Intermittent fasting works for weight loss because you feed your body during the hours that it can best use the calories you consume for energy. Does it matter how much you eat or how many calories you consume when your eating window opens up? I’ll address those questions in this post.
Do Calories Matter When Fasting? Summary
- Fasting studies have shown that reducing the hours we consume food causes weight loss without conscious food intake restrictions.
- Consistent adherence to a fasting routine may reduce the need to count calories.
- You can lose your ability to recognize true hunger due to a poor diet, resulting in an increased need to track your calorie intake.
- Pairing intermittent fasting with a low carb/high-fat diet will give you a weight-loss edge and could reduce your need to track calories.
Do Calories Matter When Intermittent Fasting? [Video]
In this video, you’ll learn…
- The power of a consistent fasting routine.
- The importance of being able to recognize hunger.
- How to improve your intermittent fasting results with your diet.
Fasting Reduces Calorie Intake
Many of the intermittent fasting studies that have been performed showed that by merely reducing the number of hours during which participants consumed food, they lost weight. In many cases, there were no restrictions placed on the participants regarding what or how much food they could eat during their eating window (1).
In my book, Intermittent Fasting Diet Guide & Cookbook, I reviewed many of these studies. The obvious question that these studies lead us to ask is, “Does that mean calories are unimportant when you are fasting?”
In other words, can you eat whatever you want without consequences, as long as you eat everything within fewer hours? After all, it worked for the research participants. Let’s take a look at what it means to be in a study.
Participants in scientific studies are monitored to ensure that they are sticking with the research team’s fasting guidelines. These studies are carried out over several weeks or months, which means that the participants are fasting every day for long periods.
So we have to ask: “Did their consistent efforts reduce their need to count calories?”
We know that the human body likes routines and adapts when presented with a new one. For instance, if you have been a regular breakfast eater in the past, your body adjusts to your routine by producing digestive enzymes and triggering hunger hormones in anticipation of the meal.
If you switch up your routine by skipping breakfast, your body will continue to anticipate food at breakfast time for a few days, but it will soon adapt to your new pattern.
By sticking to a consistent fasting routine, it is possible that participants experienced less hunger during their fasting periods, which translated into a more sensible diet during their eating window and the observed natural decrease of calories over time.
Bottom Line: You will likely find that calories matter less when you adhere to a strict and consistent fasting routine because you naturally eat less without conscious effort.
Recognizing True Hunger Matters
It is worth noting that recognizing true hunger is a skill many of us have lost. The refined foods that makeup so much of the standard American diet get digested and absorbed quickly into the bloodstream. The resulting blood sugar spike is followed by an inevitable crash that brings hunger back sooner than expected.
On top of that, years of eating these low-value foods have left many of us insulin resistant, which means that even if we take in a lot of quick digesting calories, our cells resist the energy, and our cravings for more food never go away.
Bottom Line: If your diet was poor before coming to intermittent fasting, you might find it necessary to remaster the skill of recognizing true hunger. Until then, it’s a good idea to keep track of how many calories you are consuming.
What You Eat Matters
Another point to consider when you are questioning if calories matter when intermittent fasting is the macronutrient (i.e., carbohydrates, protein, fats) breakdown of your diet.
One of the benefits of fasting is that it puts your body in a hormonal state that favors fat burning. This is primarily accomplished by keeping the fat-storing hormone, known as insulin, low.
Insulin’s job is to shuttle food nutrients out of the blood and into the cells to be burned for energy. If there is no immediate need for energy, the excess gets stored as body fat.
When you fast, there is no food coming in, so insulin has no work to do. The result is a consistently low insulin level, keeping you in a favorable fat-burning state.
When you start eating, insulin rises in response to the food. But, how much of a rise depends on what you are eating. Foods high in carbohydrates, particularly refined treats and sugary drinks, will cause the steepest spike in insulin, protein will create a moderate peak, and fat will cause little if any rise in insulin.
Another advantage of eating fat is that it digests and burns slowly, keeping hunger under control. That reduction in hunger will help you to naturally and subconsciously eat less often.
Bottom Line: The hunger satisfaction and low insulin levels that result from pairing fasting with a low carb/high-fat diet will give you a weight-loss edge. If you are making the progress you desire, this way of eating may reduce your need to track calories.
Intermittent fasting has been shown to naturally reduce the number of calories you consume throughout the day, reducing your need to count calories.
However, to maximize this benefit, you’ll be happiest with your results if you adhere to a consistent fasting routine. If weight loss is your primary goal, you’ll help your body to lose weight by choosing low-carb/high-fat foods during your eating window.
And, if you are coming from a diet that was high in refined and sugary foods and drinks, you may have trouble recognizing true hunger, so calorie counting will benefit you until you feel more in control of your appetite.
Intermittent fasting can be a game-changer for you. It is the perfect complement to a healthy low-carb diet. I encourage you to pick up my new book.
Not only do I go over the best ways to fast, but I also share how to eat during your eating window to maximize your results. The book comes with more than 50 original recipes that will get you up to speed quickly. Thanks for reading!
(1) Gill, Shubhroz, and Satchidananda Panda. “A smartphone app reveals erratic diurnal eating patterns in humans that can be modulated for health benefits.” Cell metabolism 22.5 (2015): 789-798.
About the Author
Becky Gillaspy, DC graduated Summa Cum Laude with research honors from Palmer College of Chiropractic in 1991.