Many people begin intermittent fasting with one question in mind: What should I eat? But the twist is just as important. What should I avoid?
Let’s be honest, even a small mistake can ruin your results. This is especially true if you are trying to adhere to eating and fasting periods. And it’s not just about calories and counting. Some foods can mess with your blood sugar, trigger cravings, or make you hungrier than before.
But the good news? Well, once you know what the big problems are, it’s easier to avoid them and focus on the foods that make fasting possible.
Let’s take a look at what foods to avoid during intermittent fasting, why they’re important, and what you can eat instead.
Why can certain foods break my fast?
The important thing about fasting is that it gives your body a break from digesting food so it can focus on other things, like burning stored energy, controlling blood sugar, and reducing some inflammation. The problem is that some foods (And drinks, of course.) pulls you right out of that zone before you even realize it.
Sugary snacks are definitely one of the quickest ways to stimulate insulin. This can block fat burning and make you hungrier than before the meal.
The same goes for refined carbohydrates. Your body digests it quickly, your blood sugar spikes and then crashes. Suddenly, instead of just thinking about your next meal, you’re fighting cravings that feel urgent.
Additionally, fatty and heavy foods can be just as damaging. To be fair, they don’t necessarily raise your blood sugar in the same way that sugary snacks do, but they can tax digestion and cause a sluggish, heavy feeling that makes fasting the next day more difficult.
And yes, it is. Even “healthy” drinks like a smoothie or a fancy coffee order can sneak in enough calories to break your fast without you even realizing it.
If you want to reap the full benefits of intermittent fasting, it’s a good idea to know what to avoid while intermittent fasting and save those foods for the right time around your mealtime. That’s why my guide to foods to avoid while fasting will make everything clear.
Common foods to avoid during intermittent fasting
When people talk about intermittent fasting, the focus is usually on what to eat when mealtime opens.
Yes, it’s definitely important. But the flip side of knowing what foods to avoid during intermittent fasting is equally important. I’ve seen people fast all morning and then undo all their progress with one snack or drink they didn’t even think twice about.
The problem is that when you fast, your body is running at a different rhythm. Right? So your insulin levels drop, digestion stops, and you’re basically ready to burn fat for energy.
But did you eat the wrong food at the wrong time? You can throw it away in a matter of minutes. We’re talking about blood sugar spikes, the onset of cravings, and controlling hunger.
If you really want to get results while intermittent fasting, here are some big categories of foods you should avoid: And I’m not saying these foods are “bad” in general. Just know when to eat it and when it will harm you.
sweets and desserts
Let’s start by looking at the basic foods to avoid during intermittent fasting: sugar, snacks, and desserts. Candy, pastries, donuts – basically anything that contains sugar – can break your fast in just a few minutes.
These aren’t just empty calories. It has a direct effect on blood sugar. Once the spike occurs, your insulin levels rise and your body shifts out of fat-burning mode.
That’s why you often experience a quick burst of energy, followed by a crash that leaves you craving more and more sugar. If suppressing your appetite is important to you while fasting, save your desserts for planned snacks at mealtimes rather than during your fast.
refined carbohydrates
White bread, regular pasta, crackers – they may seem harmless compared to candy and the snacks mentioned above, but believe it or not, your body treats them much the same way.
They break down quickly, raise blood sugar levels, and don’t keep you full for long. To simplify, this means you will get hungry faster and fasting will be more of a mental battle and challenge than it needs to be.
If you have an open eating window, choose carbohydrates that contain some fiber and nutrients. It will provide steady energy instead of sudden bursts. You can always check out the intermittent fasting plan I wrote on my blog to get ideas.
Processed snacks and junk food
Chips, packaged crackers, fast food fries – these are double trouble. They are designed to be high in calories, low in nutritional value, and highly addictive.
It seems like all you have to do is grab a handful and move on, but suddenly your bag is empty and you’re wondering what happened?!
Additionally, these snacks and junk foods are high in sodium and unhealthy fats, which can leave you feeling bloated and sluggish. Not exactly how you want to feel after continuing your fast, right?
high calorie drink
This actually surprised you a lot. Creams, syrups, smoothies, sodas, energy drinks, and even alcohol-laced coffee can break your fast faster than you think.
To be honest, liquid calories are easily reduced but still trigger the same response in the body as solid foods. What does it mean? Well, this means the fat-burning pause button gets hit and your hunger can soar right away.
If you want to drink something during your fasting period, choose water, black coffee, or unsweetened tea. I know it’s boring. But it keeps you in the fasting zone.
final thoughts
One thing I’ve learned from watching people try intermittent fasting is that “what to avoid” is much easier to ignore than “what to eat.” But skip it?
As mentioned several times in this article, things can quickly go sideways. Choosing the right foods isn’t about being perfect. It’s all about stacking the odds in your favor so you’re not fighting cravings every two hours.
Eliminating common troublemakers like sugary foods, refined carbohydrates, processed snacks, and high-calorie drinks can make fasting feel lighter and almost easier because your body isn’t constantly racing and crashing. This is the point. Make it something you can actually stick to.
Yes, start simple.
Don’t forget to be consistent. Pay attention to how your body feels as you avoid things that hinder your progress.
And if you still need ideas to fill your mealtimes with good food that tastes amazing, we’ve got recipes and guides from around the world waiting for you here at Fit Men Cook.
FAQs about foods to avoid during intermittent fasting
Foods to avoid during intermittent fasting include sugary snacks, refined carbohydrates, fried foods, and processed junk foods. This can raise blood sugar, trigger cravings, and make fasting difficult to maintain.
Yes. Artificial sweeteners can sometimes trigger an insulin response that can break your fast. Although it has no calories, it can still affect hunger and cravings. It’s best to skip it during fasting periods.
The best foods to eat during intermittent fasting are whole, nutritious foods. That means it includes lean proteins, vegetables, healthy fats, and slow-digesting carbohydrates to support satiety and steady energy throughout mealtime.
Yes, that’s right. Foods that can make fasting more difficult include snacks high in sugar, refined carbohydrates, and greasy, processed snacks. This can cause energy crashes and more intense hunger during your next fast.
Safe beverages during intermittent fasting include plain water, black coffee, and unsweetened tea. Avoid sugar, milk and cream as they can break your fast.
