Intermittent fasting (aka time-restricted eating) has a bunch of cool health benefits. Some of them are more obvious than others.
Today I’ll cover 9 significant benefits of intermittent fasting that I suspect you would want to know about. Each of these benefits is related to common health problems (including some of the biggest killers out there).
For the most part, I’ll be using simple logic and physiology to demonstrate what I’m talking about. But I’ll include a few scientific references as well.
I think the more you understand about the health benefits of fasting, the more motivated you’ll be to put it in practice. So it’s a useful thing to learn about!
Let’s dive in.
If you prefer, I also have a video where I explained each of these benefits.
1. Intermittent fasting Smooths Out Your Blood Sugar
The logic here is simple:
When you eat, your blood sugar tends to go up. So if you eat less frequently, your blood sugar doesn’t go up as often.
In other words, you don’t get those “spikes” of blood sugar or insulin as frequently throughout the day.
The fewer spikes you have in your blood sugar in your insulin, the lower your overall blood sugar and insulin levels will likely be.
That’s definitely a good thing if you have pre-diabetes or diabetes (or you’re trying to avoid having them)!
2. Intermittent Fasting Reduces Insulin Resistance
Insulin resistance or high insulin levels is at the root of most chronic illnesses.
That includes type 2 diabetes, high blood pressure, polycystic ovary syndrome, dementia, and various others. It’s even related to some types of cancer.
What is insulin resistance?
Basically, it just means insulin doesn’t work as well in your body, so your pancreas has to keep pumping out more and more of it to get the job done.
The end result is excessively high insulin levels, which has a bunch of undesirable downstream effects.
Fasting helps normalize insulin levels, because you don’t have as many blood sugar and insulin spikes throughout the day.
Fasting also gives your internal organs (like your pancreas and liver) a break, so they can do some resting and renewing. That further improves the insulin “sensitivity” of these key metabolic organs.
Overall, normalizing insulin levels is a big way that intermittent fasting can indirectly reduce your risk of a host of different health conditions, including diabetes and heart disease (see below).
3. Intermittent Fasting Lowers Your Risk of Heart Disease and other Chronic Illnesses
On a related note, if you have diabetes you’re at a much higher risk of getting heart disease, including heart attacks. So anything you can do to prevent or reverse diabetes will dramatically lower your risk of heart problems.
Fasting is an effective way to improve or prevent type 2 diabetes. So using simple logic, it’s also clear that fasting can lower your risk of heart disease.
Type 2 diabetes also raises your risk of various other health problems, like blindness, kidney failure, strokes, and many more. So anything that can prevent diabetes will also make you a lot more likely to stay healthy in the long run.
Another way that fasting lowers your risk of heart disease is by lowering your triglyceride levels. Triglycerides are one of the molecules measured on your cholesterol panel, and having high triglycerides is a significant risk factor for heart disease.
4. Intermittent Fasting Improves Blood Pressure
In case you haven’t noticed, high blood pressure is super common. It seems like almost all my patients in the emergency room have it.
One very common cause of high blood pressure is insulin resistance. That’s because elevated insulin levels cause various changes that contribute to high blood pressure.
One important mechanism is that high insulin causes your kidneys to retain more salt and water. If you have more salt in water in your bloodstream… there’s more pressure as well. Hence high blood pressure.
Fasting is a quick and effective way to help normalize your insulin levels, which can in turn improve blood pressure.
5. Time-Restricted Eating can Improve Your Sleep Quality
Here’s something interesting you might not know:
In addition to the circadian rhythm linked to light-dark cycles, your body also has a second circadian rhythm linked to food timing.
The light-dark rhythm is regulated by your brain. The food rhythm is regulated by your liver.
Why does this matter?
Basically it means that one way you can improve your sleep quality is by focusing on the timing of when you eat.
If you finish eating at least a few hours before bedtime, and give your body plenty of time to digest your food before sleep, you’re likely to have more restful and regenerative sleep.
In contrast, if you eat a lot of food close to bedtime, your sleep won’t be as restful because your body still has to focus a lot of its energy and attention on digestion.
(For more information on this topic, try reading The Circadian Code by Dr. Satchin Panda, PhD.)
6. Intermittent Fasting Improves Brain Health
Dementia (like Alzheimer’s) is sometimes called type 3 diabetes nowadays.
That’s because one important mechanism of developing dementia is when your brain has insulin resistance, and can’t use blood sugar (glucose) as effectively.
Fasting helps reverse insulin resistance, which can in turn reduce your risk of developing a condition like dementia.
Related Post: KetoFlex 12-3 [Fasting + Ketosis for Alzheimer’s]
Fasting also helps boost ketone levels (similar to a ketogenic diet), and ketones are an alternative energy source for the brain. If you have ketones around, your brain won’t have to rely on glucose, which means it can likely function better in unfavorable conditions like dementia, or after a brain injury.
Fasting also increases your levels of something called BDNF (Brain-Derived Neurotrophic Factor), which tends to be low in conditions like depression. When you boost BDNF, it stimulates brain growth and healing.
Those are just a couple of the ways that fasting can potentially improve your brain health.
7. Intermittent Fasting Makes it Easier to Manage Your Weight
When you eat, your body spends a few hours storing energy, including body fat. When you don’t eat (i.e. fasting), you get into fat burning mode, and use up some of the excess energy you previously stored.
Here’s the bottom line:
By spending some time fasting, you’ll spend more time in fat burning mode, which makes it easier to manage your weight.
One reason this works is because when you’re fasting your insulin level stays nice and low. Low insulin allows your body to access body fat for energy.
Personally, I’ve found it significantly easier to manage my weight when I do time-restricted eating on a daily basis. It also seems to help a lot when I do an occasional 24-hour or 36-hour fast.
Even if I overeat on special occasions, doing a bit of fasting seems to help balance this out quite effectively, keeping me around the same weight without a lot of extra effort.
8. Intermittent Fasting Reduces Hunger
This benefit is kind of counterintuitive. Most people would think that when you stop eating you would get hungrier and hungrier until you start eating again.
Turns out, not so.
Fasting actually reduces levels of the hunger hormone called and ghrelin. Fasting can also retrain your body and your mind, so that you don’t feel like you have to eat as often.
In other words, you can gradually shift into a new schedule, kind of like a new circadian rhythm, in which meals are less frequent–and your body is fine with that.
Ultimately as you get more practice with fasting, it gets easier not to eat as often, and you don’t feel hungry as frequently as you did before.
9. Intermittent Fasting is Convenient!
This is the only benefit on the list that’s not related to health. But another big advantage I’ve found from intermittent fasting is the convenience.
On days when I’m fasting, I have bigger blocks of time where I can focus on doing work, or just enjoying hobbies, time with friends, etc.
When you think about it, it’s pretty obvious. Less time eating = more time for other things.
It’s especially true when I do a longer fast, in which case I might not eat it for most of the day.
It’s also a big reason why I do a lot of fasting at work–the extra time I get by not worrying about food makes it easier to keep up with all the demands in a busy emergency room.
(Staying busy and distracted at work also makes it easier to fast, so it’s beneficial from multiple angles.)
In recent years it’s become abundantly clear that intermittent fasting (aka time-restricted eating) has a bunch of health benefits. This includes lowering your risk of various health conditions, including diabetes, heart disease, and many more.
It also makes it easier to manage your weight, even if you indulge from time to time on special occasions.
In addition to all the health benefits, there are also other practical benefits like the convenience of not having to do as much food prep, or worry about food as often.
I think the more you understand about the health benefits of fasting, the more motivated you’ll be to put it in practice.
Thinking about the positive health changes you’ll experience from fasting is also a good way to get in the right mindset before or during a fast.
Hope it helps!