Intermittent Fasting – Explained

Introduction

Intermittent fasting is extremely popular, but what is it exactly?  In this blog, I review what intermittent fasting is and isn’t and how to get started if you’re new to it as an option for optimal health.

What is intermittent fasting?

Intermittent fasting (IF) is simply an eating pattern that switches between eating and not eating.  It’s not a diet.  It’s scheduling when you eat, not what you eat.  The span of the cycle (eat and not eat) can vary.    

You already “fast” (don’t eat) while you sleep.  This is not a new concept but rather one that has been revived.  Your body is designed to go long periods without eating.  In today’s world, food is available 24/7 and eating has become a love affair of sorts.  Sometimes you eat just to eat!  But that is for another blog.

The most common reason people practice intermittent fasting is to lose weight.  The idea is to reduce your calories, however, if you overeat during the window of consumption, you won’t lose weight.  The same goes for choosing foods that are processed, high-sugar and high-fat.

Why does it matter when you eat?

To understand how intermittent fasting works you need to know the difference between the fed state and fast state in your body.  In the simplest terms…

Fed state

This is when food is digesting and absorbing nutrients.  It starts with your first bite of food and can last for 3-5 hours.  Less fat burning happens during this state because your insulin levels are high.  Meaning, that you have enough fuel from the food you ate and don’t need your fat stores to release anymore.  

Fasting state

After your body is done managing a meal, you’re in the post-absorptive state that lasts 8-12 hours once you last ate and move into the fasting state.  Fat burning can happen now because insulin levels are low.  

The fasting state starts around 12 hours.  Initially, fat is lost, and weight decreases without changing any food preferences.  Eventually, as time goes on and your body becomes more efficient the weight loss will slow and level. 

Methods of Intermittent Fasting (IF)

There are several methods of IF and many variations.  Finding one that is best for you may require some experimenting. Below are the most popular.

Daily IF also known as the 16/8 diet or time-restricted eating (TRE) (Leangains protocol) is very popular.  It’s sixteen hours of fasting and an 8-hour window of eating.  It originated from Martin Berkhan, a fitness expert.  More on “Leangains” IF.

Example: Eat from 8 am until 4 pm (not non-stop); that’s just your window for eating.  You can also wait to eat after you wake up and start at 2 p.m. and stop at 10 p.m.  Whatever works for you!

You already eat around the same time every day so adjusting the clock shouldn’t be too difficult.

Why is 16 hours a magical number? Around the 16-hour mark, a natural metabolic process occurs known as ketosis.  This is when your body burns fat for energy instead of glucose.

Weekly fasting also known as 24 fast (Eat-Stop-Eat) – you can do this once a week or once a month.

Example:  Sunday night is your last meal ending at 7 pm.  The next time you eat is Monday at 7 pm.

I don’t recommend starting with this method as it’ll be difficult to get through 24 hours of not eating.  However, this is a good method to practice once you’re comfortable with fasting consistently.

The 5:2 diet – This diet consists of eating 500-600 calories 2 days out of the week (not back to back) and your normal eating habits on the other 5 days.

I’m not a fan of this method but it might work for you.  I don’t like it because I don’t count calories, I just eat!  If you’re a calorie counter or you track your intake on an app this might be a good option for you.

Tip for blood work: ask your doctor how long you should fast, if required the next time you have lab work done.  I recommend 12 hours even if you’re told 8 hours if you want accurate results.  Don’t eat or drink anything except water.  Don’t chew gum, smoke, or take vitamins.  Ask about medications.  You should stop alcohol for 24 hours as well.

Benefits of IF

Blood sugar control.  Besides weight loss, the major benefit I find most significant is reducing fasting insulin and blood sugar levels.  This practice could decrease your risk of diabetes or improve your glucose if you are a diabetic.  It’s a valuable option for type 2 diabetics if your doctor is educated on the benefits of IF to help you adjust your medications as you begin.

Time saver.  Intermittent fasting will save you time in preparing fewer meals.  The less times you eat the more time you will save in preparing food unless you eat take-out.  Use the time you’re saving to prep healthier meals.

Health tip:  Eating out can pack on the pounds quickly.

Reduce inflammation in the body.  Intermittent fasting helps to reduce oxidative stress.  Oxidative stress can cause damage to your organs resulting in a variety of diseases.

Brain health.  Intermittent fasting can help to increase levels of a brain hormone called brain-derived neurotrophic factor (BDNF).  This hormone is connected to depression and other brain issues.  Intermittent fasting can help stimulate this hormone.

Heart health.  Intermittent fasting can help improve the risk factors for heart disease such as blood pressure, triglycerides, cholesterol, and inflammatory markers.

Health tip: Fasting can reduce various side effects of chemotherapy.

How to start IF

Ease into it.  Start by not snacking in between meals.  Then move on to not eating after dinner.

Next, pay attention to when you last ate or drank anything with calories.  Extend your fast when you wake up to meet a total of 12 hours.  After 12 hours, eat a regular meal.  Don’t eat again until 4-5 hours have passed.  No snacking on food or drinks with calories.  Nothing!

Once you’re used to not eating for 12 hours, bump it up to 14 hours.  The goal is 16 hours but allow yourself some time to reach this magical number.

When starting, don’t focus on what you’re eating but when you eat.  Over time, you can improve your food choices to benefit from the maximum method of IF.

Experiment with any of the methods listed above to find your optimal approach.

Conclusion

Start with a reasonable window of time like not eating for 12 hours.  Less than 12 hours is not effective.

For healthy individuals: you won’t die if you don’t eat for 12-16 hours or even 24 hours but will need to experiment with which method works best for your lifestyle.

Not recommended for anyone with an eating disorder, underweight, or underlying health conditions. 

Check with your doctor if you’re taking medications before you start intermittent fasting. Limit your processed foods and focus on healthier choices once you get used to the best method for you!

In optimal health,

Lisa