Written by Kiel DiGiovanni | Co-founder
Fact checked by Andrew Lenau, ISSA CPT & Sports Nutritionist
FACT CHECKED
People looking to lose fat quickly have turned to all types of fad diets over the past few decades. From low fat to high fat to low carb to gluten free to 6 small meals a day to raw veggies without dressing.
Well, if you’ve tried any of these fad diets then you’ve probably come to a realization that either it was too difficult to be consistent with or the results weren’t worth the strict diet.
What's a simpler solution?
The solution could simply be skipping a meal or two each day or a few days a week.
Ever heard of intermittent fasting?
What is Intermittent Fasting?
This is fasting (abstaining from food and beverages) for an amount of time ranging from 14 to 36 hours. With intermittent fasting, you are given a "window" to eat.
So if you fast for 16 hours a day, you can eat for 8 hours...i.e. fasting from 6pm to 10am, and eating from 10:01am to 5:59pm. We go through more intermittent fasting window options in our 16/8 intermittent fasting 7 day meal plan, so be sure to check it out for more information.
And if you think fasting for 16 hours a day is too difficult, think about the fact that each of us “fasts” every day; it is just known to us as “sleep”. All you need to do is extend that period of time several more hours.
It's actually not difficult at all.
But, why would you even do this?
Benefits of Intermittent Fasting
Intermittent fasting is proven to positively change the function of cells, hormones, and genes, which allows you to burn fat better, keep insulin levels down, increase growth hormone, and it helps your cells initiate vital cellular repair processes.
Intermittent fasting is also good for heart health, brain health, reducing inflammation and oxidative stress. It can even reduce the chance of neurodegenerative diseases like Alzheimers, as well as cancers, and potentially increase your lifespan.
While there are tons of health benefits, most people love intermittent fasting as it is a great way to lose weight, feel better, and to improve body composition.
Our distant hunter gather ancestors had no choice but to fast each day as they searched for food. You can be sure none of them were fat. Intermittent fasting for periods of time is biological to our human evolution. We are meant to fast as humans.
What is the science behind intermittent fasting?
As far back as the 1930’s researchers found that by drastically reducing the number of calories consumed by mice lead to a longer healthier life. Since then the same studies with similar results have been performed on other animals such as monkeys, fruit flies and roundworms.
According to Mark Mattson, senior investigator for the National Institute on Aging, part of the US National Institutes of Health says that fasting has been shown to improve biomarkers of disease, reduce oxidative stress and preserve learning and memory functioning (source).
So, how do you do intermittent fasting?
Below are 6 types of intermittent fasting techniques and schedules you can try out! We've also provided links to books on each of the fasting diets. While they are not necessary to read, as we explain what you need to know about each below, they are definitely worth reading if you decide to do the diet.
6 INTERMITTENT FASTING METHODS
The six most common types of intermittent fasting all have the common goal of achieving the benefits of fasting with varying approaches. You should choose the method that fits your daily schedule and lifestyle. If you choose a method that isn’t in tune with your lifestyle, chances are you won’t last too long. So, pick one that you think best suits you then reap the benefits of fasting.
As in all diets, intermittent fasting isn’t right for everyone. Before making a drastic change in your daily nutrition routine please consult your doctor, especially those with existing health conditions. Please keep in mind that the intermittent fasting method should be in sync with your individual goals and daily lifestyle. In addition, men's and women's intermittent fasting needs and experiences may vary, so take this into consideration as well.
Please note that these methods used in conjunction with regular exercise will yield far superior results.
1. Eat Stop Eat by Brad Pilon
Method: Complete a 24-hour fast one or two times weekly.
Suited for: Already healthy eaters looking for an extra boost to break plateaus.
How to:
- Take a break from food for 24 hours once or twice per week.
- Choose start/end time that fits your schedule.
- Calorie-free drinks CAN be consumed during the fasting period.
Ex. If you finish lunch at 1pm on Monday, then you wouldn’t eat again until Tuesday at 1pm. There’s one of your 24 hour fasts for the week.
Why Eat Stop Eat?
- Reduce total calorie consumption.
- No restriction of certain foods.
Pros:
- Flexible program (1-2 times weekly).
- No forbidden foods.
- No counting calories, no weighing food *(Don’t go overboard it’s always about moderation).
Cons:
- Difficult for some to go 24 hours without food at the beginning (Start with a 16-hour fast build up to the 24-hour fast).
- Some people will experience side effects such as headaches, fatigue, or feeling cranky or anxious (Don’t worry these symptoms will diminish over time as your body adjusts).
- The extended period of fasting might lead to certain people to binge eat once the fast is completed.
Tip: Start the fast on a very busy day or days without eating obligations (business lunches, family gatherings etc.)
Buy the Eat Stop Eat book on Amazon
2. The Leangains Method A.K.A The 16/8 Method by Martin Berkhan
Method: Don’t eat after dinner, then skip breakfast the next day.
Suited for: Devoted gym-goers who want to build muscle and lose fat.
How to:
- Women = Fasting time 14 hours, feeding time 10 hours.
- Men = Fasting time 16 hours, feeding time 8 hours.
- Calorie-free drinks permitted during fast (coffee, diet beverages etc.).
- Start fast after dinner so sleeping takes up most of fasting time. (Break the fast about 6 hours after waking up).
Ex. If you finish your last meal at 8 pm on Monday and then don’t eat until 12 in the afternoon on Tuesday; you’ve completed your 16 hour fasting time.
Why Leangains?
- Most natural fasting time (you’ll be sleeping through the majority of the fasting time).
- Still able to eat 2-3 meals during feeding time.
Pros:
- Fits most people’s schedule (Most natural fasting time).
- Meal frequency is irrelevant (Eat any time during feeding period. Most people would eat 3 meals as this is ingrained in our brains).
Cons: Lean gains has strict guidelines of what to eat especially if you’re working out.
Tips:
- Try to keep fasting/feeding times constant for best results.
- Whole unprocessed foods should make up the bulk of your calorie intake.
Buy the Leangains Method book on Amazon
3. The Warrior Diet by Ori Hofmekler
Method: Under eat during the day; eat one huge meal at night. You can learn more about this in our article on 20/4 Fasting.
Suited for: The dedicated few who can follow rules.
How to:
- Fast for about 20 hours/day.
- Eat 1 large meal at night.
- Maximize the Sympathetic Nervous System’s “fight or flight” response by eating small servings of raw vegetables, fruits and protein during the 20 hour “fasting” time.
- Maximize the Parasympathetic Nervous System’s ability by overeating during the 4 hours of feeding time at night.
Ex.:
- Daytime under-eating 20 hours (eat small amount of raw fruits, veggies and protein).
- Nighttime overeating (4 hours) - Eat in this order: veggies, fats, proteins, carbs(only if you’re still hungry).
Why The Warrior Diet?
- Feeding the body the nutrients it needs in sync with circadian rhythms.
- Humans are nocturnal eaters programmed to eat at night.
Pros:
- Fasting period allows you to still eat small snacks.
- People have reported increased energy and fat loss.
Cons:
- What/when to eat guidelines can be tough to follow.
- Strict scheduling and meal plan makes it difficult to adhere to especially for social butterflies.
- Some people don’t like to eat large meals at night.
Tip: Food choices similar to the Paleo diet.
Buy The Warrior Diet book on Amazon
4. The Alternate-Day Diet by James Johnson, M.D.
Method: Fasting every other day. (Eat normal one day, next day extreme caloric deficit).
Suited for: Experienced dieters trying to hit a specific weight goal.
How to:
- Eat normal (Men:2500cal/day Women: 2000cal/day) -Eat VERY LITTLE (1/5th of normal caloric intake) the next day.
- Try to schedule intense workouts with the normal feeding days.
Ex. Monday eat normally throughout the day, then Tuesday eat 1/5th of what you ate on Monday.
Why Alternate Day Fasting?
- Fast way to cut fat.
- Can still eat (up to 500calories) during fasting period.
Pros:
- Mainly for achieving weight loss.
- According to UpDayDownDayDiet people who cut their calories 20-35% saw about a 2 ½ pound loss per week.
Cons: Those lacking self control tend to binge eat on their “normal” days.
Tip: Use meal replacement shakes on the “fasting” days in the beginning.
Buy The Alternate-Day Diet book on Amazon
5. The FastDiet by Michael Mosley
Method: 5 days/week eat normally; 2 days a week restrict calories to 500-600/day.
Suited for: Anyone looking to lose weight as it is easier to follow for beginners.
How to:
- Normal (5) days eat daily recommended calories (Men:2500cal/day Women:2000cal/day).
- 2 days caloric deficit spaced between normal eating days. (Men:600cal/day Women:500cal/day).
- Focus on eating nutritious, high protein, high fiber foods that will make you feel full.
Ex. Monday/Thursday fasting days. Rest of the week consume normal amount of calories.
Why FastDiet? People are more likely to stay consistent with this type of dieting long term. This diet will help to lose weight and improve metabolic condition.
Pros:
- Easy to follow for people with hectic daily schedules.
- Lose weight without long periods of fasting.
Cons: No clinical studies that show the Fastdiet itself.
Tip: Eat soup on your down days to help feel fuller.
6. Feast/Fast by John Romaniello
Method: 5 days normal eating; One cheat day; One day water fast (ends up being an approx. 36 hours fast).
Suited for: People who exercise regularly and like the concept of cheat days and cheat meals.
How to:
- Eat normal nutritious diet 5 days a week.
- Have one cheat day.
- Don’t eat from your last meal of your cheat day until the morning two days later.
Ex. Have your cheat day on Sunday and finish last meal at 10pm. Don’t eat anything on Monday, start eating your balanced diet on Tuesday morning.
Why Feast/Fast?
Dieting causes leptin levels to drop which in turn slows down fat loss. When you cheat (overeat), your leptin levels increase, thus speeding up the rate of fat loss. So, by scheduling a period of fasting subsequent to a cheat day does the following things:
- Prevents fat gain from the caloric overload of cheating by creating an immediate caloric deficit.
- Higher leptin levels from the cheat day prevent stagnated fat loss, which allows the hormonal benefits from the fast to continue unhindered.
Pros:
- People are able to stick with this method because they can look forward to the cheat day.
- Only one true day of fasting each week.
Cons: Some people might have trouble adhering to the 36 hour fasting period every week.
Tip: Eat all the foods (ice cream, wings, pizza, beer) you might crave throughout the week...EAT A LOT!
How to handle the hunger when intermittent fasting?
If this is your first foray into the world of fasting then you should be prepared to face some of the side effects such as hunger, sleepiness and overall weakness. However, these feelings will pass after your body gets used to the change in your diet routine. Try to keep busy to get your mind off of FOOD.
Those of you who are newbies to fasting might want to consider keeping some small snacks handy for your first few fasting days, just in case you feel faint or ill.
Intermittent fasting isn’t good for everyone, so if you are feeling faint or ill constantly after your first few fasting days please consult with your doctor before continuing any type of fasting.
People Who Shouldn’t Intermittent Fast:
- People who suffer or experienced eating disorders.
- Women who are attempting to conceive or have issues with fertility.
- Pregnant women, nursing mothers.
- Children and individuals who have Type 1 diabetes.
- People sensitive to drops in blood sugar levels.
- Individuals with known nutrient deficiencies as well as malnourished or underweight.
Women should consult a medical professional before starting any type of fasting due to:
- Fasting not as effective for women compared with men.
- Some women reported their menstrual periods stopped while fasting but returned once they went back to a traditional eating regiment.
What foods or beverages can you consume while fasting?
No foods should be eaten while fasting as it will break your fast. Some people will drink bone broth or curb their appetite with healthy fats like MCT oil, however this technically breaks your fast (but it won't take you out of ketosis, which is what you want for burning fat). So, if you want to do intermittent fasting correctly, don't eat anything. And unless you're dry fasting, in which you also avoid all liquids, there are only three things you should drink and that's water, coffee, and tea. Needless to say, the coffee and tea must be consumed plain, without added sugar, milk, or cream.
What not to eat after fasting?
After fasting, you do not want to break your fast with unhealthy foods. It defeats the purpose of fasting as it derails results. After a fast, you want to eat healthy foods. However, not all healthy foods are ideal for breaking a fast, as they can cause discomfort. You want to eat foods that are easily digestible, like protein, non-cruciferous vegetables (cruciferous vegetables, such as broccoli) are hard to digest, avocado, and bone broth. Avoid cruciferous vegetables, lactose, and of course processed foods. After your first meal, you can add some more hard to digest foods to your plate if you like.
How long should You Do intermittent fasting?
You could intermittent fast every day for the rest of your life if you wanted. You can also do it on specific days. A lot of people like to do intermittent fasting on the weekdays and then take the weekends off. It's completely up to you.
For best results, try one of the intermittent fasting methods we listed above for a month and see how it goes. This will give you enough time to see noticeable results.
How much weight can you lose in a month with intermittent fasting?
It depends on what foods you are eating when you are not fasting and if you are exercising. It also depends on if you are overweight or not. But on average, if you eat healthy foods during your windows of eating and you workout 3-5 times a week, someone who is overweight can lose 10-15 pounds safely in a month.
Conclusion
Now you have a few weapons in your fat loss arsenal. These methods can be used to achieve amazing results if done correctly and combined with regular exercise. We may not have the miracle get ripped quick pill but with a few simple changes to your diet and the frequency you eat, you can reap the benefits of fasting. If you’re looking to lose weight or improve your health through eating habits, look no further than intermittent fasting.
Related Content:
- OMAD Diet: Can You Build Muscle Eating Once Per Day?
- Learn How to Master Your Metabolism
- 3 Day Fast Guide: Before & After Results, Benefits & Tips
- Is it Possible to Lose 20LBS in a Month?
- Is Fasted Cardio Better for Fat Loss?
Kiel DiGiovanni
Author