12 Intermittent Fasting Mistakes (& How To Avoid Them)

Intermittent fasting is one of the easiest ways to jump-start your fitness goals, but there are certain mistakes you should avoid if you want to achieve the highest levels of success.

So before you jump in, I want to help you learn what intermittent fasting mistakes you’ll need to watch out for (aka, the do’s and don’ts of intermittent fasting)!


16 8 intermittent fasting mistakes to avoid

This post contains affiliate links, which means if you click a link and make a purchase, I may earn a small commission at no additional cost to you. See the full details here.


What Is Intermittent Fasting?

In case you don’t know, intermittent fasting is a way of eating that restricts when you eat, rather than what you eat.

The most common approach – the 16:8 intermittent fasting plan – has you fasting for 16 hours of the day and eating all your day’s food in the remaining 8 hours.

For example, you might eat only between 12 pm and 8 pm, and fast from 8 pm to noon the next day.

Essentially just skipping breakfast.

It sounds super easy (and it can be) – but there are quite a few things that can trip you up if you don’t know what you’re doing.

It’s SO easy to make these mistakes… so let’s dive into what they are and how you can avoid them!


1- Not Drinking Enough Water

Perhaps one of the most pressing and easily avoidable intermittent fasting mistakes is not taking in enough water.

We know drinking water is important for overall health, of course, but it’s extra important when you’re fasting.

Why? Because much of the time when we think we’re hungry, we’re actually thirsty.

According to one study, nearly half of Americans don’t drink enough water.

Can you imagine how your appetite may be affected if you’re one of them while trying to go the bulk of the day without eating?

Luckily this is super easy to avoid!

Sneaking more water into your day is as easy as making a few simple tweaks.

Here are a few ideas for you to try:

  • Carry a water bottle with you wherever you go.
  • Drink a glass of water before meals and snacks to help you feel fuller.
  • Get creative with infusions, like adding cucumber or lemon slices to your water for added flavor.

Remember, you don’t have to overdo it with water consumption. Just gradually try to increase your water intake over time if you feel you aren’t already drinking enough, and you’ll be good to go!


Pro Tip For Getting More Water – Add A Flavor Enhancer!

Some people really get bored with drinking plain water. Believe me, I understand.

One thing I do is add a few Mio Drops to my water, and it makes a huge difference!

If you don’t know about these, Mio Drops are zero-calorie, zero-carb, sugar-free water enhancers that come in a tiny squirt bottle.

You just squeeze a couple drops into your water and you’re good to go!

You can find them at grocery stores, but I just buy mine on Amazon because it’s like a dollar cheaper per bottle.

I grab many at a time because I like to have different flavors. The Black Cherry is the best one, imo, but I also like Raspberry Pomegranate a lot too.


2- Doing Too Much, Too Soon

If you look around the internet, you’ll find different recommendations for how to start intermittent fasting.

My first day of intermittent fasting I went super hard, mostly by accident.

While I think this was okay since it was one of my earliest mistakes, I felt like it was too much to start.

I didn’t ease into it or give myself time to really gauge how I was feeling.

If I were to start intermittent fasting all over again from day one, I would not jump in that deep for my first fast.

I would aim for 16 hours and see how I felt.

I think moderation is important.


3- Artificial Sweetener

fake sweetener fasting

Will artificial sweetener break my fast”? Technically no.

Conventional wisdom has it that during your feeding window if you consume less than about 50 calories or so, you won’t completely break your fast.

Many people enjoy a splash of milk in their morning coffee and lose weight just fine.

But for artificial sweetener some people feel that it ignites the same pleasure center of the brain as real sugar, causing you to crave, thus making it harder for you to fast.

From personal experience I didn’t really find this to be the case, but I still think it’s something to be mindful of.

If you’re piling the Splenda into your morning coffee and wondering why you’re struggling to make it to your 12 o’clock feeding window, that might be why!

To avoid this, try your coffee black for a couple days and see if you can get with the taste.

It could also be that some people are more sensitive to any calories than others.

The artificial sweetener I use for my coffee is liquid sucralose, which truly has zero calories.

Like, zero, zero. It’s 600 times sweeter than sugar, so I just put one tiny drop into my cup (no milk) and I’ve never had a problem with it spiking cravings or hunger.

It’s one of my secret weapons for successful fasting, and since so very little goes such a long way, one 4-ounce bottle lasts me a year!

Crazy, huh?


4- Misunderstanding Hunger

should i eat if i'm hungry during fasting

One of the best things that I’ve taken from my intermittent fasting experiment is that I got to learn what real hunger is.

It doesn’t come at 9 am when you’ve been awake for an hour, and last ate a late-night snack at 11 pm the night before.

Like yeah, your stomach might be growling.

You might have a taste for something yummy.

It might be pleasant to sit down with your family or friends and enjoy the social aspect of dining.

But you aren’t really hungry.

Intermittent fasting teaches you that if you wait long enough (and usually just 5 to 10 minutes), most of the time your “hunger” will fade.

It’s probably happened to you many times before without you even considering it.

How many times at work have you meant to go eat but some pressing work-related task came up and an hour or two went by and you’d forgotten about your formerly grumbling tummy?

When you’re really hungry, you won’t forget about it.

But giving in and eating too soon is one of the big mistakes with intermittent fasting. Because if you just drink some water and give it 10 minutes or so, you’ll usually be just fine.

Don’t crash your intermittent fasting plan before you even get started.

Don’t make the mistake of giving in to false hunger!


5- Overeating

One of the most offensive intermittent fasting mistakes is adopting the attitude that says, “I’ve starved myself all day, I DESERVE to reward myself for dinner”!

Then go blast off with an insane amount of fattening, calorie-bombing junk.

Don’t be that girl.

You’ll feel miserable AND probably gain weight.

Totally not cool.

Though technically intermittent fasting isn’t a diet in that it doesn’t restrict what you eat, it’s still important to make food choices that are on the lighter side.

You can absolutely over eat and gain weight by eating only once a day if you’re eating more calories than your body burns.

While you don’t have to be a total stickler and there’s room for flexibility, be smart.

Do yourself a favor and don’t go nuts during your feeding window.


6- Not Eating Enough

intermittent fasting 30 days one month what to expect

On the flip side, if you’ve yet to try intermittent fasting before this may seem counter-intuitive.

But for many fasters, when you don’t eat for an extended period of time you actually become less hungry.

I think that’s why I was able to fast for 24 hours on my first day.

And why if you look around (like in Reddit’s r/fasting forum) you’ll see people doing really freaking super long fasts like 4 weeks and such.

Fasting can totally kill your hunger.

Unless you’re intentionally doing an extended fast (not recommended for beginners), though it’s really easy to do so, it’s not a good idea to under-eat either.

If you under-eat long enough, you can totally wreck your metabolism and throw your hormones out of whack.

Furthermore, you’ll deprive your body of essential nutrients, which can lead to health issues that are far worse than carrying a few extra pounds.

Consult with your doctor about an ideal calorie range for weight loss and make sure you’re somewhere around that range most days for optimal results.


7- Failing To Plan Your Meals

While calorie counting isn’t necessary (though honestly, you’ll get better results if you do it), having a rough idea of how you’ll break your fast is an incredible intermittent fasting hack.

By delaying when you eat, you’re allowing yourself time to be less impulsive.

Instead of going “I’m STARVING and have to eat NOW”, then swerving into the nearest fast food drive-thru lane to kill that hunger ASAP, you’re learning “meh… I feel hungry, but I can wait”.

Using this time to consider what you’ll eat when you eat, and making more nourishing choices only helps you in the long run.

It teaches you how to eat for successful weight loss, while reducing caloric intake, keeping you nourished, and boosting your confidence.

If you’re fasting for 16 hours, you can take as little as 5 minutes to plan how you’ll break that fast later.

It’s really not that hard and will pave the way for a slimmer future!


8- Not Exercising At All

exercise intermittent fasting one month

One of the biggest intermittent fasting mistakes you can possibly make if you’re serious about losing weight is failing to exercise.

While it’s true you could still lose quite a bit of weight intermittent fasting if you never worked out, why would you miss out on the incredible opportunity to lose even more, faster?

It really makes no sense.

Time is time. A month is a month.

If in one month you could be lazy and lose 5 pounds or workout three times a week and lose 10, wouldn’t you prefer the ten?

I know I would!


Working Out Works!

I mean I get it, working out isn’t fun. It’s a bit time-consuming and it hurts afterward if you’re going hard.

But the beauty of intermittent fasting is you don’t have to work out as much.

Your diet takes care of the rest.

During my month-long 10-pound weight loss intermittent fasting experiment, I worked out but very minimally.

Far less than normal. But I think the bits and pieces I did, helped.

Furthermore, light to moderate exercise during my fasting window made me LESS hungry.

It was much easier to make it long stretches of time on days I worked out versus days I hadn’t.

One caveat, however, is that heavy exercise while fasted may be a bit much. Keep it light to moderate, but DO IT.


9- Failing To Develop Wholesome Eating Habits

intermittent fasting grocery list beginners

Take it from me, you want to use the ease of intermittent fasting to focus on developing good habits for the long haul. Failing to do so is one of the biggest fasting mistakes ever.

Because while intermittent fasting does work, if you ever decide to quit or fall off, if your diet isn’t in order you will gain back every last pound!

Some people have amazing staying power and have incorporated 16:8 intermittent fasting into their lives permanently.

I think that is impressive and amazing and I know they feel great, lead simpler lives and look incredible.

But I found it to be too much and within a couple weeks of quitting, I gained back all but two of the pounds I’d lost.

I was so excited to have lost the weight, but I didn’t take advantage of the process.

I didn’t take that time to change my dietary lifestyle, grow accustomed to eating differently, and build a positive habit that would sustain my weight loss no matter what time of day I ate.

If you do not develop favorable habits for life you will not make it.

Intermittent fasting is probably the closest thing to an effortless weight loss trick you’ll ever find.

But you still have to be mindful and work each day toward real change.

Keep that in mind.


10- Telling Too Many People

This intermittent fasting mistake won’t really have an effect on your weight loss, but more your morale.

The fact of the matter is most people are ill-informed about intermittent fasting and don’t really understand what it is.

They think its gimmick, a fad, or an starvation diet of some kind.

Without researching though, nobody really knows what to think. So, it’s not their fault.

But if you’ve been on the weight loss roller-coaster for a while, your friends and family may already be skeptical of you getting it right “this time” and following through.

They may have seen you crash diet before, only to gain the weight back.

Or they may be genuinely concerned for your health if they think you’re heading toward an eating disorder.

Malicious intent or not, negative attitudes surrounding your new intermittent fasting journey are no good.

At worst they’ll make you second-guess your decision to give it a try. Or shake your self-confidence on whether you can pull it off.

At the very least you’ll be beyond annoyed!

Discussing your new way of eating with everybody too soon is one of the biggest fasting mistakes.

Shake the weight first.

When they say, “girl you look amazing, what are you doing”?

THEN you share.

Let your results speak for themselves.


11- Choosing The Wrong Schedule

fasting schedules for weight loss

In my Intermittent Fasting FAQ (question #2 to be exact), I went into detail about the different types of intermittent fasting programs and schedules.

Just because 16:8 is the most popular doesn’t mean it’s right for you.

Choosing the wrong program for your goals and lifestyle can be one of the most unfortunate mistakes out there!

You could ruin your chances of success before even starting.

Do yourself a favor.

Take your time, do the research and follow a plan that makes the most sense for you and your life.

One of the greatest benefits of intermittent fasting is that it’s flexible.

Take advantage of that flexibility and make it work for you!


12- Giving Up Too Soon

Finally, giving up too soon is one of the intermittent fasting mistakes made most often.

It’s possible that you aren’t getting the results you expect, so you just throw in the towel.

I get it. It’s demoralizing to see others crushing it while you struggle on the sidelines.

Keep in mind that intermittent fasting isn’t for everybody. But if your only reason for quitting is that you aren’t losing weight, step back and evaluate your circumstances.

Could it be that you’re still eating too much for the amount of energy you burn daily?

Could it be that you are getting smaller but it’s just not showing up on the scale?

Have you given it enough time?

Just because one woman loses 5 pounds her first week doesn’t mean you will. Your moment may be just around the corner, but you’ll never experience it if you quit too soon.

Give it at least a few weeks before determining whether or not it’s for you!

And be willing to make little tweaks if you’re not getting the result you expect.

It just might be the thing that changes your entire life.

UPDATE: 10 Reasons Why You Aren’t Losing Weight On Intermittent Fasting (And What To Do About It)


Final Thoughts – Fasting Mistakes

I hope you’re not too overwhelmed by learning about these common mistakes with fasting! I promise it’s not as intense as it may seem.

It does take a little getting used to because if you’ve been eating whatever, whenever, for all your life then choose to go without food all of a sudden, you’re bound to experience some resistance.

I promise you, however, that if you try it it’s SO worth it!

Imagine a life where you’re free from excess pounds, obsessing over food, understanding true hunger, and feeling naturally energetic, light, uplifted, and empowered.

All of that can be yours if you’re willing to believe in yourself and invest the time, energy and resources into doing the dang thing!

I know you can do it – and I hope that you know it too.


Oh and by the way…

fasting 12 hours before after

If you’d like to get started with intermittent fasting or you want to take your intermittent fasting weight loss to the next level, what you really need is my Intermittent Fasting Weight Loss Planner! 

It literally has everything you need to track fasting, strength & cardio training, pounds/inches lost, space for notes, slots for before & after pics, and three 30-day fitness challenge charts! 


Happy fasting! 🙂


Read These Related Fasting Posts Next

Alex from Eat Those Plants
Alex from Eat Those Plants

My name is Alex and I'm a passionate advocate of a whole food plant-based lifestyle. Since losing over 40 pounds on a vegan diet I've created the Eat Those Plants website to help you look good and feel great by putting more plants on your plate!