Just like so many diets or ways of eating, there is a ton of information floating around about Intermittent Fasting (IF). People on the internet tend to be loud proponents of what worked for them, urging others to do the same exact thing. Their confidence can lure anyone in, especially someone who is looking to make some body composition changes. Nutrition coach Sarah Cook shares what her personal experience was when she tried to implement an IF strategy for a three-week period.
There are several methods for fasting, a common one being fast for 16 hours a day and have an 8 hour window to eat. This could look something like don’t eat from 8pm to 1pm, then from 1pm to 8pm eat to support energy needs. This is considered the 16:8.
Some benefits of intermittent fasting include weight loss (if there’s also a caloric deficit), insulin sensitivity, preventing brain aging, and increasing cellular energy production.
It can also drop blood sugar significantly, could negatively impact reproductive and hormone health (ladies), poor athletic performance, is not necessarily realistic long term and not optimal for someone who struggles with disordered eating. The evidence to support this nutrition strategy is still in its infancy.
Who is it for?
Some of you think about not eating for 16 hours and immediately think “NO WAY!” Then there are some who are intrigued. As with any diet approach where the goal is dramatic change, it is necessary to first have spent adequate time developing healthy habits, proper blood sugar regulation, effective stress management and time at maintenance calories. Essentially your body needs to trust you. Sounds funny right?? By this, I mean your body needs to know that you are going to give it what it needs for survival. Chronic dieting and such can make your body being uncertain of what will happen next. This will wreak havoc on your hormones! And if you go a long period of time without eating, this could cause your blood sugar to drop. When your blood sugar levels drop dramatically, cortisol (a stress hormone) rises, which in turn causes the blood sugar to lift in order to normalize the instability. Ideally, we do not want to do things that radically increase cortisol production and stress your body. This means that intermittent fasting can actually create more stress on the body by fluctuating blood sugar levels too dramatically. So first and foremost, before diving into intermittent fasting or calorie restriction, we would gain control of blood sugar levels and create a healthy relationship with stress and food. This can be hard for people, especially those who are known to yo-yo diet and are seeking quick immediate results. It can take time for your body to establish a new norm and “trust the process”.
So I dabbled with IF for about 3 weeks. Why do you ask?? Because I was curious and although I love breakfast, I prefer to eat my first meal around 9-10am, so I figured a few more hours fasted couldn’t hurt, right? I stay pretty busy most mornings so putting off eating wasn’t necessarily hard, although I was HUNGRY. Many days I had a mild headache until I actually broke my fast and felt a slump in energy throughout the day. Most people doing IF would tell you that after a little time most of these symptoms subside as your body adjusts. Mine really didn’t. Then something happened. I had what is known as a reactive hypoglycemic response once I broke my fast (sweating, shaking, hunger, thirst, headache, heart racing). Thankfully eating some fast acting sugars helped my blood sugar regulate, but I was left feeling pretty crappy for the day (I had to lay down and nap—which NEVER happens) and had a mild “hangover” the following day.
Some things that are important to know about my present situation. Usually one day a week, I am up early to coach a CrossFit class, get a workout in after, have a personal training client later that morning and might typically eat something light until I am back home from the gym. In this instance I had two days in a row of the same situation outlined above and once I finally ate my insulin response was extreme. For me, less sleep, high intensity training and delayed eating did not mix well (It was too much cortisol for my body!!). It is important to note that I did not change any of my other eating habits, only the timeframe in which I was consuming my food.
To course correct, I went back to my normal eating habits, which includes well balanced meals throughout the day. I am glad I experimented because I learned that although there are researched proven benefits to IF, each person’s individual make-up and lifestyle are huge factors to consider when looking at IF as a way of eating. For me, putting off “breakfast” until later in the day was not a recipe for success. I am thankful that I tuned into the signals my body was sending me and realized that this strategy is not one that fits with my lifestyle and goals.
In the end, IF is just one approach, among many effective ones, for improving health, performance, and body composition. What do all of these approaches have in common? They control energy intake, focus on quality food and encourage regular exercise. For this reason, it’s equally plausible that eating fewer calories than you burn, limiting processed foods, consuming fewer chemicals and pollutants could offer the same benefits as IF or even better ones.