10 Things You Must Know About Intermittent Fasting

Intermittent fasting flipped the nutrition world on its head.

For years, we were told to eat small meals every few hours to “stoke the metabolism.” Then intermittent fasting came along and told us we have to eat all our meals in a 6-hour window.

Even though that advice is the complete opposite of what we used to believe, it has stuck around.

Today, I’m breaking down 10 things you need to know before giving intermittent fasting a shot. We’ll talk about what fasting is (and isn’t), when it works, who it works for, and who should probably stay away.

Let’s dive in.

#1 Autophagy

Whenever fasting comes up, someone always brings up autophagy.

Autophagy is your body’s built-in clean-up crew. It gets rid of damaged cell parts and replaces them with newer, healthier ones. Fasting has been shown to trigger this process in animals. Whether this holds true in humans is still unclear.

For what it’s worth, autophagy also happens with things like calorie restriction, exercise, and illness. So, fasting is not the only way to turn on this process.

Before we get into what fasting might actually help with, let’s break down what “fasting” even means, because not all fasting is the same.

#2 Not All Fasting Is Created Equal

Not all fasting methods look the same. Some are more sustainable, while others are a little extreme.

Here are two common styles:

• 16:8 (also called the Lean Gains method): You fast for 16 hours and eat in an 8-hour window. Most people skip breakfast and eat from, say, 12 to 8 PM. This one’s popular because it’s simple and doable.

• Alternate-Day Fasting (ADF): You eat normally one day, then either eat very little or nothing at all the next. Some people like the structure. Others find the hunger tough to manage.

Important note: Avoid dry fasting, which means not eating or drinking. That’s not just ineffective, it can also be dangerous.

Whatever method you choose, understand there will be an adjustment period. You’re changing how often you eat, not just what you eat, and that takes time to settle into.

#3 It’s Not a Magical Fat-Loss Hack

There’s a large group of intermittent fasting enthusiasts who think that if they fast for long enough, no amount of calories will affect them. Instead, they believe that fat loss is driven by hormones.

The myth goes as follows:

Fat gain is caused by hormones, mainly insulin, which is secreted when we eat carbohydrates.

Since insulin is the “storage hormone,” it is the main driver in fat gain. By abstaining from food during a prolonged fasting period, they believe there is no increase in hormones and no fat gain.

However, this oversimplified narrative is far from accurate.

Changes in fat tissue are fundamentally an energy balance issue (calories in VS calories out), independent of hormonal fluctuations. The idea that abstaining from food on one day can offset overconsumption the next is a misleading oversimplification; it's still a checks and balances game.

As a nutrition coach, I appreciate the practical applications of fasting. However, we need to dispel the myth surrounding its supposed exemption from the energy balance required for fat loss.

Understanding that fat loss is tied to energy balance allows for a more informed and realistic approach to intermittent fasting as a part of a broader nutrition strategy.

#4 Big Meals vs. Small Meals

Whether you eat five small meals or one massive one, your body isn’t keeping score that precisely.

Meal frequency does not make or break your progress. It’s about what works for your appetite, schedule, and preferences.

Let's say you want to distribute 2,000 calories between 5 meals at 400 calories each, and eat more frequently. You’ll see similar impacts on your metabolism and body composition as if you ate 1 meal at 2000 calories.

That said, eating fewer meals in a short window comes with some real challenges, especially when it comes to hitting your calorie or protein goals.

More on that next.

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#5 A Short Eating Window Can Make It Harder to Eat Enough

The goal is not to eat less. The goal is to eat enough of the right foods to support your body, especially if you want to build muscle, train hard, and recover well.

Let’s say your goal is 200 grams of protein per day. Try hitting that in just two meals. Not impossible, but not easy either.

You need time to prep, eat, and digest. And if you naturally don’t have a huge appetite, it can be hard to get enough in without planning ahead.

Think of it like studying for a big test. If you wait until the night before, you can try to cram, but you probably won’t do your best. Food works the same way.

Give yourself enough time to fuel properly.

#6 What About Athletes During Ramadan?

Here’s a real-life example: Athletes who fast during Ramadan go without food or water from sunrise to sunset for a month straight.

Sounds intense, but surprisingly, research shows that performance does not always suffer, at least not when athletes plan ahead.

They make it work by:

• Training during eating hours, when possible

• Focusing on high-calorie, easy-to-digest meals

• Getting enough protein and carbs

• Staying on top of sleep and recovery

Their example proves that with the right strategy, intermittent fasting can fit into a very active lifestyle.

#7 Fasting and a History of Disordered Eating Don’t Mix

If you’ve struggled with disordered eating or had a rigid relationship with food in the past, intermittent fasting might not be the best option.

When eating outside your “window” feels wrong or bad, it can be a slippery slope back into unhealthy patterns.

Your mental health matters. Nutrition should make you feel better, not worse. If you’ve got a history of disordered eating, check in with a coach or health professional before you try fasting.

#8 It’s Not a Free-for-All

Fasting doesn’t mean you can eat whatever you want in your window and still make progress.

Yes, shorter eating windows might help control calories, but the quality of your food still matters.

If you’re loading up on junk, skipping protein, and neglecting nutrients, fasting won’t save you. You still need to eat like someone who prioritizes their health and goals.

#9 Fasting Might Not Be Ideal for Muscle Gain

You can build muscle while fasting. But it’s harder.

To grow muscle, you need enough food, protein, and training. A tight eating window can make hitting those numbers feel like a job.

In my experience, the more traditional approach of spreading meals throughout the day is way more effective when your goal is to grow.

Trying to bulk while fasting is like trying to climb a mountain in flip-flops. Possible? Maybe. But you’re not making it easier.

#10 Fasting and Female Hormones

Fasting might reduce energy intake by default. That might sound like a win, but it can backfire, especially for women.

Low energy availability can mess with hormones, menstrual cycles, fertility, and overall well-being. This is especially important if you’re trying to conceive, pregnant, breastfeeding, or in any phase where hormone balance matters.

Even for women past reproductive age, low calorie intake can create unnecessary stress on the body.

If you’re female and thinking about fasting, make sure you’re still eating enough. Do not sacrifice long-term health for short-term goals.

Final Thoughts

Intermittent fasting is not a miracle solution. But it can be a helpful tool.

If you prefer fewer meals, struggle with grazing all day, or like eating bigger meals, it might be worth trying.

Just remember that it doesn’t replace the basics. You still need to eat enough, get your protein in, and be consistent.

Use it if it helps. Skip it if it doesn’t. The best nutrition plan is one that works for your goals and your life.