What is Intermittent Fasting and Should I Be Doing It?
I’m always skeptical about the latest fad diets, but I have to admit I was very curious when I learned about intermittent fasting (IF) a few years ago. Unlike diets that tell you what to eat (or more often, what not to eat), intermittent fasting focuses on when to eat. And as someone who loves to eat and with particular food preferences, this approach was appealing to me. Also, while intermittent fasting became popular as a way to lose weight, I was intrigued by the research that showed significant potential overall health benefits including healthy aging, lowered blood sugar levels, balanced hormones, and increased mental clarity. So I gave it a try!
There are many different ways to do intermittent fasting and as I see it, these methods fall into two main categories – fasting and time-restricted eating (TRE). In the fasting category, there is the 5:2 method of eating regularly for 5 days and then not completely fasting but going into a big calorie deficit on the other 2 days per week. There is also whole-day fasting, where you eat one time each day with a 24 hour fast in between these meals. And then there is ‘alternate-day fasting’ where you fast every other day and on the fasting day you can still eat, but you significantly restrict your calorie intake.
The other type of intermittent fasting falls under the category of time restriction where you eat every day, but eating is limited to a certain number of hours each day. In this method, you choose an eating period of usually 8 -12 hours each day. During your eating window, you can fit in two, three, or more meals. An example of time-restricted eating is if you choose to eat all your food for the day in an 8-hour period, such as from 10:00 am to 6 pm, and the remaining 16 hours each day are the fasting period, during which no calories are consumed.
Research has demonstrated some significant benefits for those struggling with weight loss and chronic health problems when following a time-restricted eating regimen, especially one that has an eating window earlier in the day. These benefits include:
Decreased appetite and increased fat metabolism
Prevention and reduction in the occurrence of diseases such as neurodegenerative diseases, type 2 diabetes, and some types of cancer
Blood insulin reduction
Reduction in blood sugar level
Lower blood pressure
Decreased inflammation of cells
Lower insulin levels
Lower levels of ghrelin, an appetite-stimulating hormone
Improvement of menopause-related health symptoms, including weight gain, insulin resistance, mental health changes, and brain fog
After doing my homework, I decided to try time-restricted eating (TRE) with an 8-hour eating and 16-hour fasting window. I was going to start eating at 11:00 am and finish by 7:00 pm. I chose this method because unlike intermittent fasting, which involves caloric restriction, time-restricted eating allowed me to eat as much as I wanted during the eating window and seemed to best fit with my diet preferences and lifestyle. Time-restricted eating also aligns eating and fasting cycles to the body’s innate 24-hour circadian system, which made sense to me.
That was over 2 years ago, and since that first day, I’ve been doing some variation of time-restricted eating almost every day. Here’s what I experienced and some common mistakes that people make when adopting this kind of eating pattern.
Delaying my first meal until 11:00 am was fine on some days, but on others, I was watching the clock and occasionally got hangry. I’m an early riser, and often 6 hours of activity would happen before the start of my eating window, which was sometimes just too long for me.
Limiting your eating window is not a free pass to eat whatever you want! I still needed to make healthy choices. If you eat too many calories whether it is during a 14-hour eating day or a 6-hour eating day, you will not lose weight. So that entire bag of tortilla chips, a big container of guacamole, and a chocolate bar was still not a good idea even if I ate it all during a limited eating window! Once I figured this out and went back to my typical foods, I lost a few pounds.
Beverages (other than water, natural tea, and black coffee) will break your fast. If you put cream and sugar in your coffee at 7:00 am, but delay breakfast until noon, your eating window started at 7:00 am.
It’s important to stay well hydrated by drinking enough water during your fasting window.
Ideally you want to match your eating window with your circadian rhythm and daylight hours, so that you are eating earlier in the day rather than later. Research shows that this is the optimal way to do TRE for weight loss and controlled blood sugar levels. Limiting late night eating is also better for a more restful night’s sleep.
Today, my intermittent fasting routine still exists, but in a different form from when I started 2 years ago. My eating window has expanded to about 10 hours most days. I still finish eating for the day by 7:00 or 7:30 pm, but I usually have breakfast around 9:00 or 9:30 am. Breakfast and lunch are my bigger meals and dinner is small. When I started IF I was a bit obsessive about it, planning my mealtimes and worrying if something was going to interfere with the timing. Now, I go with the flow, and on the days that it works, I feel great, and on the days that it doesn’t, I know that I’ll be back on track the next day, and overall, this pattern of eating is easy for me and I am on track most of the time.
Time-restricted eating has become a part of my diet and lifestyle that feels very natural, not at all restrictive (despite the name!), and I have noticed some health benefits (although mine is certainly not a proper experiment!).
Conventional wisdom has argued that a calorie is a calorie, and it’s all about calories in versus calories out that matters for both weight loss and long-term health. Through time-restricted eating, I have experienced firsthand that not only is a calorie NOT a calorie for meal content but that WHEN you eat those calories influences weight loss and overall health.
While intermittent fasting isn’t appropriate for everyone, many people will experience health benefits from adopting a form of IF. Of course, a lot more research is needed, and intermittent fasting isn’t for everyone. It’s not recommended for people under 18 years of age, women who are pregnant or breastfeeding, and people with some specific diseases. It’s important to check with your doctor to see if it’s safe for you.
If you’ve determined that intermittent fasting is safe for you and you would like some support to implement it into your lifestyle, contact me! I offer a complimentary session over the phone during which we can talk about your goals and how you can be successful in achieving them.