Intermittent Fasting 101: Everything You Wanted to Know
Intermittent Fasting (IF) has received a lot of hype recently, however; Intermittent Fasting actually isn’t a new concept. It has been practised for thousands of years, mostly for religious reasons. I hear you right now: before you can convince me to do anything with the word 'fasting' in it, you're going to have to make a good case for it.
I agree: the word ‘fasting’ sounds pretty... miserable.
What we don’t realize is that you actually ‘fast’ every single day - we just call it sleeping. From the time you eat your last snack or meal of the day until you munch breakfast the next morning, you are in a ‘fasted’ state.
What’s the deal with IF, are there any benefits and I love breakfast, do I have to give up?
What is Intermittent Fasting?
Intermittent Fasting differs from other diets as it focuses on controlling meal timing rather than the what you’re actually eating. The idea behind Intermittent Fasting is that you are consciously ‘skipping’ meals to put your body into a Fasted State.
Quick Biochemistry Lesson
From the second your food hits your mouth until it goes through your small intestine, it is being broken down into glucose. Glucose is taken up by the cells and turned into ATP, which the body uses for energy. This is called the Fed State- using available glucose from food as the main fuel source. In this state, our bodies rely on the hormone insulin to signal that there is sugar (glucose) available. This is important because when there is an excess of glucose (due to too much food, lots of sugar, or simple carbohydrates) excess insulin is excreted. Extra glucose is also converted into fat as a form of energy storage (hello, muffin top). This insulin signal can become dysregulated and our bodies can become less sensitive to its signal. This causes the glucose level to stay high in the bloodstream and low in the cells so our bodies believe that they are starving, even when there is enough glucose available. This dysregulation can lead to Diabetes, Polycystic Ovarian Syndrome and other metabolic conditions.
Between meals, there is no food available and this puts you in a Fasted State. In this state, your body relies on stored fat for fuel. The fat stored in the liver and adipose tissue are turned into compounds called ketones which are turned into ATP. It takes around 4 hours post-meal for your body get into this state.Both the Fed State and Fasted State have the same goal: make ATP for the body to use as energy. The difference lies in the starting source: glucose (from food) vs. ketones (from stored fat).
I'm not telling you about skipping meals just for fun, the good news is there are benefits to this madness...
The Benefits of Intermittent Fasting
Studies have shown that IF can:
Promote weight loss, especially in the belly area
Regulate insulin levels
Improve appetite control
Improve heart health by decreasing cholesterol, blood sugar and triglyceride levels
Decrease inflammation
Improve leptin (satiety hormone) control
Improve HbA1c (blood sugar marker)
Increase Human Growth Hormone aka HGH (which can help increase muscle mass and increase fat burn)
The 2 Main Methods of Intermittent Fasting:
The 16/8 Method
This is usually the easiest method for people.
Fast for 14-16 hours and feed for 8-10 hours.
Example: For a 16 hour fast: eat between 10am and 6pm and fast between 6pm and 10am the next morning.
Fasting for 14 hours is usually enough to notice the benefits of IF.
The 5/2 Method
This method focuses on 5 days of regular eating and 2 days of restricted eating per week.
On the 2 days of restricted eating, eat 20-25% of total normal calories for the day.
For example: If you normally eat 2000 calories per day, on the fasted days you eat 400-500 calories for the day.
The 2 days should be separated by at least 1 day of regular eating between.
For example: fast on Tuesday and Thursday, eat normal the rest of the week.
Who May Benefit from Intermittent Fasting?
Adults who:
Want to lose weight or are having trouble losing those last few lbs
Want to naturally increase Human Growth Hormone to increase muscle mass
Feel as though they are always eating, hungry or have lost the ability to feel full
Are Prediabetic or Diabetic
Have Polycystic Ovarian Syndrome
Have high cholesterol
Want more freedom from food. Having to worry less about food can free up mental energy for meal prep and leave more time for things you need to do.
Keynote for women and/or those with a history of disordered eating:There are some evidence that women should be careful with Intermittent Fasting. This is because of some reports that IF can cause hormonal dysregulation and affect menstrual cycles. It is important for women to only implement fasting on alternate days or for a maximum of 3 days per week. Women who are looking to conceive, have fertility issues or have pre existing hormonal concerns must be extra careful. Also, if you have a history or disordered eating, this may not be the best method for you as it can be triggering. ALWAYS CONSULT AN ND OR MD BEFORE IMPLEMENTING INTERMITTENT FASTING.
Top FAQS:
Can I eat or drink anything during the fasting time?
During the fasting window you should not eat.
You can drink water, bone broth, tea (black, green, matcha or herbal - black without any additions including milk or sugar) and black coffee.
Do I have to give up breakfast?
You definitely don't have to give up 'breakfast' or any other specific meal. You can adjust your feeding window so that it includes the meal you need it to. Ex for the 16/8 method, if you stop eating at 5pm, you can eat breakfast the next day at 9am.
Will I lose muscle mass?
The first thing we worry about when we decrease caloric intake is that we will lose muscle mass. Studies have shown the IF, while decreasing body fat, does not change body composition. This means that there is no net change in muscle mass compared to any caloric restricted diet.
Be sure to make sure you’re meeting your protein needs to further prevent muscle loss.
Can I work out while fasting?
Yes you can. As long as you normally workout and feel okay to. Be sure to tune into how you feel and don’t push your limits too far.
Important Notes/Tips
Make sure you are getting enough of your macronutrients: FAT AND PROTEIN
When doing any type of caloric restriction it is important to make sure you’re getting enough protein and healthy fat to sustain your muscle and energy needs and provide a source of fats to produce hormones.
Studies comparing high fat IF diet to low fat IF diet showed that the high fat diet actually lost more weight than the low fat diet.
Do not compensate for calories on your regular eating days
Try not to compensate for the calories you did not eat on the fasting days or during the fasting window - this will set you back!
Eat normal sized meals as you would on a regular day.
Start SLOW
Do not start with any of these methods right away. Slowly ease in by starting with a 12 hour fast, 1 day per week and working your way up.
For some people 1 day of IF per week may be enough.
I cannot stress enough: do not just start IF 'for fun' OR if you are under 18.
IF is beneficial for some of the conditions and health goals mentioned in this article. Starting IF just to try and doing it incorrectly or without being monitored may actually be detrimental to your health.
This is especially true if you have a history of disordered eating or harmful eating patterns.
Overall, intermittent fasting can be a simple way to make a positive change to your health, weight and fitness. My personal favourite benefit: 1 less meal to to worry about prepping.
If you are interested in Intermittent Fasting or think it would benefit you and help you reach your health goals, I am a Naturopathic Doctor virtually, and in person in Toronto and Vaughan and would love to help you reach your health goals.
In health,
Dr. Courtney Ranieri, ND
The information presented in this article should only be used for informational purposes. This article should not be used to diagnose or treat any medical concerns. The information presented should only be implemented after consulting with your Naturopathic or Primary Doctor and after a thorough medical assessment.
References
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