The Science of Motivation

What to Eat and Drink While Intermittent Fasting

As we dive deeper into the subject of IF, I recommend taking a moment to identify what your goals are.  Are you trying to maintain your weight, lose weight, or gain muscle while slimming down? It's important to know this going in if you want the best results.  IF is about stripping away body fat and that can be done regardless of what your specific goal is.

I personally recommend figuring out what your daily caloric needs are and tailoring that number (if necessary) to your goals.  Many people don’t know what that number is - I was one of them for most of my life.

For example; if, based on your age, gender, lifestyle, etc, your normal daily caloric needs are 2000 calories a day (see calculator here to determine your normal daily caloric needs), and you are trying to lose weight, you would calculate a number that would allow you to eat at a deficit of calories to your current number of 2000.  Let’s say 20% or 400 calories; you would then keep your calorie intake at 1600 per day until you get to your goal.

To maintain weight while losing fat, you would eat at your daily caloric need whatever that currently may be (given as 2,000 in the example).  

To gain muscle mass, while losing body fat, you would eat in excess of your daily caloric need, to support muscle development and the physical activity that goes with getting to that goal (example; add 20% to your normal daily caloric needs).

Also, please remember to consult with your physician should you have any questions on whether IF is right for you.

Thanks and enjoy the article!  - John


Intermittent fasting, as you probably know, is a type of eating pattern where you go through phases of eating and not eating. Not only do you need to know what you can have during the fasted state, but also how and when to eat when the eating period begins. This blog post is going to provide you with info for eating both while fasting and not fasting. 

So....what should we eat and drink while intermittent fasting?  IF will not work if you overeat once your fast ends (see note above).  You must eat to your daily caloric requirements.  Purge your diet of hollow calories, i.e. sugar-laden beverages and junk food.  Focus on items that will nourish your body for the upcoming fast period.  Technically, you can eat what you want on IF if you stay at or below your daily calorie need, but is doesn't make sense to blow all of your daily calories on junk if your are trying to get healthier.  Read on for more...

Don’t Overdo It

One of the biggest mistakes people make when following intermittent fasting is that they are counting the hours until they can eat, then they will overeat. The point is not to starve yourself for 20 hours just so you can binge eat for 4 hours. You want to stick to your normal diet, but eat in 2-3 larger meals, instead of constantly eating throughout the day. If you are restricting calories, continue to do so, but still stick to nutrient-dense meals. You want that food to fuel your body and sustain you for the next fasting phase.

Switch to No or Low Calorie Beverages

If you are just starting out with intermittent fasting, you might not know exactly what “fasting” entails. This does not mean you have absolutely nothing during the fasting window. Instead, you want to stay hydrated, so make sure you have plenty of water. You can also have no-calorie beverages like tea and coffee. Just be careful about what you add to your coffee. Some people allow themselves a splash of creamer in their coffee, since the calories is still extremely low, but try not to depend on that. If you really just want something else to drink like soda, stick to diet soda, but do not make this a habit either.

Stick to Healthy Eating

Many people make the mistake of using intermittent fasting as an excuse to eat what they want, then fast, assuming it will balance out and they won’t gain weight. This is the absolute wrong mindset to have, plus, you aren’t going to gain all the wonderful benefits of intermittent fasting if you choose this method. When you are eating after fasting, ease into it slowly, starting with a normal-sized, healthy meal. Your meals during a shorter eating window should be as nutritious as possible, with lots of vitamins and minerals.

Think lean protein, fruits and veggies, grains, nuts, and seeds. You may have one or two larger meals, but if you have gone 16-24 hours without a meal, you don’t want that first meal to be riddled with preservatives, sugar, and processed ingredients.

Check out the next post in the IF series:  Managing Your Intermittent Fasting Window