A recent study found that over the course of a year people can lose about 5% of their body weight by staying consistent with intermittent fasting. This article is a guide to the most popular form of fasting, 18/6.
During prehistoric times, before humans understood planting crops and farming, they would hunt and gather their food. Johns Hopkin's, Mark Mattson, is a neuroscientist who has studied intermittent fasting for over 25 years, says our bodies evolved and the benefits of going without food can still be seen today.
He calls it the metabolic switch, after hours without food your body runs through it stores of sugar and begins burning fat. This process is called ketosis.
What our ancestors called a "bad hunt" we now happily participate in and call it "intermittent fasting."
Intermittent fasting is where you have a set window during the day when you can eat. The rest of the day, you abstain from eating, keeping your body in a fasting state.
18/6 intermittent fasting is when you abstain from eating for 18 hours and eat all your meals in a 6-hour window.
You should choose your time restricted eating window based on your lifestyle and what works best for you. You could skip breakfast, start your first meal at 12:30 pm and end your time restricted eating window at 6:30 pm to eat dinner. Others may choose to start their first meal later in the day to have a later dinner. You may have to try out different schedules to see what works best for your lifestyle.
How does IF work? I think Gin Stephens in her New York Times best selling book "Fast. Feast. Repeat." said it best:
"Insulin is the key to whether your body is in fat-storing mode or fat-burning mode, and fasting puts you solidly into the fat-burning side of the equation … which is just what we want!"
18:6 is known as one of the more difficult IF schedules. Keeping your body in a fasting state for 18 hours isn't something you jump right into. If you have tried 12:12 or 16:8 and didn't see results, or if you want to kick your weight loss up a notch, 18:6 might be for you.
Some people do alternate day fasting periods, which are a bit easier and potentially a starting point if you are interested in trying 18:6. Alternate-day fasting typically involves fasting every other day and restricting your calories to 25% of your energy requirements. For example:
Day 1: Eat normally
Day 2: 25% (500 calories)
Day 3: Eat Normally
As for the success of ADF, some studies have shown a potential weight loss between 3-8% within 12 weeks.
18 hours without food can be challenging, but many people experience better digestion with the 6-hour eating window. With a goal of 18 hours, you may notice reduced bloating and indigestion that occurs when you eat too frequently.
Of course, the number one benefit of IF for most people is weight loss. Here are some added benefits to 18:6 IF:
One of the primary benefits of 18:6 intermittent fasting is weight loss. Your body goes into ketosis as your blood levels of insulin drop.
Also, by limiting your calorie intake and the time frame in which you consume your calories, you may be able to create a calorie deficit without feeling deprived or hungry. Studies have shown that intermittent fasting can help you lose weight and reduce body fat, while maintaining muscle mass, leading to more muscle growth a healthier overall body composition.
How much weight loss depends on a lot of factors, it especially helps you lose weight if you combine fasting with a healthy, balanced diet and an exercise plan. One study found a 3-8% weight loss over 3-24 weeks, and another found a reduction in waist circumference of 4-7% between 6-24 weeks.
Inflammation is the root cause of many chronic diseases, including heart disease, arthritis, and even cancer. By reducing inflammation in the body, 18/6 intermittent fasting can help lower the risk of developing these diseases. Studies have found that intermittent fasting can reduce inflammation markers in the body, leading to improved overall health.
By limiting the time frame in which you consume your calories, your body is better able to regulate blood sugar levels. This balance helps reduce the risk of diseases later in life.
Many people who practice intermittent fasting report feeling more energized during the day. Fasting triggers a natural release of adrenaline and other hormones, leading to increased alertness and focus. Additionally, fasting can help regulate sleep-wake cycles, leading to better sleep quality and increased energy levels during the day.
Speaking of sleep, 6-hour eating window may also improve your sleep. Most people doing 18:6 end their meals between 6:30 - 7:30 pm, rather than eating right before sleeping. The structure of consciously timing your meals and not eating late helps regulate your sleep cycles, leading to better sleep quality and more restful nights.
Numerous research studies on both animals and humans have shown a handful of benefits to practicing intermittent fasting (IF). Studies have shown intermittent fasting to be effective at supporting healthy blood pressure and resting heart rate. As for weight loss, IF can effectively help lose around 0.8% to 13.0% of your body weight in multiple studies ranging from 2 weeks up to a full year.
However, a recent study at John's Hopkins showed IF wasn't associated with weight loss, but the age old "fewer and smaller meals" is the more effective weight loss strategy.
You will likely be starving when it's finally time to start your eating window, but make sure you plan ahead for how you are going to break your fast. You can read the read the complete guide here, but to summarize:
Ease your system back into gear with something under 500 calories and easily digestible.
Drink water during and after you break your fast. There are countless benefits to being hydrated.
The rapid spike in blood glucose will definitely end up making you tired.
Short term diets are not a long term solution, but the nutrition & lifestyle choices made while 18:6 IF could be beneficial if added to your consistent routine. Once your body adjusts, it should become easier. It takes 66 days to make a habit automatic, but you can do this!
How often you fast is completely up to your personal preference and depending on your health conditions as well as what goals you are looking to achieve.
If you have concerns you should consult your doctor before making any dietary changes. A fast should always be planned ahead including timing, hydration, and breaking the fast. Pay very close attention to how your body feels and what it is signaling.
18:6 intermittent fasting is when the fasting period is 18hrs and consists of absconding from food. You should choose whichever window suits you the most. You might start with 1:30pm and then finish with the dinner at 7:30pm.
You can drink liquids that don't contain calories like water, herbal tea, or black coffee.
Anything over 50 calories would be considered breaking the fast and disrupting the metabolic state otherwise achieved through fasting.
The older I get the less inclined I am to lean into what's trending on the internet. But needless to say, there may be an opportunity cost to not embracing the future, or even remaining on the sidelines so long that you have to catch up.
The mission of The Driven is to help equip you with the tools to live smarter, better lives. Today, I want to challenge you to lean into learning the basics of artificial intelligence-powered chatbots, specifically, Chat GPT. Launched in November of 2022, Chat GPT was the leader of AI chatbot tools and is truly a groundbreaking tool that is changing the way we communicate and create.
Comments will be approved before showing up.