Intermittent fasting (IF) is growing by leaps and bounds mainly because it is manageable for long-term results and it forces you to eat in direct opposition to traditional diet rules, and that—along with the results—it what’s generating all the buzz.
There are good number of science-backed medical benefits to intermittent fasting (IF). First off, studies have shown that IF makes us less insulin resistant. And several studies suggest that people who fast have more energy, better cognition and memory, and increased production of something called neurotrophic growth factor (a protein that promotes neuron growth and protection).
Fasting intermittently can also prime your cells so they can better handle stressful insults. One study says that a break from eating jolts cells into a minor stressful state, making them more capable of later fending off other types of stress (like the type that can lead to disease.) Lastly, studies among people who participate in Ramadan – a month-long religious fast – say IF may improve immunity, lower diabetes risk, and improve heart health.
In fact, lots of studies on lots of different groups show some cardiovascular, cognitive, diabetes and weight loss benefits on IF. Their major limitation is they tended to be small, short-term studies. Despite that, many in the field are excited about IF’s possibilities.
Five Methods for Different Lifestyles
The five different methods of intermittent fasting will yield better results for different people. Choose a method that makes your life easier to ensure that your effort is sustainable and the payoff for your fasting is long-lived.
So what’s the first step in getting started? Each method has its own guidelines for how long to fast and what to eat during the “feeding” phase. Below, you’ll find the five most popular methods and the basics of how they work. Keep in mind, intermittent fasting isn’t for everyone. Those with health conditions of any kind should check with their doctor before changing up their usual routine. Note that personal goals and lifestyle are key factors to consider when choosing a fasting method.
IF Method #1: Leangains
Best for: Dedicated gym-goers who want to lose body fat and build muscle.
How It Works: Fast for 14 (women) to 16 (men) hours each day, and then “feed” for the remaining eight to 10 hours. During the fasting period, you consume no calories. However, black coffee, calorie-free sweeteners, diet soda and sugar-free gum are permitted. (A splash of milk in your coffee won’t hurt, either.) Most practitioners will find it easiest to fast through the night and into the morning. They usually break the fast roughly six hours after waking up. This schedule is adaptable to any person’s lifestyle, but maintaining a consistent feeding window time is important. Otherwise, hormones in the body can get thrown out of whack and make sticking to the program harder.
What and when you eat during the feeding window also depends on when you work out. On days you exercise, carbs are more important than fat. On rest days, fat intake should be higher. Protein consumption should be fairly high every day, though it will vary based on goals, gender, age, body fat and activity levels. Regardless of your specific program, whole, unprocessed foods should make up the majority of your calorie intake. However, when there isn’t time for a meal, a protein shake or meal replacement bar is acceptable (in moderation).
Pros: For many, the highlight of this program is that on most days, meal frequency is irrelevant. You can really eat whenever you want to within the eight-hour “feeding” period. That said, most people find breaking it up into three meals easier to stick to (since we’re typically already programmed to eat this way).
Cons: Even though there is flexibility in when you eat, Leangains has pretty specific guidelines for what to eat, especially in relation to when you’re working out. The strict nutrition plan and scheduling meals perfectly around workouts can make the program a bit tougher to adhere to.
IF Method #2: Eat Stop Eat
Best for: Healthy eaters looking for an extra boost.
How It Works: Fast for 24 hours once or twice per week. During the 24 hour fast, no food is consumed, but you can drink calorie-free beverages. After the fast is over, you then go back to eating normally — some people need to finish the fast at a normal mealtime with a big meal, while others are OK ending the fast with an afternoon snack. Time it however works best for you, and adjust your timing as your schedule changes.
The main rationale? Eating this way will reduce overall calorie intake without really limiting what you’re able to eat — just how often, according to Eat Stop Eat. It’s important to note that incorporating regular workouts, particularly resistance training, is key to succeeding on this plan if weight loss or improved body composition are goals.
Pros: While 24 hours may seem like a long time to go without food, the good news is that this program is flexible. You don’t have to go all-or-nothing at the beginning. Go as long as you can without food the first day and gradually increase fasting phase over time to help your body adjust. For example, start the fast when you are busy, and on a day where you have no eating obligations (like a work lunch or happy hour).
Another perk? There are no “forbidden foods,” and no counting calories, weighing food or restricting your diet, which makes it a bit easier to follow. That said, this isn’t a free-for-all — you still have to eat like a grown-up. It’s all about moderation: You can still eat whatever you want, but maybe not as much of it.
Cons: Going 24 hours without any calories may be too difficult for some — especially at first. Many people struggle with going extended periods of time with no food, citing annoying symptoms including headaches, fatigue, or feeling cranky or anxious (though these side effects can dimish over time). The long fasting period can also make it more tempting to binge after a fast. This can be easily fixed… but it takes a lot of self-control, which some people lack.
IF Method #3: The Warrior Diet
Best for: People who like following rules. The devoted.
How It Works: Warriors-in-training can expect to fast for about 20 hours every day and eat one large meal every night. What you eat and when you eat it within that large meal is also key to this method. The philosophy here is based on feeding the body the nutrients it needs in sync with circadian rhythms and that our species are “nocturnal eaters, inherently programmed for night eating.”
The fasting phase of The Warrior Diet is really more about “undereating.” During the 20-hour fast, you can eat a few servings of raw fruit or veggies, fresh juice, and a few servings of protein, if desired. This is supposed to maximize the Sympathetic Nervous System’s “fight or flight” response, which is intended to promote alertness, boost energy, and stimulate fat burning.
The four-hour eating window — known as the “overeating” phase — is at night in order to maximize the Parasympathetic Nervous System’s ability to help the body recuperate, promoting calm, relaxation and digestion, while also allowing the body to use the nutrients consumed for repair and growth. Eating at night may also help the body produce hormones and burn fat during the day. During these four hours, the order in which you eat specific food groups matters, too. For example, start with veggies, protein and fat. After finishing those groups, only if you are still hungry should you tack on some carbohydrates.
Pros: Many have gravitated toward this diet because the “fasting” period still allows you to eat a few small snacks, which can make it easier to get through. With this IF method, many practitioners report increased energy levels and fat loss.
Cons: Even though it’s nice to eat a few snacks rather than go without any food for 20-plus hours, the guidelines for what you need to eat (and when) can be hard to follow long-term. The strict schedule and meal plan may also interfere with social gatherings. Additionally, eating one main meal at night — while following strict guidelines of what to eat, and in what order — can be tough. It’s especially hard for those who prefer not to eat large meals late in the day.
IF Method #4: Fat Loss Forever
Best for: Gym rats who love cheat days.
How It Works: Not completely satisfied with the IF diets listed above? This method takes the best parts of Eat Stop Eat, The Warrior Diet and Leangains, and combines it all into one plan. You also get one cheat day each week (yay!) — followed by a 36-hour fast (which may be not-so-yay for some). After that, the remainder of the seven-day cycle is split up between the different fasting protocols.
Many practitioners suggest saving the longest fasts for your busiest days, allowing you to focus on being productive. The plan also includes training programs (using bodyweight and free weights) to help participants reach maximum fat loss in the simplest way possible.
Pros: While everyone is technically fasting every day — during the hours when we’re not eating — most of us do so haphazardly, which makes it harder to reap the rewards. Fat Loss Forever offers a seven-day schedule for fasting so that the body can get used to this structured timetable and reap the most benefit from the fasting periods. (Plus, you get a full cheat day. And who doesn’t love that?)
Cons: On the flip side, if you have a hard time handling cheat days the healthy way, this method might not be for you. Additionally, because the plan is pretty specific and the fasting/feeding schedule varies from day to day, this method can be a bit confusing to follow.
IF Method #5: Alternate Day Fasting
Best for: Disciplined dieters with a specific goal weight.
How It Works: This one’s easy: Eat very little one day, and eat like normal the next. On the low-calorie days, that means one fifth of your normal calorie intake. Using 2,000 or 2,500 calories (for women and men, respectively) as a guide, “fasting” (or “down”) day should be 400 to 500 calories. Followers can use this tool to figure out how many calories to consume on “low-calorie” days.
To make “down” days easier to stick to, practitioners recommend opting for meal replacement shakes. They’re fortified with essential nutrients and you can sip them throughout the day rather than split into small meals. However, meal replacement shakes should only be used during the first two weeks of the diet — after that, you should start eating real food on “down” days. The next day, eat like normal. Rinse and repeat!
Pros: This method is all about weight loss, so if that’s your main goal, this is one to take a closer look at. On average, those who cut calories by 20 to 35 percent see a loss of about two and a half pounds per week.
Cons: While the method is pretty easy to follow, it can be easy to binge on the “normal” day. The best way to stay on track is planning your meals ahead of time as often as possible. Then you’re not caught at the drive-through or all-you-can-eat buffet with a grumbling belly.
5 Tips for Starting Your First Fast
If you do give fasting a try, keep these general tips in mind:
- Drink plenty of water. Staying well hydrated will make the fasting periods much easier to get through.
- Fast overnight. Throw yourself a bone and aim to fast through the night. That way, you’re (hopefully) sleeping during at least eight of those hours.
- Rewire your thought process. Think of fasting as taking a break from eating, not as a period of deprivation. It can be a way to break up the monotony of worrying about what you need to eat next and when. This is the mindset that will allow you do follow a fasting plan long-term, he says.
- Overcommit. It may seem counterintuitive, but the best plan is often to start when you’re busy — not on a day when you’ll be sitting on the couch wanting to snack.
- Hit the gym. Pairing intermittent fasting with consistent exercise will help you get better results. It doesn’t have to be hardcore or crazy — it can be something as simple as a full-body strength training routine two or three times per week.
- Learn the basics. Getting the basics down before starting one of the five IF methods will boost your chances of long-term success. There is a little-known plan called the 2 Week Diet that actually teaches you what to eat and when while keeping your metabolism at its optimal level. When your metabolism performs, you can shed weight and shed it FAST. Those on the diet report losing 12-23 pounds and 2-4 inches in a matter of 2 weeks – all backed by science. Watch this video to learn more about how the 2-week diet works.