Hot Topics in Nutrition: Intermittent Fasting
Written by Rebecca Pedrick-Graybeck, Nutrition Coach at CORE57
I am excited to kick off this newest series on our blog, Hot Topics in Nutrition, where we will be highlighting some of the most popular trends in nutrition and digging into the good and the bad of “nutrition for the masses.” We’re kicking off the series with intermittent fasting - here’s your rundown on the good, the bad, and the ugly!
I’ll preface this series by saying, “I get it.” It's impossible not to get enticed by the promises of highly popular dieting and nutrition “fixes,” especially when so many people are struggling to get their health under control in our current society. Everywhere you turn, we are inundated with the latest and greatest programs to follow and things to buy that promise a quick solution, but it’s important to know the ins and outs before committing to ANY nutrition program or supplement, especially when they promise rapid results and big changes.
What is Intermittent Fasting?
In the last 15 years or so, intermittent fasting (IF) has garnered considerable attention in the realms of nutrition, wellness, and longevity. It's touted as a somewhat magic solution for fat loss, metabolic optimization, and anti-aging.
Intermittent fasting, also known as time-restricted feeding, is most commonly done by not eating for 16 hours and fitting your meals in during the remaining 8-hour window. There are other methods, but the main point is that there are parameters or rules around when you can consume calories.
How Does IF Impact Your Body?
So let's start off with why this works and who it's good for. Ultimately, weight loss comes down to net energy balance. If we take in less energy than we expend, we lose weight, and vice versa.
Putting structure around when, what, and where we eat often leads to weight loss because we now pay more attention and limit our "opportunity" to take in calories, which typically leads to lower overall consumption. Even though intermittent fasting or time-restricted eating gets a lot of fancy press in the media, studies actually show that it is not any more effective than other methodologies for reducing calorie intake.
Speaking of studies, most people don't know this, but the vast majority of studies done on intermittent fasting have been done on men and mice. Today, through the amazing efforts of some world-renowned female doctors and physiologists, we are learning more and more about the differences between male and female metabolic responses. It has been shown that IF can be more detrimental to a female's delicate physiology, while men experience much less negative ramifications and more positive outcomes.
Dr. Stacy Sims is one of these researchers, and her work has pioneered the movement to discover what works best and is truly healthy for female physiology. She explains that fasting for women, especially women who exercise, negatively affects their endocrine system.
Two primary areas of a woman's physiology take a hit with prolonged fasting. One is that a woman's body is more apt to break down lean muscle tissue first instead of fat tissue in an effort to conserve energy, whereas male bodies do not do that as readily. Women's bodies will downregulate the production of thyroid hormones as well as sex hormones, sometimes to the point of stopping ovulation.
The other area is in appetite dysregulation. Women's bodies upregulate ghrelin (the hunger hormone) and downregulate Leptin (the hormone that tells your brain you are full).
You can learn more about Dr. Sims' views on intermittent fasting in her book Next Level and in Episode 113 of Biceps After Babies Radio.
The Psychology of IF
Dr. Sims' explanation is consistent with my 15+ years of experience working with clients who try intermittent fasting. It usually works well initially, but over time, people tend to overeat during their feeding window and have a lot of trouble moderating their intake because they are simply overly hungry.
The other piece to consider is the psychology. Whether it's conscious or subconscious, it's human nature to think we "deserve" or "can afford" to eat more if we have skipped a meal or restricted ourselves in some way. In essence, we feel like we're giving ourselves permission. In extreme cases, I have seen intermittent fasting turn into a binge/restrict cycle of overindulgence because the person can't control themselves once they do start eating, then starving or restricting as a way to balance out or negate or even punish oneself. This is a very unhealthy and dangerous cycle to fall into.
IF and Fitness
It's especially important to state that intermittent fasting around workouts is not ideal for anyone, female or male. Peri-workout (the hours prior to and post-workout) is a precious time when your muscles NEED and want to have energy available to carry out the work in your training session as well as repair and recover afterward. Simply put, if you do not provide your body the necessary nutrition around your workouts, you will not reap the desired benefits of that training stimulus!
If you are in the EARLY BIRD crew working out at 5:45 or 6 am and don't feel well eating before your workout, that is okay as long as you get a good dose of protein and carbs within an hour after. If you feel like you lack enough energy during the workout or your energy tanks halfway through, something small like half a banana or half a protein drink 20 minutes beforehand would be good to experiment with.
Who Should Try IF?
Okay, now that we've discussed reasons to be weary of intermittent fasting and who it's NOT best for, we can discuss when it might be worth trying.
First, as we mentioned, men tend to fare better than women because their metabolic system doesn't react to stress the same way.
If you are a male who…
is not hungry in the morning,
doesn't work out until later in the day,
and isn't overly hungry after not eating for several hours after waking up,
go ahead and try it. Just be extra aware of your energy levels and recovery from workouts because we don't want you sacrificing hard-earned muscle tissue to see the scale go down. Remember, fueling for FAT LOSS is a different ball game than just focusing on weight loss.
The best, most proven, holistic way to "intermittent fast" is to eat in line with our circadian rhythm—meaning eat when the sun comes up and stop eating once the sun has gone down. Optimizing circadian rhythm can reverse so many lifestyle diseases that are increasingly common these days (like metabolic syndrome—insulin resistance, type 2 diabetes, high blood pressure, cardiovascular disease).
Our metabolic systems are tightly tied to our circadian rhythm, and disruption of that rhythm has negative consequences that many people don't realize. We wake up in the dark, immediately look at blue light on screens, spend the day inside looking at screens, and barely see sunlight, only to get home, watch more screens, spend more time in artificial light, and eat the majority of our calories once it's dark outside.
Our sleep quality can suffer if our body is too busy digesting food that we eat close to bedtime. Suboptimal sleep causes appetite dysregulation (higher hunger and cravings), and the cycle continues. There is increasingly compelling evidence that adopting more of a circadian eating strategy (such as an eating window of 7 am–7 pm), done correctly with a focus on whole food choices and minimally processed snack foods, can reverse factors of metabolic syndrome such as type 2 diabetes.
Trust the Nutrition Experts at CORE57
As with any strategy, each person has unique experiences and nuances. It is important to consider that ADHERENCE to whatever protocol you choose to improve your health will actually be realistic and SUSTAINABLE for YOU. It is valuable to consider all details rather than just jumping on a popular bandwagon that has been romanticized for public attention.
At CORE57, our nutrition coaching program is completely individualized and tailored to your unique physiology as well as your psychology. We can help you sift through all the most up-to-date science-based information out there to figure out what is going to ultimately work for your body!
Ready to take your nutrition to the next level? Schedule a consultation today! We are committed to helping you reach your health and fitness goals in a safe, sustainable, and personalized way. Remember, there is no one-size-fits-all approach when it comes to nutrition. Let us help you find what works best for YOU.