods:

• 16:8 - Eat during an 8-hour block of the day, fast for 16 hours
• 20:4 - Eat during a 4-hour block of the day, fast for 20 hours
• 5:2 - Eat as you normally would for five days a week, fast eating 500-600 calories only for two non-consecutive days a week
• Alternate day - Fast on alternate days and eat as you usually would every other day
• Spontaneously skip meals whenever you want

Is there a science to back this weight loss plan, or is it just the latest craze?

With intermittent fasting, like so many other health topics, there are conflicting views out there and confusing sources of information. A trustworthy and informative resource we like on Intermittent Fasting at SmoothiesGo is Harvard Medical School's Monique Tello, MD, MPH, who published an article in Harvard Health Publishing called Intermittent fasting: surprising update. In it, she says that her favorite resource material on this topic is a book written by Dr. Jason Fung, called The Obesity Code. I love what Dr. Fung has to say, too! Dr. Tello thinks this book is the most evidence-based summary of intermittent fasting. She said she "loved it," and that "Fung successfully combines plenty of research, his clinical experience, and sensible nutrition advice, and also addresses the socioeconomic forces conspiring to make us fat. He is unambiguous that we should eat more fruits and veggies, fiber, healthy protein, and fats, and avoid sugar, refined grains, processed foods, and for God's sake, stop snacking."

Wait. What?! Do I have to stop snacking? WHY?

YES. Because at the most basic level, this is what happens when we eat food: our bodies break down the food we eat with enzymes, and the carbs we eat, like added sugars, white flour, and white rice, are broken down into sugar, which our bodies use as fuel. If we eat more sugars than we need for fuel, insulin does its job of keeping our blood sugar at healthy levels. How does it do that? It takes the extra sugar we don't need for fuel, and it stores it as glycogen in our livers and as – you guessed it – FAT. 

On this basis, intermittent fasting makes sense. The reason for not snacking is that if we don't snack, our insulin levels can drop, and our fat cells can release their stored sugar for us to burn for energy. Yep – that is the whole notion behind the idea of intermittent fasting: we let our insulin levels drop low enough, for long enough, to get our bodies to use for FAT for fuel and BURN the fat away! How cool is that??? Ba-bye, fat!

Does intermittent fasting work?

Intermittent fasting does work! Is it easy? I don't think so. Can one keep it up? That's a good question. BUT, as Dr. Fung says, on so many levels, it is the most convenient diet there is to help you lose weight. It does not tell you what to do. It is simple, free, and flexible and requires no shopping, preparation, or clean-up! You can do it whenever you want, and anywhere you want. You can do intermittent fasting no matter what your current food restrictions might be. You don't eat gluten, nuts, dairy, meat, soy, added sugar? No problem! You don't like to cook? Excellent! You don't have money for an expensive diet? That works too!!! Simply - don't eat! And - like magic - your body will do the work for you; it will dig into your fat reserves and burn fat for fuel. Intermittent fasting is incredibly effective!

Is it worth giving intermittent fasting a try?

We think so. There is still a lot of research on human subjects to be done, but if you are healthy, there seems to be no danger in trying it! A few of us at SmoothiesGo tried the 5:2 strategy, and with the 500 to 600 calories to consumed each fasting day, we had two SmoothiesGo smoothies. For example, the Love - Strawberry Cashew smoothie has only 110 calories per serving/210 per bag, and our Power - Dark Chocolate Espresso smoothie has 170 calories per serving/340 per bag. Perfect! We also tried the 16:8 method, and we found that method more natural for us. But - remember, if you have advanced diabetes, are on medications for diabetes, have a history of eating disorders like anorexia and bulimia, are pregnant or breastfeeding, you should not attempt intermittent fasting unless under the close supervision of a physician who can monitor you.

Share your intermittent fasting experiences with us!

We would love to hear what your experiences have been with intermittent fasting. Tell us, in the comments below, how you felt while fasting, if you lost weight, how hard or easy it was for you, and how you fasted! And, if you want to see Dr. Fung talking about intermittent fasting, check out this well-rated, widely viewed video here. It is fabulous - if you don't mind a little science. 

Sources

Effect of Alternate-Day Fasting on Weight Loss, Weight Maintenance, and Cardioprotection Among Metabolically Healthy Obese Adults: A Randomized Clinical Trial. JAMA Internal Medicine, May 2017.

Alternate-day fasting in nonobese subjects: effects on body weight, body composition, and energy metabolism. American Journal of Clinical Nutrition, January 2005.

The Obesity Code, by Jason Fung, MD (Greystone Books, 2016).

Intermittent fasting interventions for treatment of overweight and obesity in adults: a systematic review and meta-analysis. JBI Database of Systematic Reviews and Implementation Reports, February 2018.

Metabolic Effects of Intermittent Fasting. Annual Review of Nutrition, August 2017.

Early Time-Restricted Feeding Improves Insulin Sensitivity, Blood Pressure, and Oxidative Stress Even without Weight Loss in Men with Prediabetes. Cell Metabolism, May 2018.

https://www.nytimes.com/2019/11/23/style/self-care/intermittent-fasting-benefits.html?searchResultPosition=1