Keto Diet Vs. Intermittent Fasting

In this post, we discuss a common question that gets asked all the time, what are the difference between keto diet & Intermittent Fasting? Both popular diet types are not mutually exclusive of each other and may have some mutual benefits when done at the same time.

However, like any diet, any additional obstacles you add to your routine could end in disaster if you’re not informed. It’s hard enough to do one diet, but doing two is just crazy, or is it?

At we love to use medical studies to prove or disprove a point since there’s just a lot of misinformation on the web. As always, links are at the bottom of all cited sources for this article. Our goal isn’t just to give you recipes, we also aim to educate as much as possible where sources are credible and verifiable.

What is ‘Keto’ Diet?

Let’s first start with what Keto is. Short for ketosis, it’s a state (physiological) of the body where increased presence or production of ketones in your blood are found. Ketones are a source of energy, much like carbohydrates. A hallmark of a keto diet is the restrictive consumption of carbohydrates, typically < 50 grams a day and an increase in caloric intake from fat [1].

Ketone bodies are produced in the liver and are of two types: acetoacetate and β-hydroxybutyrate. As ketone bodies are produced by breakdown of fats, ketosis is the most reliable indicator of fat loss.

Ketogenic diets: Boon or bane?

The presence of elevated ketones in your blood along with a very restrictive carbohydrate intake should induce your body to burn fat for fuel rather than carbohydrates. There are a few ways to achieve a ketogenic state, such as exercise, exogenously, and of course diet.

How fast your body gets into a state of ketosis depends on a number of factors, but in general 4-5 days should show results of ketones in your urine test strip or blood tester. It will take a few more days and up to a week, for your body to fully utilize the ketones being produced, this phase is called ketone adaptation.

What is Intermittent Fasting?

What is Intermittent Fasting
Photo by Djim Loic on Unsplash

Intermittent Fasting (IF) is a popular diet that involves taking periodic breaks from eating. IF takes on different forms, but some of the popular ones include fasting for up to 24 hours once or twice a week, and eating as much or as often as necessary or desired during the remain days of the week.

Another trend of IF is called Time Restricted Fasting (TRF), only eating for a certain amount of time and fasting for the rest in a 24 hour period. You’d basically give yourself an 8-hour window to eat, then fast for 16.

…IF studies result in minimal weight loss and marginal improvements in metabolic biomarkers, though outcomes vary… Additionally, IF has anti-inflammatory effects, promotes autophagy, and benefits the gut microbiome. The benefit-to-harm ratio varies by model, IF protocol, age at initiation, and duration.

Intermittent Fasting: Is the Wait Worth the Weight?

Lastly, Alternate Day Fasting (ADF) is another popular form of IF, where a person will alternate feeding/feasting days with fasting days. There are some limitations within the fasting day such as 0 calorie intake, just water. Then eat as much as you need for the feeding days.

Can You Do Keto & Intermittent Fasting (IF)Together?

Can You Do Keto & Intermittent Fasting
Photo by Sean Stratton on Unsplash

As it turns out, intermittent fasting might be a great combination to kick start your keto diet. I know what you’re thinking, I have to fast & give up carbs? Study shows that fasting can elevate ketones in your bloodstream [2].

However, for ketosis, intermittent fasting (IF) might be the most effective strategy. IF involves “intermittent” but generally prolonged periods of food restriction; such as fasting for a few days each week or month. These more prolonged periods without food are needed to effectively reduce blood glucose, glycogen, and insulin levels throughout the body.

– Health Via Modern Nutrition

Keto Diet & IF are not mutually inclusive of each other. You can be on a keto diet and not be fasting. One of the side effects of being on Keto is the loss of appetite [3]. According to a study, the decrease in food cravings or hunger could be due to the satiety effects of eating protein & fat.

Because of these side effects of being in ketosis, you may actually find yourself intermittently fasting anyway. One rule of thumb that I follow while on keto is to eat only when I’m hungry, in other words, Mindful Eating, not Mindless Eating.

Final Thoughts & Conclusion

I think it’s important to note that keto or intermittent fasting isn’t for everyone. Both can be extremely restrictive depending on your current lifestyle. If you’re used to waking in the morning and having a big bagel breakfast with all the fixings, then sugar in your coffee, then topping it all off with croissant. Keto OR IF will be a huge shock to the system.

I suggest easing into the diet instead of ripping the bandaid off strategy. I find that most people fail their first couple of weeks into a new diet because the change to their daily routine is so drastic that it’s hard to keep up.

It’s best to consult your doctor before starting any diet regimen.

If you’re looking to add Intermittent Fasting to your keto diet, make sure to set smaller goals, what they may be, that’s achievable to get to larger goals in the end. I find that achieving smaller goals helps me stay motivated.

Featured Photo by Uriel Soberanes on Unsplash


  1. Ketogenic diets: Boon or bane? Indian J Med Res. 2018 Sep; 148(3): 251–253.doi: 10.4103/ijmr.IJMR_1666_18
  2. Ketone Bodies and Exercise Performance: The Next Magic Bullet or Merely Hype? Sports Med. 2017 Mar;47(3):383-391. doi: 10.1007/s40279-016-0577-y
  3. Satiating Effect of a Ketogenic Diet and Its Impact on Muscle Improvement and Oxidation State in Multiple Sclerosis Patients. Nutrients. 2019 May; 11(5): 1156.Published online 2019 May 23. doi: 10.3390/nu11051156

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