What to eat during intermittent fasting guide

Written by Trey Reck

Medically reviewed by Josie Porter, RD

“What can I eat during intermittent fasting??”

• Every intermittent faster since the dawn of time

There’s a short answer to that question:

You can eat whatever you like! 

That’s actually 100% true (though not necessarily 100% optimal). 

Intermittent fasting isn’t A Diet. It’s an eating style that structures your day — or week — into an alternating pattern of eating and fasting. 

Eat, fast, repeat. It needn’t be any more complex than that. 

And, there’s a long answer (this is where the optimal part comes in):

Eat more of the foods that’ll make your intermittent fasting into a powerful driver of health benefits, weight loss, revved-up energy, and snappy thinking. 

We suspect that’s the answer you’re really interested in.

We get it. You want to feel confident that your food choices compliment your fasting, rather than working against it. 

Let’s make sure that happens. Consider this your ultimate guide in what to eat during intermittent fasting. 

10 foods to eat while intermittent fasting

Everywhere you look, there’s information about what you should eat.

Some of it sounds plausible and jives with what you thought (“eat more fruit” sure sounds like something your grandpappy might have said). 

Some of it sounds like baloney (bulletproof coffee … really?!). 

Much of it falls between those two stalls (uhhh, are potatoes good or bad???) 

It can be hard to know what’s true. Add intermittent fasting into the mix, and you’re left wondering:

Can you really eat anything while intermittent fasting?   

You actually can. Intermittent fasting is an approach to eating that is more about when you eat than what you eat. 

But, if you want to feel your best, function well, and maintain a healthy weight, including certain foods in your day-to-day diet may accelerate your results. 

We can also help you figure out a meal plan that incorporates them. Check out our SIMPLE quiz to get started! 

Without further ado, here are 10 of the best foods for intermittent fasting. 

Whole grains

In the whole grain basket, we have the familiar:

• oats
• brown rice
• whole-wheat pasta

and the less familiar:

• quinoa 
• buckwheat
• freekeh 

Whole grains work great with intermittent fasting because their fiber content keeps you full and makes your digestion happy. 

Some of these probably seem like strange options (what on earth is freekeh?!) and you might not yet know how to use them. 

That’s OK. Try moving along the spectrum of grains starting with the easiest, friendliest looking option. Switch white rice for brown, for instance, or white pasta for whole-wheat. 

Then when you’re feeling brave, throw some freekeh into a salad or soup (it’s actually surprisingly nice. Kinda chewy!). 

Avocado

Heck, isn’t avocado full of fat? 

Why yes, it is. 

That’s exactly why it makes our “what to eat when intermittent fasting” list. 

Avocado is full of unsaturated fat — the healthy kind — and that fat content will help satisfy your appetite. A randomized study revealed what a humble avocado half can do (tl;dr: it’ll keep you full for hours).[1]

Legumes

Let’s start by decoding “legumes”. Nutrition professionals are very fond of them, yet they often feel a bit obscure. In real food terms, legumes are:

• lentils 
• peas
• chickpeas
• beans
• soybeans

They might make you a bit stinky (thanks, indigestible starch!), but legumes bring the fire to your intermittent fasting life by being full of nutrition yet low in calories, and their protein and fiber content helps keep you fuller for longer with more energy to boot.

Probiotics

Probiotics are live microorganisms (i.e., bacteria and/or yeasts that naturally occur in the body) that benefit our health when we eat them in adequate amounts, and studies suggest they may promote a healthy gut and support your digestion.[2]

They could also improve your ability to regulate blood sugar, with this study showing that pairing intermittent fasting with probiotics can improve your HbA1c (i.e., your average blood sugar levels for the last 2-3 months).[3] 

To get that probiotic boost, try adding a little fermented food like kimchi, live yogurt, or kombucha to your life. 

Fruits 

Your grandpappy was right, eating more fruit is a good thing. 

It’s one of the best foods to eat while intermittent fasting, because every fruit is a powerhouse of health in a tiny, colorful package. 

Fruit is packed with nutrients that help your body do its job. Whether you choose apples, berries, oranges, plums — you’re going to get a powerful hit of phytonutrients, vitamins, minerals, fiber, and carbohydrate, and your body will feel all the better for it. 

And, they’re low calorie, so when you replace other, higher-calorie foods with fruit, you get more food — and more nutrients — with less calories.

Dark-colored and cruciferous vegetables

Just like fruit, veggies have magical effects on our health.  

They help our gut, keep our digestion ticking over smoothly, keep us full and energized, and even give our mental health a leg up.[4,5]

To hit Next Level with your veg intake, loop in the darker-colored and cruciferous kind. All veggies have goodness in every little fibrous cell of their being, but veggies like: 

• broccoli
• kale
• cauliflower
• brussels sprouts
• chard

are amongst the best of the best foods for intermittent fasting, as they’re even more loaded with fiber and nutrients. (And they’ll keep you regular. Win win!)

Potatoes

We know you’re wondering. 

It’s time to put the “Can I have potatoes (while intermittent fasting)?” conundrum to bed. 

The answer is … Yes. 

White (and sweet) potatoes give you energy, are low in calories and high in nutrients, and fill you up for a good while.[6,7]

And, they don’t harm weight loss.[8] Promise. 

Fish and seafood

Foods from the sea contain impressive amounts of protein (think of all the muscle you’d have if you lived in water and had to outrun sharks all day). 

That enviable protein content, plus being high in healthy fat, makes fish and seafood an awesome example of what to eat on an intermittent fasting plan. 

It’ll keep you fuller for longer, help curb your cravings, and is a direct input into preserving your muscle mass. The more muscle you have, the more calories you burn during any activity, so you want to keep what you have (and, ideally, build more!). 

Eggs

Just like fish and seafood, the protein and healthy fats in eggs make them a solid choice when you’re intermittent fasting. 

Try them for breakfast and see how they affect your hunger through the day (these guys got good results).[9]

Nuts and seeds

If you’re noticing a theme here, you’re not wrong:

Foods that have high protein and are higher in healthy fats are those that hit the top spot over and over in our “what to eat while intermittent fasting” hall of fame.

Nuts and seeds are right up there as an important part of a healthy fasting diet.

Settle for small amounts because they’re high in calories, but don’t be scared to add them into your daily snack roster.

What can you have during your fasting window?

By now, you should feel pretty confident to answer the “What can you eat (and drink) while intermittent fasting?” question. 

Let’s move then, to this other crucial piece of the Faster’s Playbook:

“What can you have while fasting?”

Intermittent fasting works on one SIMPLE premise:

When you’re fasting, you don’t eat (or drink) anything with calories in it.

That gives you a very short, easy to remember list of things on your “what can I eat while fasting” crib sheet:

• black coffee
• tea without milk or sugar
• water

(Here’s a more complete rundown of fast-friendly beverages to answer all your What can I drink while fasting? questions.)

The bottom line is this:  

Any foods or drinks containing calories will break your fast. 

Now, if you’re following a plan like 5:2 or alternate day fasting (ADF), you have full fast days, not just for timed periods like with 16:8 or the warrior diet. On these days, you have 500/600 calories to play with. 

Use those calories wisely — the energy and fullness they give you needs to last you through the day. 

Our 10 foods above are excellent foods to eat while fasting on 5:2 or ADF, because they’ll stretch your 500/600 calories as far as they’ll go. See if you can include them in your fasting day meals and snacks.

Foods to limit or avoid during intermittent fasting

To be an intermittent faster who glides through their fasts with grace and poise (and without melting down into a hangry puddle of grouch), what you don’t eat matters as much as what you do. 

Some foods spike your cravings. 

Others make you hungrier. 

You probably have foods that, once you start eating them, you find it hard to stop. 

These are the foods to try and minimize (remembering that it’ll never be perfect and that’s OK).

What do those foods look like? Generally they have a few things in common. 

They’re usually: 

• Processed. They come in a bag, packet, or carton; they’re miles away from how they started out life — for instance, a bag of chips doesn’t look like a potato; a chicken nugget doesn’t look like a chicken — and they have many ingredients. 
• Full of refined carbohydrates. For instance, fruit juice, soda, bread, candy, cake, and desserts are full of sugar, high fructose corn syrup, and refined flour. 
• High in saturated and trans fats. Look for the words “partially hydrogenated oil” or “hydrogenated oil” on the labels to find these in your food. 

These are the foods that, when eaten too often, can undermine your fasting efforts and stop you getting the outcome you want. 

They don’t contain much nutrition, but they do contain some powerful combinations of fat, salt, and sugar that cleverly influence your brain chemistry to make you want to eat more (and more, and more…) of them. 

We know it’s not easy to give up foods like this. Simply try your best and see how it affects your progress if you eat fewer foods like:

• chips 
• soda  
• fruit juices 
• cake / pastries
• icecream
• processed cheeses and meats
• candy and chocolate 

Best foods for breaking your fast 

It’s time to break your fast! Yeah! 

Slow down there a moment. Don’t let your hunger or excitement drive the bus here. This is a time for smart food choices. 

Choose something you enjoy eating and which contains some slow-release energy, so that you get a steady, sustained build in energy rather than a fast spike followed by a fast crash. 

Here again you can choose from our list of 10 best foods for intermittent fasting. Try:

• an omelet with beans and broccoli 
• a chicken, lentil, and veggie soup 
• porridge (bonus points if you try quinoa porridge) with berries and a spoonful of nut butter
• a fruit, yogurt, and spinach smoothie (betcha don’t even notice the spinach)

Foods like these will start your eating window off strong.

Creating a fasting meal plan

If all these dos and don’ts are starting to sound like a lot to juggle — you’re not trying to create an eating routine fit for the circus! — an intermittent fasting meal plan may come in handy. 

Planning your meals in advance (usually on a daily or weekly basis) can not only help you make better food choices, but also ensure you’re meeting your nutritional needs. It also means you’re more likely to say sayonara to cravings, hunger pains, and last-minute food decision panic. 

The best meal plan for intermittent fasting is one that factors in your needs and preferences without stressing you out. You want what you eat to be enjoyable as well as nutritionally beneficial, after all! And if the idea of having a plan to set already sounds like “yet another chore,” maybe a meal plan isn’t the best choice for your food routine. 

If you want to give it a try, check out our guide on how to build a meal plan to get started. 

Is intermittent fasting for you? 

You’ve read all about how to plug great foods into your intermittent fasting meal plan. It’s about time we addressed the million dollar question:

Is intermittent fasting right for you? 

It’s not for everybody so, first up, let’s get clear on whether fasting is safe for you to try. 

Intermittent fasting is NOT recommended if you: 

• have a Body Mass Index (BMI) in the “underweight” category
• are under 18 yrs old
• have anemia
• have high daily physical activity demands
• have (or are at risk of having) an eating disorder, or a history of one
• have diabetes or a thyroid condition
• take medications (especially those which affect blood glucose or blood pressure levels)
• are pregnant, breastfeeding, or trying to conceive

If you’re on this list, it’s safer to avoid intermittent fasting unless you have your doctor’s express permission.

But if you’re not on this list, then it’s certainly worth a try. 

If you’re getting bogged down by the idea of fasting, thinking “heck, I could never go without food for so long!”, we’d encourage you to simply try it.  

Fasting usually sounds far scarier in our minds than it actually is in real life. You’ll probably find it a lot easier than you imagine, and there are many ways to hack hunger while fasting if that’s what’s holding you back. 

You’ll never know unless you try!

The methods available

The next question then, is this: Which fasting approach should you follow? 

The good news: They all work. It’s up to you. Which fasting schedule will suit your lifestyle best?

Let’s have a look at how each one works. 

(And if you’re looking for a little more help deciding what your best approach is, we gotcha! Try our SIMPLE quiz, and we’ll help you get started on your intermittent fasting journey today.)

Intermittent fasting 16:8

With 16:8 fasting, you’ll fast for 16 hours then eat within an 8-hour window. 

If you like to fast while you sleep and feel like fasting every day will slot in well with your family, work, and social commitments, this is a really nice intermittent fasting approach for beginners to start with.  

The warrior diet

On the warrior diet, the fasting window is 20 hours, followed by a 4-hour eating window. 

We’re not gonna lie — it’s gonna be hard to meet all your nutritional needs in such a short window. This one is more for the advanced fasters out there. 

The 5:2 diet

The 5:2 diet allows you to eat as usual 5 days per week, and on the other 2, you’d eat only 500/600 calories. 

You may prefer this two-day-per-week restriction, compared to a daily one like 16:8. It can fit more neatly into your life this way. But, an entire day with only 500/600 calories can feel pretty difficult. It’s swings and roundabouts with this approach.   

Eat Stop Eat

With Eat Stop Eat, you eat at least one full meal every day, by eating as normal on day 1, then fasting until the meal of your choice on day 2. 

This works out to be a 24 hour fast — a pretty significant chunk of time. At SIMPLE, we tend not to recommend it, because the odds of you developing some nutrient deficiencies with this method are fairly high. 

Alternate day fasting

Alternate day fasting is similar to 5:2 but more intense, as you fast one day and eat 500/600 calories on the next. This alternating pattern makes for three or four fasting days each week. If this weekly on/off style appeals to you, why not start with 5:2 and build up? 

Water fasting

As water fasting means going 24-72 hours with no food and drinking only water, it’s not a fasting protocol we recommend at SIMPLE unless you’re doing it with medical supervision. 

Written by Trey Reck

Medically reviewed by Josie Porter, RD