Tapping Into Ancestral Hunger, Part 2: Top Hacks for the 24 Hour Fast - Unlocking Insights - Explore Our Articles (2024)

Believe me when I say that the first time I heard of purposefully foregoing food for an entire day, I was more than apprehensive. (I can recall one other time that I’ve done this in my life: after a very regretful trip to the buffet!). After actually fasting for 24 hours, I was pleasantly surprised by both the results of the fast and by myself.

It's part2 of this blog series on intermittent fasting (IF), and we'll present the basics of the 24-hour fast, hacks to help you successfully fast, and the top pros and cons of this IF method.

24 Hour fasting: Calorie restriction = Weight loss

Brad Pilon, author ofEat Stop Eat, says, “Prolonged calorie restriction is the only proven nutritional method ofweight loss.” [1] While much confusion surrounds diet trends and recommendations, if such a thing as an irrefutable truth exists in thenutritionworld, this fact would be it.

To lose weight, a negativeenergybalance is required. [2] In other words, you must expend more calories than you consume so you can eat less, exercise more, or better yet, combine the two to achieve weight loss.

» Curious about autophagy? See what you should know before starting a fast

Why I chose the 24-hour fast

For many of us, restricting calories is hard, especially in the long term. I picked the 24-hour fast because I find it easier to control myself completely for one day a week than to give up foods I love day after day. It’s important to note that you should still be eating within reason on the other six days of the week.

For example, if you need 2,000 calories daily, eat 2,000 calories six days a week and fast for one day. Don’t think you can now eat 4,000 calories six days a week, fast for one day, and still lose weight.

But wait, I have some concerns about fasting for 24 hours!

Won’t my metabolism decrease if I don’t eat for 24 hours?

Yourmetabolismis dependent on your body weight and, in particular, depends on yourleanbody mass. Contrary to popular belief, several studies have shown that fasting less than 72 hours will not affect your basal metabolic rate. [3, 4]In short, no. You won’t slow down your metabolism by fasting for a day.

Won’t I lose my hard-earned muscle?

When you fast for 24 hours, your body first uses the sugar stored in yourliverfor energy and then relies onfatstores.You’ll actually be burning fat instead ofmuscle!There is a small catch, however. To maintain muscle, you must do resistance exercises such as weightlifting. (This does not have to be on your fast day). Now that we’ve cleared the air on those concerns, let’s get into more detail.

The rules: How to do a 24-hour fast

1. No foods are off the table

You still have to eat within normal means during your six feeding days. Eat sensibly and as healthy as possible, but don’t feel restricted.

» Looking to revamp your diet? Check out these new foods to add to your diet

2. No calories during the 24-hour fast

Calorie-free drinks are allowed and encouraged!That means there’s no need to foregocoffee(the five calories in your creamer are fine), tea, or evensugar-free gum.

3. Break the fast with balance and reason

Break the fast with a regular-sized meal. Though there are benefits to IF beyond calorie restriction alone, you won’t lose much weight if you shovel down a day’s worth of calories each time you break the fast.

(You spent the day helping to reset your appetite thermostat. Take advantage of that fact, and remember to reframe your hunger perspective.)

4. More does not mean better

Suppose you can fast one whole day a week, great. If you can do this twice a week, it will give you more power. However, limit your IF to a maximum of two days a week.

5. Keep pumping iron

If you want to maintain muscle, make sure to continue weight training.

Pros of the 24-hour fast

• It is incredibly simpleNo complicated meal plans or prep is involved. For one day, once a week, you stop eating.
• It’s non-restrictiveThe other six days of the week, you live your normal life.
• It’s maintainable and sustainableI can see myself fasting for one day out of the week for the rest of my life. Since the success of any diet is largely contingent on whether people can adhere to its rules, success depends on the long-term maintenance of calorie restriction. I believe that many people would be able to practice the 24-hour fast for a very long time.
• PerceivablecognitivebenefitsDuring the later hours of my fast (think 16-24 hours), I felt like I was seeing the world in a new light. I felt sharp and focused on whatever task was at hand.
• ExcellentappetiteregulationAfter 24 hours of fasting, my appetite regulation was superb. While I thought that the opposite would occur (and that I would ravenously eat everything in sight), fasting for a day actually helped curb my appetite. I was no hungrier after one day than I sometimes am three hours after a meal.
• I regained self-controlI constantly talk about how ‘hangry’ I get when I don’t eat, but I realized that food doesn’t control me. I decided not to eat for 24 hours and was just fine.
• You can build up your toleranceWhile it might initially be difficult to fast for 24 hours, it gets easier with practice.

Cons of the 24-hour fast

• Twenty-four hours without food can feel very long, especially initiallyMany people worry about becoming ‘hypoglycemic’ or getting ‘low blood sugar’ if they don’t eat every few hours. This is largely psychological. Research suggests that unless you have a metabolic disease such as drug-treated diabetes, hypoglycemia is rare. [5] During a 24-hour fast, most healthy individuals can maintainblood glucosein the normal range.
• Potential headachesThe first time I fasted for a day, my head hurt a bit in the later hours of the fast. However, I didn’t have any problems the second time I fasted, and a combination of slowly increasing your fasting periods and staying hydrated can keep headaches at bay.
• Beware of post-fast binge-eatingAfter the first two times I fasted, I binged and broke my fasts with meals of around 1200 calories. Be wary, and don’t go crazy breaking the fast. Eat a normal meal as if you had not fasted at all.
• Your breath stinksDespite staying extremely hydrated, this is just inevitable after a day of fasting.
• Elite athletes and endurance athletes should think twice about the 24-hour fastIf you are an elite athlete training multiple times a day, are participating in some type of prolonged endurance sport, or are involved in any activity where performance is essential, the 24-hour fast is likely not right for you. [6]

» Explore why insulin is your key to metabolism and healthspan

Changes in weight after fasting for 24 hours

Be patient with the scale.The day after the fast, you will see the number on the scale drop significantly (anywhere from one-half to three pounds). [6] While much of this is water weight, you still lose fat. [7] After feeding normally for a few days, your weight will increase (to not quite baseline) as you regain body water. However, this doesn’t mean that you aren’t losing weight.

You're instead decreasingfatat a slow, sustainable rate. While the amount of weight lost depends on body size, short-term fasting has been shown to help individuals lose around 2% of their initial body weight after about three weeks of fasting. [7] Furthermore, in addition to weight loss, IF can be used to maintain weight loss in the long term.

Golden rules of intermittent fasting success:

• If you decide to try IF,stay in tune with your body!Fasting may require more adjustment for some than others; make sure you give your body time to adapt, as it may not be for everyone, and nothing is wrong with that.
• Stay busy. Don’t torture yourself by sitting on the couch and thinking about food all day. Instead, take some time to clear your head and get your body moving. Go for a walk or catch up with friends.
• Hydrate, hydrate, and hydrate.Water, tea, coffee… keep the liquids coming.
• Re-think your hunger.

My takeaways from the 24-hour fast

Financially speaking, I have no skin in the IF game. However, as both a self-declared spokesperson for wellness and a serious skeptic about the latest dietary trends, I would be ecstatic if you tried the 24-hour fast. I found IF not only to agree with my lifestyle but also to give me a sense ofempowerment.

As it hasn’t been three months since my last blood test, I can’t yet report on any of my biomarker changes. Suppose my mood and appetite regulation improvements indicate changes in my InsideTracker results. In that case, however, I expect to see improvements in my blood glucose levels and a drop in my Inner Age.

Effects of doing regular 24-hour fasts

I can say that I have regained control over my eating habits, have obtained a new perspective on the benefits of ‘hunger,’ and have even rediscovered what it feels like to appreciate food. After four rounds of the 24-hour fast, my clothes fit better. While I don’t like feeling restricted, I am plenty willing to fast once a week for the results I desire.

Check out part 3 of the blog series, where I’ll share my experience with the Breakfast Skip, an alternative IF method. In the meantime- what have you got to lose besides a couple of pounds?

References:

[1] Pilon, B. (2012).Eat Stop Eat(5th ed.). Strength Works, Inc.

[2] Deighton, K., Batterham, R., & Stensel, D. (2014).Appetite and gut peptide responses to exercise and calorie restriction: The effect of modest 2 energy deficits.Appetite,81, 52-59.

[3] Verboeket-Van De Venne, W., Westerterp, K., & Kester, A. (1992).Effect of the pattern of food intake on human energy metabolism.British Journal of Nutrition,70, 103-115.

[4] Keim, N., & Horn, W. (2012).Restrained Eating Behavior and the Metabolic Response to Dietary Energy Restriction in Women.Obesity,12(1), 141-149.

[5] Eckert-Norton, M., & Kirk, S.Non-diabetic Hypoglycemia.The Journal of Clinical Endocrinology & Metabolism.

[6] Pilon, B. (2012).Eat Stop Eat(5th ed.). Strength Works, Inc.

[7] Heilbronn, L, et al. (2004).Alternate-day fasting in nonobese subjects: Effects on body weight, body composition, and energy metabolism.The American Journal of Clinical Nutrition,81, 69-73.