Possibly the two hottest diet plans around right now are the keto diet and intermittent fasting. Both claim to provide a wide array of health benefits well beyond weight loss. But can you follow both plans at the same time?
Yes! Not only are these two diets compatible, but they might even enhance one another. Have you hit a plateau with your keto diet? Or maybe you’re looking for a way to make intermittent fasting more manageable and effective? Well, you might want to consider taking advantage of this powerful duo.
First, let’s get a quick refresher on what exactly these two diets are.
What is Intermittent Fasting?
Intermittent fasting is a schedule where you only eat during a set window of time, say 8 hours. Then you don’t consume any calories for the rest of the day. So unlike most diets which are all about WHAT you eat, this plan is only concerned with WHEN you eat.
By limiting your eating time, intermittent fasting kicks your body into fat-burning mode. (1) Not only does this stimulate weight loss, but it also catalyzes a whole host of additional metabolic benefits, ranging from mental focus and increased energy to better cardiac health.
What is a Ketogenic Diet?
The ketogenic (or “keto”) diet is essentially a low-carb and high-fat eating plan. Specifically, it prescribes eating 70-80% of your calories from fat sources, 15-25% of your calories from protein, and limiting your carbohydrate calories to 5% of your diet. The average Keto dieter tries to eat less than 40 grams of carbohydrates per day.
Eating in accordance with a keto diet is intended to shift your body to burning ketones for energy, instead of glucose (sugar and other carbs).
Here’s how it works: when you dramatically limit your carbohydrates, your body eventually goes into “ketosis,” which means it’s using ketones for energy. Translation: your body is using fat stores for energy.
Using fat as a fuel source is actually believed to be less stressful for your body and to give you more energy. Also, giving your body a break from having to work to regulate your blood sugar levels leads to lots of health benefits.
Interestingly, a keto diet actually mimics the effects of fasting, without the fasting. In other words, eating very little carbs can have the same effect on your body as eating nothing at all.
What to Eat on a Keto Diet:
|Protein (15-25%)||Fruit/Veggies (5%)||
How Intermittent Fasting Boosts the Benefits of the Keto Diet
Ok, so we’ve got the basics of each of these diets down. How exactly do they benefit one another
1. Shift into ketosis sooner
One of the primary goals of a keto diet is to get into ketosis as quickly as possible and to stay there for as long as you can. When you practice intermittent fasting, your fasted state has already starved your body of carbs, which means your glucose levels are lower than those of someone who doesn’t fast.
This means that when you’ve been fasting, your body will shift to burning fat reserves and ketones even sooner. And that translates to getting you into ketosis much more quickly than if you weren’t fasting.
The flip-side of this is also true. Being in ketosis mimics fasting because your body is burning fat for fuel. So if you’ve been trying an intermittent fasting plan but haven’t really noticed any results, following a keto diet during your eating windows might just give you the jumpstart you’ve been looking for.
2. Lose weight faster
The common core that intermittent fasting and the keto diet share is that they are designed to switch your body from burning glucose to burning fat instead. And when you put both diets together, your fat burning is actually maximized.
Here’s why: if your keto diet has successfully put you into ketosis, then your body has adapted itself to using fat as fuel. When you add intermittent fasting into the mix, your body has a head start on the fat-burning track and will actually be even more efficient at continuing to burn fat.
Compare this to someone who doesn’t follow a keto diet. When they adopt intermittent fasting, their body will be much slower to enter the fasted state, which is where all the fat-burning magic happens.
3. Boost your brain health and mental focus
Did you know that your brain is one of the body’s biggest consumers of energy? It’s true. And it just so happens that fat, not glucose, is the most energy-efficient fuel that your body can run on. Since both intermittent fasting and the keto diet train your body to burn fat for energy, your brain reaps huge benefits from both these plans.
After all, we always have fat stores available to burn. So as long as your body knows how to tap into those fat stores for fuel, your brain has a constant energy source on which to run. This is why people following both intermittent fasting and the keto diet experience more mental clarity, focus, and other neurological benefits. (2)
There’s even more good news for your brain. Studies have shown that fasting boosts production of a protein (BDNF) that feeds your brain stem cells and promotes neural health. (3)
4. Make both diets easier
Let’s be honest, one of the main reasons some of us are skeptical about trying intermittent fasting is that fasting leaves you feeling hungry. A keto diet, however, is known to help decrease cravings and hunger, due to the high-fat content of the keto eating plan (4).
So if you’re already following a keto diet, you may find the fasting windows of an intermittent fasting plan much easier to manage. Both eating plans are designed to keep your insulin levels steady, which means less cravings and hunger pangs over the long term.
5. Enhance your exercise
Can you even exercise while you’re fasting? This is a common concern, but the answer is a resounding “yes!” Not only is it okay, but a growing number of studies show that following intermittent fasting and a keto diet can in fact enhance the long-term health benefits of your exercise program.
Both intermittent fasting and the keto diet train your body to burn stored fat for energy. This triggers a variety of metabolic adaptations that will actually increase your workout performance while you’re fasting. (5)
Worried about losing muscle? Don’t be! This study revealed that you can actually maximize your muscle gains when you train while fasting. And this study indicates that when you do strength training in a fasted state, the nutrients you consume afterwards will be better utilized by your body than if you hadn’t been fasting during your workout. Pretty cool!
And for those of you concerned about whether your actual workout performance will suffer as a result of fasting, not to worry. Studies have been done on Muslim athletes who fast for Ramadan, and no negative effect on performance was found. If you do decide to workout while fasting, we recommend you do it right before you start your eating window for the day.
Other Benefits of Intermittent Fasting
Want to know more? You can read more details about the potent long-term health benefits of intermittent fasting here.
Tips for Starting and Sticking With It
1. Listen to your body
As with any new diet plan or exercise regimen, only you yourself can be the ultimate expert. We are all unique and will respond differently to the same plans.
If you’ve decided to follow a 16:8 intermittent fasting schedule but find yourself really struggling, tired and hungry, don’t hesitate to modify your schedule. Try shifting your eating window to later in the day, or check to make sure you’re getting enough high-quality keto food calories.
If it’s still not working for you, maybe try expanding your eating window to 10 hours, or only practice an intermittent fast every other day.
2. Don’t start both at the same time
So you’re really motivated to take advantage of the potent fat-burning effects that these two diets offer. We get it! But if you’re brand new to both intermittent fasting and the keto diet, it’s not recommended that you try to adopt both at the same time. Trying to master the new eating habits of a keto diet while also sticking to the new schedule of intermittent fasting can be overwhelming, to say the least, which means you’ll be more likely to give up.
We recommend starting with an intermittent fasting schedule for approximately two weeks, so that your body has time to adjust to the new pattern. At this point, your body will also be more adept at shifting into a fat-burning zone, so that when you start eating a keto diet, you’ll likely find it easier to drop into ketosis.
3. Drink tea
Even during your fasting windows, you are allowed to consume as many calorie-free beverages as you’d like. Die-hard keto followers, take note: bulletproof coffee counts as breaking your fast. So if you’re following an intermittent fasting schedule that has you fasting between 8pm and noon, you shouldn’t drink your bulletproof coffee before noon.
The best alternative? We highly recommend tea, as it will not only keep you hydrated, but it also promotes gut health, wards of cravings and assists your body in detoxification.
How the Keto Diet and Intermittent Fasting Can Boost Sports Performance
One of the more surprising aspects of both the Keto diet and intermittent fasting is that some seriously tough athletes claim these eating plans help to increase their athletic performance.
They just might be on to something. If you’re looking to boost your sports performance, here’s what you should know: one of the primary reasons these eating plans work is because training your body to burn fat can help you recover from exercise more quickly. And if you eat a keto diet and follow an intermittent fasting schedule, then your body becomes increasingly more efficient at switching over to fat-burning mode. The easier it is for your body to burn fat, the better your athletic performance and recovery time.
There’s a growing number of endurance and elite athletes who have incorporated fasted training into their programs. Fasting creates a combination of high adrenaline and low insulin levels that further stimulates burning fat for energy. And if you’re looking to add lean muscle mass, regular fasting has been shown to increase growth hormone levels, which helps with muscular development.