Intermittent fasting 16:8 — an expert guide for success

Written by Trey Reck

Medically reviewed by Josie Porter, RD

Published on November 18, 2022 | Updated on March 28, 2024

If you’ve considered improving your eating habits, you’ve likely wondered about intermittent fasting.

It’s a method that captures our attention, because it’s so SIMPLE: Some of the time, you eat. Some of the time, you fast (i.e., don’t consume calorie-containing foods or drinks).

There are different ways this can shake out on a day to day basis. Today, we’ll walk you through intermittent fasting 16:8 — one of the most uncomplicated intermittent fasting methods.

It’s effective too: Research shows intermittent fasting delivers a host of health benefits from lowering your blood pressure to keeping your brain happy.

If you want to cut the clutter around eating with some straightforward guidelines that make room for your needs, preferences, and goals, you’re in the right place.

What is 16:8 intermittent fasting?

16:8 intermittent fasting is SIMPLE: 

• For 16 hours a day, you’re fasting. (This isn’t as scary as it sounds.)
• The remaining 8 hours, you eat and drink what you need to nourish your body, mind, and spirit.

We hear you — 16 hours sounds a long time.  It conjures mental images of tedious, never-ending shifts at work, and that family dinner that felt like 16 hours, because when you get cornered by Uncle Blake time just seems to … stop. 

A 16 hour fast isn’t like that. In fact, you’ll probably be asleep for roughly half of it. 

If you can make peace with eating an early dinner or a late breakfast, you can excel at 16:8 intermittent fasting.

Huh. That doesn’t seem so hard.

How to plan your 16:8 fasting schedule

Start by asking yourself some questions. 

• Which meal is most important to you? 
• If I miss breakfast or dinner — or if it’s late or early — what’s that like?
• When am I most hungry during my day? 
• Are there times when food is more necessary or convenient due to work, family, exercise, social events?

Gather some data on what you notice about your own patterns. Then, choose when you want your fast to begin and end. 

Say you shoot for a late breakfast and early dinner. Your fasting period might be 7 PM to 11 AM. 

If, however, you cannot skip breakfast without turning into a Very Unreasonable Person due to lack of food, you might prefer 5 PM to 9 AM. 

Ultimately, you’re looking for a 16:8 fasting schedule you can live with, because following a predetermined plan both feels better and makes it easier to stay consistent.

SIMPLE top tips: 

1. Schedule your fasting period when you are generally less hungry. This works with your appetite and reduces the possibility of hunger pushing you to break your fast early or eat more than you need.
2. Include your sleep hours in your fast. (We probably don’t need to tell you that if you don’t, you’ll need to master eating while you sleep, which is — as far as we know — impossible.)
3. Let us help you get up and running by trying our quiz. We’ve supported a lot of people to try intermittent fasting, so you’ll be in good hands. 

What should you eat on a 16:8 intermittent fasting plan?

When it comes to what to eat during intermittent fasting 16:8, there’s good news: 

16:8 intermittent fasting works with any eating plan. 

• During your fasting 16 hour window, eat nothing and drink only calorie-free drinks, like water and unsweetened tea or coffee. (Fancy coffees may be OK, if they fit your goals.) 
• Focus on the timing of your eating window to help your body adapt to eating all your meals inside eight hours.
• Close your eating window eight hours after you break your fast. 

Done!

Now, being more mindful of your food choices will help you squeeze out the 16:8 fasting benefits, especially for goals like weight loss or improving your metabolic health.

To optimize your 16:8 intermittent fasting results, shoot for high-quality foods like colorful veg, quality protein, and healthy fats in your meals. You can also check out our 16:8 intermittent fasting 7-day meal plan for beginners to get started on your journey.

Is a 16:8 fasting schedule incompatible with breakfast?

Not at all!

Whether you can’t face anything more than a slosh of water to rinse your toothpaste first thing or you’re a breakfast connoisseur, no worries. 

Tailor your fasting schedule to fit your life. 

5 tips for 16:8 beginners

The intermittent fasting 16:8 method is straightforward, yet it’ll likely feel clunky at first as you mesh it with your eating patterns. 

These steps will help you get into the groove.

• Make your fasting window work for you. If a healthy dinner with your partner is a deal-breaker, adjust breakfast-time to accommodate. And so on. 
• You’re likely to feel hungry in the beginning. Don’t worry, your body will adjust. Have some options ready to roll to distract you, like: 
  • playing a game 
  • listening to music
  • moving your body
  • drinking calorie-free drinks
  • doing a short meditation
  • getting some fresh air
• Stay hydrated, and shoot for a balanced diet of complex carbs, lean proteins, and healthy fats.
• Listen to your body. If you feel lightheaded, ill, faint, or shaky, 16:8 fasting might not be for you. If so, don’t worry. Maybe try a shorter fast, like 12:12 or 14:10. There are always other options. 
• Don’t be scared to make mistakes. You won’t get this perfect first time around. That’s OK. Here’s a few common intermittent fasting mistakes to get you ahead of the game. 

If you’re female, be aware that intermittent fasting for women and hormones is A Thing and you could have an adverse physiological response to fasting longer than 12–14 hours. To keep you safe, start with a 12-hour fast, slowly work your way up to 16, and always listen to your body.

16:8 intermittent fasting and weight loss

Let’s look at the benefits of 16:8 fasting on weight loss. Are there any?

Heck yeah! 

Diets don’t work. Studies show they don’t generate lasting or significant results.[1]

But intermittent fasting isn’t a diet. 

There’s no calorie restriction, deprivation, or gimmicks like “you may only ingest raw cabbage that’s been grown in the soil of an ancient forest”. 

It’s a lifestyle transformation. That makes 16:8 fasting weight loss results more sustainable. It’s an approach you can stick with long term.

16:8 intermittent fasting results

Strap yourself in — we’re going to lay some kickass real life and science-backed results on you. 

Could you achieve a lower body weight without counting every calorie [yawn] through intermittent fasting? Studies show you could.[2]

Curious to know whether intermittent fasting helps with burning fat? It does! In the study, people who fasted reduced their waist circumference and belly fat.[3]

A 16:8 intermittent fasting plan can also help you maintain muscle mass. (In fact, intermittent fasting might even be more efficient at maintaining muscle than traditional diets.)[4]

If you’re hungry for evidence, check these studies to see more intermittent fasting 16:8 weight loss success examples.[5]

Risks and benefits of 16:8 intermittent fasting

Everything has positives and negatives, intermittent fasting included. 

The benefits

So, is fasting actually good for you? 16:8 intermittent fasting packs some profound health benefits. For instance, intermittent fasting can lead to:

• Improved insulin sensitivity

There’s a well-established link between insulin sensitivity and weight loss, but recent research shows intermittent fasting improves insulin sensitivity even without weight loss.[7]

Research also indicates intermittent fasting has potential to treat type two diabetes. In this study, intermittent fasting helped patients improve their insulin resistance, maintain healthy blood sugars, and wean off their glucose-regulating medications.[8]

Important note: If you’re taking diabetes medications, talk with your doctor before you begin an intermittent fasting protocol.

• Lower blood pressure

In 2016, approximately 100 million Americans had high blood pressure (also known as hypertension, this is when your blood pressure is 140/90 or higher) [9], which is a risk factor for many diseases, including cardiovascular disease, stroke, and kidney disease. Here’s the good news: Current research shows intermittent fasting has potential to lower high blood pressure.[10]

• Improved cardiovascular health

Your heart health depends on multiple factors, including your weight, blood pressure, cholesterol levels, and blood sugar levels, all of which intermittent fasting can improve. A 2020 review hypothesizes that intermittent fasting also improves cardiovascular health factors through oxidative stress reduction, circadian rhythm normalization, and ketogenesis.[11]

• Lower risk of metabolic disorders

Intermittent fasting can help with your weight loss goals via the metabolic pathways activated by fasting, like ketogenesis, which in turn can help lower your risk of metabolic disorders, like type 2 diabetes.[12]

• Improved brain health

through inducing ketosis (increasing neuroprotective protein production) [13], increasing neuroplasticity (helping your brain make more connections) [14], and more generally through helping us reach our health goals, which are often deeply mentally and emotionally important. Animal studies suggest intermittent fasting can also protect your neurons [15], and increase autophagy (helping new cells to grow) [16], but naturally studying this effect in humans is tricky. 

Intermittent fasting may also help keep your spirits up.[17] If you want a brain that thinks good and feels good, maybe this benefit of 16:8 fasting will encourage you to get started!

The risks 

Though the benefits are plenty, there are some possible risks.

It’s best to avoid intermittent fasting if:

• you’re pregnant
• your BMI is in the “underweight” category
• you’re breastfeeding
• you have an eating disorder or a history of one

Important note: If you have type 1 diabetes or a history of disordered eating, intermittent fasting can be possible, but please, if you try it, make sure you are fully supported by a healthcare professional. Don’t go it alone.

You may also experience:

• Weight gain

Hold up … doesn’t intermittent fasting help with weight loss? Yes. However, if you end up feeling overly hungry during your fast, it can be easy to eat more than you need. 

• Hunger

Initially, you may feel ravenous, but you can overcome this with time, practice, and thoughtfully scheduling your fasting and eating times. 

As you’re going through this natural hungry stage, try some ways to hack hunger while fasting, like making sure to drink plenty of fluids, finding ways to distract yourself, and reassuring yourself that you won’t feel this way forever. 

• Feeling cold

Fasting can make you feel chilly, but it’s less likely on the 16:8 protocol than more restrictive schedules like 5:2. If you feel cold, again, know that it’s temporary. Throw on an extra sweater and trust that this effect will disappear as you adapt.

• Mild dehydration

Because food provides some of your fluid intake, you can get dehydrated during your fast. So, drink plenty. What can you drink while fasting? Focus on calorie-free drinks like tea with no sugar or coffee with no milk. And remember to drink enough water. 

Pros and cons of intermittent fasting 16:8

Let’s sum this up in a nice, quick, scannable list. 

The pros of intermittent fasting 16:8:

• is SIMPLE, easy, and flexible;
• can be helpful in reducing unwanted snacking (no more late night bargaining with the cookie jar!);
• can improve blood sugar control, lower blood pressure and cholesterol levels, and increase brain health; and 
• can support achieving a lower body weight long-term.

The cons of intermittent fasting 16:8:

• can increase hunger and the possibility of eating more than you need and making less health-promoting food choices;
• could make it harder for you to eat enough nutrients;
• can clash with your social, family, or work commitments; and
• may initially leave you feeling hungry, brain-foggy, and low on energy.

Which leads us to our million dollar question…

Is the intermittent fasting 16:8 method right for you?

Now you’ve got a grasp on how a 16:8 intermittent fasting plan works, how do you feel about trying it?

Yes, SIMPLE, I am in! 

If your brain is making “huh! This sounds kinda … cool!” noises at the thought of a 16:8 intermittent fasting protocol that:

• is the same every day, Mon-Sun
• lets you eat the food you want for 8 hours a day
• allows you to spend most of your fasting hours asleep
• gives you the flexibility to choose your own eating window
• means you don’t have to count calories 

then give 16:8 fasting a whirl. 

Choose the 8 hour window that feels right for you as a starting point, decide which day you’ll begin, and go for it! Or, to keep things even more SIMPLE, check out our SIMPLE quiz and we’ll walk you through the process. 

I’m not sure, SIMPLE … help me figure it out.

If intermittent fasting has caught your imagination but you’re wondering if another protocol would suit you better, we’ve got you. Let’s look at some other options. 

Intermittent fasting 16:8 vs 18:6 (and other time restricted eating windows).

Perhaps a shorter or longer fast sounds more you. If so, why not try one of these options:

• 12:12
• 14:10
• 15:9
• 18:6
• 20:4 

Which would fit your lifestyle best?

Intermittent fasting 16:8 vs 5:2 fasting

5:2 fasting means eating as you typically would five days a week and practicing a modified fast — where you reduce your intake to 500-600 calories — on the other two. 

5:2 arguably requires less effort vs 16:8 fasting as you’re not fasting every day, and the 5:2 structure may work better with your family, social, and work life. 

However, the fasting periods are longer and hunger could be a bigger issue. You also need to count calories on your fast days, which adds complexity. 

Intermittent fasting 16:8 vs alternate day fasting (ADF)

With ADF, you fast every other day and eat as you typically would on the days between. Again, you’re not fasting every day which might fit your lifestyle better. Though, again, the fast periods are longer and hunger can be a real challenge. 

Intermittent fasting 16:8 vs one meal a day (OMAD)

OMAD requires you to fast for 23 hours and eat all your nutrients in a one-hour window. You can schedule your eating window any time that works for you, but overall it’s very restrictive. 

Intermittent fasting 16:8 vs water fasting

A water fast — where you only consume water for 24-72 hours — is a short term option. It is quite restrictive, but may suit your goals.  

It’s your call whether the 16:8 intermittent fasting plan is right for you. If after all that you’re still side-eyeing the screen in a “I might like this, but I’m not sure” way, no worries. Our suggestion: just try it for a couple of days.

There are no binding decisions here. Simply have a look at our beginners guide for intermittent fasting schedules, dip a toe in the water and see if you like it.

Written by Trey Reck

Medically reviewed by Josie Porter, RD

Published on | Updated on March 28, 2024