intermittent fating without keto

Intermittent Fasting Without Keto: Why It Works

Many people turn to intermittent fasting and the keto diet for weight loss. Why? Because these two methods are much more sustainable than calorie restriction long term, but can you benefit from intermittent fasting without eating keto or do you need to do both to achieve the best results? Find out in today’s blog post.

Intermittent Fasting Without Keto for Weight Loss

First, it’s important to understand how the keto diet and intermittent fasting work for weight loss.

How Does the Keto Diet Work?

The keto diet is a very low carb, high fat, and moderate protein diet. Of your total macronutrient intake, 5% will be carbs, 20% protein, and 75% fat.

If you wonder what 20 g of carbs look like, let me give you some examples:

  • 3 pounds of spinach
  • 400 grams of raspberries or blackberries
  • 150 grams of blueberries
  • 1 1/2 cups of pecans
  • a plate of spinach, zucchini, tomatoes, and peppers
Image Credit: Diet Doctor

On the keto diet, your are consuming so little carbs that your body runs out of glycogen and starts using stored fat to produce ketones for fuel. When your body uses ketones for energy, you are in ketosis.

How Ketosis Helps You Lose Weight

When you are in ketosis, your appetite decreases and your body burns fat. Naturally, you eat less. Moreover, ketone production decreases inflammation in your body, which also helps lose stubborn weight. Conversely, continuous calorie restriction makes you feel hungrier and hungrier and that’s really hard to sustain long term.

For a Step-by-Step Success Formula to Lose Weight, Kick the Cravings, and Tone Your Body in Just 30 Days, check out my 30-Day Intermittent Fasting Transformation.

Intermittent Fasting and Ketosis

Your body runs out of glycogen and starts using fat for fuel on the keto diet, but this also happens when you are practicing intermittent fasting (learn How to Start Intermittent Fasting in 5 Simple Steps). After a 12 hour fast, your glycogen reserves are getting low. Exactly how long it will take your body to release ketones depends on many factors, including whether you have been in ketosis before or not.

With experience, you will be able to feel when you are in ketosis. For me, it takes around 18 hours each day. You will need to experiment to find out how long YOU need to fast (keep reading, I will show you how).

Intermittent Fasting Vs. Keto

In a way, the ketogenic diet mimics fasting by helping your body run out of glycogen without avoiding food. For those getting started, doing the keto diet is a great way to kickstart ketosis fast. Intermittent fasting will be a lot easier once you have been in ketosis.

Why Intermittent Fasting Without Keto May Be Best for You

However, you should be aware that prolonged fasting (and in some cases even intermittent fasting as you will see below) combined with the keto diet could put you at risk for ketoacidosis if you have diabetes.

The Keto Diet and Ketoacidocis

Ketoacidosis is a serious condition that is usually associated with diabetes, but not always. It causes dehydration, poor appetite and difficulty breathing. I found this case where a lactating woman on the ketogenic diet suffered from ketoacidosis particularly revealing. Women in general, but particularly lactating women need more carbs for proper hormonal function.

I am not claiming the keto diet is dangerous and should not be practiced. What I am saying is that if you are doing both intermittent fasting and the ketogenic diet, proceed with caution.

Carbs and Hormone Function

Low carb and ketogenic diets have been shown to help with weight loss and metabolic health. However, carbs support hormone function and the stress caused by the lack of glycogen may cause hormonal disruptions. Women may even experience amenorrhea. This type of amenorrhea is called functional hypothalamic amenorrhea . It is most commonly caused by too few calories, too few carbs, weight loss, stress or too much exercise.


Leptin is another hormone that may be affected by a diet too low in calories or carbs. Leptin is produced by your fat cells and it helps you feel full. Moreover, it contributes to regulating women’s reproductive hormones. Low carb diets reduce leptin production (but improve leptin sensitivity).


Fasting and a keto diet increase cortisol levels. Cortisol has many benefits, including reduced inflammation and fat loss. However, too much of a good thing can become a bad thing. Too much cortisol can have the opposite effect and cause fat storage and lower estrogen production.

Thyroid Function

T3, the active thyroid hormone is sensitive to calorie and carb consumption.

Fasting and Hormone Function

The studies that show a connection between poor hormonal health and low-carb or ketogenic diets also relate to calorie restriction. Too few calories (or fasting) could have the same effect. Read How Intermittent Fasting Affects Women’s Hormones for more info.

How to Include Carbs in Your Diet

Now, if you decided to follow a diet that includes more carbs than the keto diet, you might want to try a moderate amount of carbs (between 100 g-150 g). Most women will thrive within that range. Some do very well on a high carb diet (anything above 225 g), but many will find that they feel hungrier when consuming too many carbs.

Here are good examples of carbs that will support your health:

  • All veggies and fruits
  • Legumes
  • Nuts and seeds
  • Whole grains (in moderation)
  • Tubers (potatoes, Jerusalem artichokes, jicama, and yams)

Why Intermittent Fasting Without Keto Works

As I mentioned already, what separates a keto diet and intermittent fasting from calorie restriction for weight loss is the fact that your body is producing ketones. Using ketones for fuel as many benefits beyond weight loss. Here are some benefits you will achieve when practicing intermittent fasting even if you don’t follow a keto diet:

  • Better mental focus
  • More energy
  • Better mood
  • Less appetite
  • Better sleep

As you become more experienced with intermittent fasting, you will be able to notice these changes. Intermittent fasting without the keto diet works because your body runs out of glycogen when you fast and starts producing ketones.

Intermittent Fasting Vs. Low Calorie Diet

Low-calorie diets help achieve similar benefits (not from ketone production, but from lower insulin levels). They will even allow your body to repair itself through autophagy. However, the problem with low-calorie diets is that they are are the sustain long-term. Reducing your calorie intake by 20% is enough to make you feel deprived and hungry.

I do recommend short term calorie deprivation to mimic the effect of prolonged fasting. This type of calorie deprivation is more severe as it allows you to consume only 40-50 % of your normal calorie intake. It’s called the fasting mimicking diet and it has many health benefits. It is also how I was able to achieve ketosis without the keto diet (read my Fasting Mimicking Diet Results).

Can You Lose Weight Without a Calorie Deficit?

When people talk about intermittent fasting, they often mention that you don’t have to count calories. That’s true! However, that’s not to say that you don’t need a calorie deficit to lose weight. What most likely happens is that intermittent fasting creates a calorie deficit naturally as your appetite decreases. It may also be that you are decreasing inflammation, which also helps losing weight. If you want to lose weight using intermittent fasting, read Top 5 Reasons Why You Are Not Losing Weight Using Intermittent Fasting.

Can You Do Keto Part-Time?

You may wonder if it would be worthwhile to do keto part-time. My answer is: of course! Doing the keto diet part-time would be a great way to get into ketosis faster and make intermittent fasting easier.

Intermittent Fasting Without Keto Schedule

Alright, so you are convinced you want to do intermittent fasting without the keto diet. Now what?

Ketosis With Intermittent Fasting Step-by-Step

You will need to think of the right schedule for your lifestyle and experiment to see what works best for you.

Kickstart Ketosis

If you are just getting started with intermittent fasting, I suggest you start with the fasting mimicking diet or the keto diet. If you choose the keto diet, you may only need a few days as well. You will most likely get the keto flu and when you feel better, you will be in ketosis.

If you choose the fasting mimicking diet, you may not notice a difference the first time around. Keep experimenting with intermittent fating the rest of the month and you will notice that when you do the fasting mimicking diet again (after a month), it will be a lot easier. You will achieve ketosis.

Choose Your Intermittent Fasting Schedule

For some people, it takes more than 16 hours to get in ketosis using intermittent fasting. Testing could be helpful. I use this ketone monitor (this is an affiliate link that will give you 15% off your purchase):

You are in ketosis when your reading is anything above 0.5 mmol/L. With time, you will know the difference without even measuring.

Start gradually, fast from 8 pm to noon the next day for 2-3 weeks, and see if you notice a difference. If you don’t, increase your fasting window (8 pm to 4 pm the next day works best for me) or try a different intermittent fasting method that doesn’t require daily fasting like the Eat-Stop-Eat Diet.

My Fasting Without Keto Success Story

My story started years ago when I started experimenting with intermittent fasting and other weight loss plans. The first intermittent fasting method I tried was the 16:8 method. In fact, I didn’t realize there were other methods! When I didn’t see the results I was hoping for, I gave up.

Then, I discovered the fasting mimicking diet. The fasting mimicking diet intrigued me mostly for its health and longevity benefits (read 5 Steps to Fasting for Health and Longevity if that’s something that interests you as well).

However, I was excited to discover that even though I regained the few pounds I had lost at first, the weight started melting off during the rest of the month. I also lost the belly fat and it did not come back even though I was eating as much as I wanted.

That’s when I decided to learn about intermittent fasting again. I experimented with a mixture of intermittent fasting methods for about 3-4 months while doing the fasting mimicking diet once a month. I lost 12 lbs! That was a miracle for me!

Intermittent Fasting Without Keto Video

In Summary

If you are looking for true food freedom, intermittent fasting is an excellent option and it works! It works because you will get your body into ketosis and your appetite will decrease. It will not only help you achieve your weight loss goal, but you will notice that you will have more energy and a better focus. Just remember, everyone is unique and what worked for me, may not work for you. You will need to keep experimenting to see what works for you. Don’t give up and realize that intermittent fasting is a lifestyle.