04 Oct The Ultimate Beginner’s Guide to the 16:8 Diet (Plus Sample Weekly Schedule)
Today, I’ll give you a comprehensive overview of the 16:8 diet and how you can get started with it today.
What is the 16:8 diet?
16:8 intermittent fasting involves limiting consumption of foods and calorie-containing beverages to a set window of eight hours per day and abstaining from food for the remaining 16 hours.
This cycle can be repeated as frequently as you like — from just once or twice per week to every day, depending on your personal preference.
16:8 intermittent fasting has skyrocketed in popularity in recent years, especially among those looking to lose weight and burn fat.
While other diets often set strict rules and regulations, 16:8 intermittent fasting is easy to follow and can provide real results with minimal effort.
It’s generally considered less restrictive and more flexible than many other diet plans and can easily fit into just about any lifestyle.
In addition to enhancing weight loss, 16/8 intermittent fasting is also believed to improve blood sugar control, boost brain function and enhance longevity.
What other types of 16:8 diets are there?
Technically, there’s only one type of 16:8 diet.
But there are several different types of intermittent fasting, although the 16:8 method is typically the most common.
Those who partake in IF often describe their routine by breaking up 24 hours into when they are consuming food versus when they are not. For example, the number of hours fasted followed by the eating window hours.
So, 16:8 fasting means eating within a window of eight hours each day — such as from 12pm to 8pm — and not eating during the remaining 16 hours.
The windows can vary based on the individual. Someone might only eat within a six-hour window (18:6) or four-hour window (20:4).
So how does the 16:8 diet work?
There are lots of beneficial changes in your body due to 16:8 intermittent fasting — right down to the cellular level.
It causes insulin levels to drop, which improves insulin sensitivity, optimizes blood sugar levels and burns fat.
It can also increase levels of human growth hormone (HGH), an important hormone involved in cellular regeneration that has been linked to improvements in body composition and decreased body fat.
Plus, short-term fasting has been shown to induce autophagy, an important cellular repair process that helps remove waste and toxins to keep your body healthy.
Other research suggests that intermittent fasting may offer protection against chronic disease and brain aging by altering specific genes and molecules within your body.
Will the 16:8 diet help with ketosis?
We’re not really concerned about the keto diet here at the168diet.com, but many of those practicing intermittent fasting are.
The 16:8 diet can help you burn fat faster — which is crucial for ketosis.
The two are related for three reasons:
- For our bodies to get into ketosis, we must be fasting in some sense — either by not eating any food at all or by keeping carbs extremely low. When we’re in ketosis, it means the body is breaking down fat for energy.
- Since IF obviously involves fasting, it can help our bodies deplete glucose stores at a faster rate and speed up the process of running on fat.
- Many people who start a ketogenic diet will begin by fasting to help them enter ketosis more quickly.
Does the 16:8 diet actually work?
The first study investigating the effects of the 16:8 diet on humans was recently published in the journal Nutrition and Healthy Aging. During the 12-week trial, 23 obese adults practiced time-restricted eating from 10 a.m. to 6 p.m., eating whatever they wanted within the 8-hour period.
By the end, researchers found that participants ate around 350 calories less per day than the control group, lost a small amount of body weight, and also saw improvement in systolic blood pressure.
The findings suggest this form of time-restricted eating is effective for losing weight, although it may not be as effective as other forms of fasting, such as alternate day fasting, which creates an overall larger calorie deficit.
Researchers also noted that the consumption of caffeinated drinks during fasting hours may disturb your circadian rhythm, which affects metabolism.
“These findings suggest that 8-hour time restricted feeding produces mild caloric restriction and weight loss in obese adults, without intentional calorie counting,” the study authors wrote, emphasizing that while the results are promising, longer-term, larger-scale research around the 16:8 diet is still needed. Most other studies around intermittent fasting have used animals instead of human participants.
Fasting for 16 hours also forces your body to go into ketosis, meaning your body starts burning fat for energy and produces ketones in your urine (yep, just like the keto diet), which could contribute to weight loss.
Sample 16:8 diet schedule
Remember, you’re fasting for 16 hours and then only eating within a specific 8-hour window. For example, only eating from noon-8 PM, essentially skipping breakfast.
Some people only eat in a 6-hour window, or even a 4-hour window (the 18:6 diet and 20:4 diet, respectively). This is “feasting” and “fasting” parts of your days and the most common form of Intermittent Fasting.
Two examples: The top means you are skipping breakfast, the bottom means you are skipping dinner each day:
You can adjust this window to make it work for your life:
- If you start eating at: 7AM, stop eating and start fasting at 3pm
- If you start eating at: 11AM, stop eating and start fasting at 7pm
- If you start eating at: 2PM, stop eating and start fasting at 10pm
- If you start eating at: 6PM, stop eating and start fasting at 2am
The 4 major benefits of the 16:8 diet
Fat loss is great, but it isn’t the only benefit of fasting.
1. Intermittent fasting makes your day simpler.
I’m big on behavior change, simplicity, and reducing stress.
Intermittent fasting provides additional simplicity to my life that I really enjoy. When I wake up, I don’t worry about breakfast. I just grab a glass of black coffee and start my day.
However, intermittent fasting allows me to eat one less meal, which also means planning one less meal, cooking one less meal, and stressing about one less meal. It makes life a bit simpler and I like that.
2. Intermittent fasting helps you live longer.
Scientists have long known that restricting calories is a way of lengthening life. From a logical standpoint, this makes sense. When you’re starving, your body finds ways to extend your life.
There’s just one problem: who wants to starve themselves in the name of living longer?
The good news is that intermittent fasting activates many of the same mechanisms for extending life as calorie restriction. In other words, you get the benefits of a longer life without the hassle of starving.
3. Intermittent fasting may reduce the risk of cancer.
This one is up for debate because there hasn’t been a lot of research and experimentation done on the relationship between cancer and fasting. Early reports, however, look positive.
This study of 10 cancer patients suggests that the side effects of chemotherapy may be diminished by fasting before treatment. This finding is also supported by another study which used alternate day fasting with cancer patients and concluded that fasting before chemotherapy would result in better cure rates and fewer deaths.
Finally, this comprehensive analysis of many studies on fasting and disease has concluded that fasting appears to not only reduce the risk of cancer, but also cardiovascular disease.
4. Intermittent fasting is much easier than dieting.
The reason most diets fail isn’t because we switch to the wrong foods, it’s because we don’t actually follow the diet over the long term. It’s not a nutrition problem, it’s a behavior change problem.
This is where intermittent fasting shines because it’s remarkably easy to implement once you get over the idea that you need to eat all the time. For example, this study found that intermittent fasting was an effective strategy for weight loss in obese adults and concluded that “subjects quickly adapt” to an intermittent fasting routine.
The 16:8 diet tips & tricks to help you get started today
Getting started with 16:8 intermittent fasting is easy.
Stop wondering: “can I fast 15 hours instead of 16?” or “what if I eat an apple during my fasted period, will that ruin everything?” Relax.
Your body is a complex piece of machinery and learns to adapt. Everything is not as cut and dry as you think.
If you want to eat breakfast one day but not another, that’s okay. If you are going for optimal aesthetic or athletic performance, I can see the need to be more rigid in your discipline, but otherwise…freaking chill out and don’t stress over minutiae! Don’t let perfect be the enemy of good.
2. Take fasted walks in the morning.
I found these to be very helpful in reducing body fat, and also gave my day a great start to clear my mind and prepare for the day. Simply wake up and go for a mile walk.
3. Listen to your body during workouts.
If you get light headed, make sure you are consuming enough water. If you notice a significant drop in performance, make sure you are eating enough calories (especially fats and protein) during your feasting window.
And if you feel severely “off,” pause your workout. Give yourself permission to EASE into intermittent fasting and fasted workouts. This is especially true if you are an endurance athlete.
4. Expect funny looks if you spend a lot of mornings with breakfast eaters.
A few weeks back I had a number of friends staying with me, and they were all completely dumbfounded when I told them I didn’t eat breakfast anymore.
I tried to explain it to them but received a bunch of blank stares.
You will get weird looks from those around you…embrace it. I still go to brunch or sit with friends, I just drink black coffee and enjoy conversation.
6. Stay busy.
If you are just sitting around thinking about how hungry you are, you’ll be more likely to struggle with this. For that reason, I time my fasting periods for maximum efficiency and minimal discomfort:
My first few hours of fasting come after consuming a MONSTER meal, where the last thing I want to think about is eating.
When I’m sleeping: 8 of my 16 hours are occupied by sleeping. Tough to feel hungry when I’m dreaming about becoming a Jedi.
When I’m busy: After waking up, 12 hours of my fasting is already done. I spend three hours doing my best work (while drinking a cup of black coffee), and then comes my final hour of fasting: training.
7. Zero-calorie beverages (and black coffee or tea) are okay.
I drink green tea in the morning for my caffeine kick while writing. If you want to drink water, black coffee, or tea during your fasted period, that’s okay. Remember, don’t overthink it – keep things simple!
If you want to put milk in your coffee, or drink diet soda occasionally while fasting, I’m not going to stop you.
Remember, we’re going for consistency and habit-building here – if milk or cream in your coffee makes life worth living, don’t deprive yourself.
So, to summarize…
Getting started with the 16:8 diet doesn’t have to be hard.
- The point of the 16:8 diet is actually to eat fewer calories than your body needs on a daily basis–that’s how you lose weight
- Don’t get lost in the details of the fasted state–in that time, eat as little as possible in the start. A banana to begin is OK. Later, a cup of black coffee or black tea is fine, even if it has 2 calories per cup of black coffee. It’s better to have almost zero calories, rather than to not do anything at all.
- Keep at it. Don’t give up.
- For social cohesion, probably don’t tell anyone you’re doing it in the beginning. Wait until a few weeks in when people see significant changes in your appearance, and only then let them know that you’re simply skipping breakfast (or whatever meal you’re skipping).
- Still, people are weird. If you say you’re skipping breakfast, they’ll tell you that you’re killing yourself because everyone is addicted to breakfast.
- Again, keep at it, don’t give up. Even if you’ve eaten more than you should’ve–don’t worry. Pick yourself up the next day.