【A Schedule That Makes It Stick】How to Do 16:8 Fasting, Schedules for Every Lifestyle, Your 8-Hour Eating Window, and a 4-Week Starter Plan

“Intermittent fasting sounds hard… I’m not sure I could pull it off.”

Is that feeling keeping you from taking the first step?

The truth is, 16:8 fasting is getting attention around the world as one of the forms of intermittent fasting that even beginners can start without strain.

In this article, I’ll walk you through everything: how 16:8 fasting works, how to get started, what you can drink while fasting, and the common stumbling blocks.

What Is 16:8 Fasting? Understanding How Intermittent Fasting Works

16:8 fasting is an eating method in which, out of the 24 hours in a day, you fast for 16 hours and fit all your meals into the remaining 8-hour eating window.

Think of it like setting a shop’s “business hours”: your digestive system works for just 8 hours, and for the other 16 hours the shop is closed and resting.

It’s the most widely practiced form of intermittent fasting (IF), and it’s also called “16-hour fasting” or the “8-hour diet.”

Why 16 Hours?

It’s said that about 10 to 12 hours after you stop eating, the human body shifts into a “fat-burning mode” in which it turns stored fat into energy.

There are also research findings showing that once you pass 16 hours, autophagy (the cells’ self-repair function) becomes more active.

Autophagy is the process by which the body breaks down and recycles old cells and unneeded proteins.

You could call it a “big cleanup for your cells,” clearing out old parts and swapping in new ones.

When this function becomes more active, it’s thought to contribute to rejuvenation and health maintenance at the cellular level.

You Can Actually Get There “Just by Skipping Breakfast”

Hearing “16 hours without food” might make it sound pretty tough.

But in reality, the time you spend asleep counts toward your fasting time, so it’s much easier than you might think.

For example, if you finish dinner at 8 p.m., you complete a 16-hour fast simply by not eating anything until noon the next day.

How It Differs from Other Time Splits

Besides 16:8, there are several other time splits for limiting when you eat.

If you’re new to this, a comfortable way to proceed is to start with 12:12 or 14:10 and gradually work your way toward 16:8.

How to Start 16:8 Fasting and Decide on Your Fasting Hours

To actually start 16:8 fasting, the first important step is to choose a time window (the 8 hours when you can eat) that fits your daily rhythm.

Typical Eating-Window Patterns

The most common is the “noon to 8 p.m.” pattern.

Since all you do is skip breakfast and start with lunch, you don’t have to change your lifestyle much.

Recommended Schedules by Lifestyle

Even with the same 16:8 fasting, the time slot that suits you changes depending on your lifestyle.

What matters isn’t “which time slot is correct,” but whether you can stick to roughly the same time slot every day.

Eat Dinner Earlier, or Skip Breakfast?

Broadly speaking, there are two ways to create the 16 hours: “skip breakfast” or “eat dinner earlier.”

The skip-breakfast style makes it easier to enjoy evening meals with family and friends, and its advantage is that it’s easy to keep up.

The early-dinner style lets your digestive system rest before bed, so it suits people who want to improve their sleep quality.

If you’re unsure which one suits you, take a look at my article comparing skipping breakfast with eating dinner early as well.

How to Adjust on Days Off or Days with Plans

On days off, you may wake up later or have plans to eat out, which makes it hard to keep the same schedule as on weekdays.

On days like that, it’s fine to shift your eating window by an hour or two.

On days when you eat until late at night, such as at a drinking party, it’s easier to adjust if you push back your first meal the next day a little to secure your fasting time.

If your priority is to keep going, a “flexible” approach, sticking to 16:8 only on the five weekdays and relaxing on weekends, is good enough.

Use the First Week as an Adjustment Period

If aiming for 16 hours right from the start is hard, you can also begin with a 12-hour fast and gradually extend your fasting time.

Letting your body adjust little by little makes it possible to keep going without strain.

From my own experience trying it, the first 3 to 5 days were the toughest, and after a week my body settled into it smoothly.

A 4-Week Adjustment Plan

This plan is only a rough guide, so adjust it at your own pace while paying attention to how you feel.

If hunger or sluggishness gets hard to handle partway through, it’s perfectly fine to go back to the previous week’s hours and spend another week adjusting.

Even if you don’t reach 16:8 in four weeks, as long as you’re keeping up 12 or 14 hours, that alone is already a first step toward organizing when you eat.

The Complete Guide to What You Can and Can’t Drink While Fasting

With 16:8 fasting, choosing what to drink during your fasting hours is very important.

Be careful: if you have drinks that contain calories, the benefits of fasting will be weakened.

A Guide to What You Can and Can’t Drink

Basically, it’s simple if you just remember that zero-calorie drinks are OK.

Coffee is a strong ally during fasting, and it’s said to help ease feelings of hunger, too.

If you’d like to learn more about drinks, also read my article on drinks that are OK while fasting.

Tips for Easing Hunger with Drinks

When you feel hungry, slowly sipping warm tea or plain hot water tends to settle your stomach.

Sparkling water gives you a feeling of fullness, so it can help when you want to ride out a strong wave of hunger.

If you decide in advance when you’ll drink, like “one cup at 10, one cup at 11,” the time you spend thinking about hunger itself gets shorter.

Be Careful Not to Overdo the Coffee

Black coffee is a reliable ally, but drinking cup after cup on an empty stomach can upset your stomach or make you feel restless.

Also, caffeine late in the afternoon can make your sleep at night lighter.

I recommend keeping coffee to about one or two cups, mainly in the morning, and then switching to water or low-caffeine tea.

Make a Conscious Effort to Stay Hydrated

During fasting especially, it’s important to drink plenty of fluids.

Aim to drink about 1.5 to 2 liters of water or tea a day.

In hot seasons when you sweat easily, or on days when you exercise, it’s reassuring to make a point of drinking a bit more than usual.

Not getting enough fluids makes headaches and fatigue more likely, so build the habit of drinking a little at a time before you feel thirsty.

How to Plan Your 8-Hour Eating Window: What and How Many Times to Eat

Aim for 2 to 3 Meals in Your 8 Hours

With 16:8 fasting, it’s common to split your eating into 2 or 3 meals within the 8 hours.

For example, with the noon-to-8 p.m. pattern, an easy flow is your first meal at noon, a light snack around 4 p.m., and your second meal around 7:30 p.m.

That doesn’t mean you can eat as many times as you like within the 8 hours: if you keep grazing, your digestive system never gets to rest, and the benefits of 16:8 fade.

Start Your First Meal with “Protein and Vegetables”

If you break a 16-hour fast by suddenly eating lots of sweets or white rice, your blood sugar tends to spike.

For your first meal, the basic approach is to start with fiber from vegetables, mushrooms, and seaweed, and then get plenty of protein from meat, fish, eggs, and soy products.

Eat carbohydrates such as rice or bread last, in moderate amounts.

Simply changing the order you eat in to “vegetables → protein → carbohydrates” tends to make your blood sugar rise more gently even with the same menu, which also helps prevent afternoon sleepiness and sluggishness.

Make Your Last Meal One That Keeps You Full

The last meal of your 8 hours is an important one, since it comes right before you enter the next 16-hour fast.

A good balance of protein, fiber, and healthy fats keeps you full longer and eases hunger at night and the next morning.

On the other hand, if your last meal is carb-heavy, such as just a bowl of noodles or just a rice bowl, you’re likely to feel hungry early.

What to Choose When Eating Out or at a Convenience Store

Even when you eat out or use a convenience store, such as for lunch on workdays, a little thought about what you choose lets you keep up 16:8 fasting.

Be careful: if your meals keep being “just a rice bowl, noodles, or sweet pastries,” hunger comes back quickly and fasting tends to get harder.

A Sample Day’s Menu for the Noon-to-8 p.m. Pattern

16:8 fasting is a way of deciding when you eat, but getting the content of your 8 hours right makes it easier to get even more out of it.

Keep Exercise Light and Within Your Eating Window

Combining 16:8 fasting with exercise can be even more helpful for shaping your body.

However, while you’re still getting used to it, doing intense exercise on an empty stomach during your fast can cause lightheadedness or severe fatigue.

At first, I recommend doing things like walking, stretching, or light strength training during your eating window or just before or after it.

On days you do strength training, get plenty of protein from your meals to supply the building blocks for your muscles.

Common Early Stumbling Blocks with 16:8 Fasting and How to Handle Them

Many people who give up after starting 16:8 fasting hit a few walls in the first week or two.

Let’s go through the common stumbling blocks and how to handle them together.

1. Hunger Is So Strong You Can’t Concentrate

In the early days of fasting, hunger can make it hard to focus on work, or make you more irritable.

In that case, if you’re a night owl, try setting your eating window later in the evening, so it runs until just before bed.

If it’s still tough, adding a supplement is another option.

The one I actually used was a supplement called Unimate and Balance from Unicity, and it made hunger during my fast much easier.

2. You Overeat When Your Eating Window Opens

Some people end their fast, and when mealtime comes, the sense of release leads them to overeat.

It’s natural to want to eat as a reward for all the time you held back.

If you make a point of eating the first bite of your meal slowly, it becomes easier to avoid overeating naturally.

Eating something easy to digest first, like a salad or soup, before your main dish is also effective.

3. Your Weight Isn’t Changing

Even after you start fasting, your weight may not change much for the first two weeks or so.

This is a period when your body is adapting to a new way of eating, so it’s important to keep going without rushing.

After three to four weeks, it seems that in many cases people start to notice changes in their body.

If things still aren’t changing, check whether the amount you eat during your 8 hours, or your sugary drinks and snacks, have crept up.

4. You Feel Sluggish or Get Headaches in the Morning

While you’re not yet used to fasting, you may feel sluggish or get a headache in the morning.

This can be caused by a lack of fluids or salt, so one option is to drink a glass of water or plain hot water as soon as you wake up, and to replenish salt with something like miso soup.

If the symptoms are strong or last for several days, shorten your fasting time and see how you feel.

5. Your Mealtimes Don’t Line Up with Your Family’s

If you live with family, eating at different times from everyone else can mean you can’t sit down at the table together, which makes it harder to keep going.

In that case, I recommend resetting your 8-hour schedule to match your family’s dinner time.

If you let your family know, “I try not to eat after such-and-such time,” it becomes easier to get their cooperation.

People Who Should Hold Off on 16:8 Fasting

If any of the following applies to you, talk to a doctor or registered dietitian before starting 16:8 fasting.

If you experience dizziness, lightheadedness, or a severe headache, don’t push yourself: stop fasting and eat something.

Frequently Asked Questions About 16:8 Fasting

The Changes Your Body Goes Through and the Benefits You Can Expect from Ongoing 16-Hour Fasting

So what kinds of changes happen in your body when you keep up 16:8 fasting?

I’ll share my own experience along with the benefits that are commonly reported.

Changes in Weight and Body Shape

The change that’s easiest to notice is a change in weight.

In my case, after keeping up 16:8 fasting for three months, I successfully lost 15 kg (33 lb), going from 70 kg (154 lb) to 55 kg (121 lb).

Honestly, I was surprised that such a big change happened just from deciding when to eat, with no extreme dieting and no intense exercise.

A Clearer Head and Better Focus at Work

As I kept fasting, that foggy-headed feeling during work gradually went away.

This is thought to be because, without sharp spikes and crashes in blood sugar, the brain gets a steady supply of energy.

Many people seem to feel that their concentration improves especially in the morning.

Chronic Fatigue Becomes Easier to Shake

It’s said that when fasting activates autophagy, waste products are cleared from the body and fatigue is less likely to build up.

For me as well, the chronic tiredness I used to feel every day improved considerably within a few weeks of starting to fast.

If you want to learn more about the benefits, also take a look at my article on the benefits of 16-hour fasting and how to do it.

If you’d like to learn more about intermittent fasting, also see The Complete Guide to Intermittent Fasting.

▼ Watch the video version of this article