How to Do Intermittent Fasting: Diet Guide

How to Do Intermittent Fasting: Diet Guide


Intermittent fasting is the latest diet craze, but is it for you? No matter what your reason for trying this dieting method — weight loss, improving health or simplifying your lifestyle — it can have powerful effects on your body and brain. Even if abstaining from eating for extended periods of time sounds crazy to you, give it a chance! Read on and learn about all the benefits of skipping a meal now and then.

What is intermittent fasting?

Intermittent fasting is an eating pattern that cycles between periods of fasting and eating. In short, there aren’t any specific dieting rules other than deciding when to eat and when not to eat. Humans have been fasting for thousands of years, sometimes by choice, for religious reasons, and sometimes because there simply wasn’t food available. Human bodies are built to withstand periods of hunger, so it’s not unnatural to skip a meal here and there.

There’s quite a bit of evidence in favor of fasting, with studies showing that bodies change for the better when following this kind of eating plan. A study published in The Journal of Clinical Investigation found that fasting enhances growth hormone secretion. Growth hormones are important regulators of growth, metabolism and body structure.

Fasting also leads to significant reductions in blood sugar and insulin levels, which are both important factors in determining the development of chronic diseases, like diabetes. Studies in rodents found that fasting can extend lifespan and affect brain aging. Finally, fasting has been found to be an effective method for losing weight, and weight loss significantly affects risk of chronic health issues, like heart disease.

So, how do you start reaping the benefits of this diet? There are a few methods of fasting that you can try, but the two most popular methods will be discussed here. First, the 16/8 method: a.k.a. fasting for 16 hours each day.

Under the 16/8 method, you restrict your daily “eating window” to 8-10 hours. You can eat two to three meals within that time. A typical eating window schedule ranges from noon to 8 p.m. and skip breakfast in the morning. During a fast, you can drink water, coffee and other non-caloric beverages to reduce hunger levels. As the name suggests, you’ll be fasting for 16 hours, but if you’re sleeping eight hours each night, you’ll only be awake and fasting for about eight hours during the day.

The 5:2 diet involves a 24-hour fast twice a week. On fast days, you stop eating from dinnertime the previous day and refrain from eating for a full day. You resume eating at breakfast the following day. Like the 16/8 fast, non-caloric beverages are allowed during your fast day. On an “eat day” you can eat a full slate of healthy meals. It’s important that you don’t fast for more than a day so your body can get its proper nutrients on eat days. This method is a bit more difficult than the 16/8 method, but some practitioners can fast for as many as three days a week, a.k.a. alternate day fasting.

Are you curious about trying any of these methods? Explore some of the benefits of fasting below and see if you walk away convinced and motivated to start.

Pros of Intermittent Fasting

  • Easy to start. There are no cookbooks, guides, measurements or any other precursors to start this diet. It’s as simple as refraining from eating.
  • Add-ons. This eating plan works well with pretty much any other diet you’ve been meaning to try. Your best bet is a balanced diet with plenty of fruits and veggies.
  • Multiple health benefits. Some studies suggest that fasting every other day showed many positive effects, such as stress resistance, increased insulin sensitivity, reduced morbidity and increased life span.
  • Resting your digestive system. Taking a break from eating frees up 65 percent of your body’s energy consumption to do other things, like concentrate better. Although you may feel some sluggishness on your first few fast days, this tends to pass in time.
  • Weight loss. It’s a simple, well-known fact that eating less leads to weight loss. Fasting creates a caloric deficit that can lead to real results on the scale. As long as binge eating doesn’t occur on eat days, fasting can help those seeking to shed a few pounds.
  • Quick and beneficial changes. A study looked at how a diet similar to fasting affected a number of health markers. After just three months, the participants lost 5.7 pounds on average, had lower levels of insulin, lower markers of inflammation, lower Body Mass Index (BMI), less trunk fat, smaller waist circumference, lower blood pressure and less cholesterol.
  • Reducing risk factors for disease. A study in the journal Cell Metabolism showed intermittent fasting may decrease risk factors for diabetes, cardiovascular disease and cancer.
  • Community. There are several online communities on Facebook and elsewhere that help promote intermittent fasting and can guide you on your journey.

As mentioned earlier, there are numerous health benefits to fasting. If beginning a fast sounds unpleasant, you may reconsider when you hear some of the reasons in favor of skipping lunch.

Cons of Intermittent Fasting

There’s no way around it: starting regular fasting is hard. It’s not for everyone either, especially if you have certain health conditions or predispositions. Explore some of the reasons why fasting may not be the best choice.

  • Difficult hunger pangs. Depending on your body and needs, it may be more difficult to get past the initial hurdle of hunger and make this into a consistent habit.
  • Not great for pregnant or nursing women. Women who are pregnant or nursing should not attempt to fast, as their bodies are under increased caloric and physical demands.
  • Not great for the sick. As with any change in diet, you should consult your doctor to see if fasting is right for you. Fasting can interfere with various medical conditions, such as kidney and liver diseases.
  • Affects disordered eating. Fasting is not recommended for those with a history of eating disorders. Extended fasting can lead to dangerous complications and health problems.
  • Not too different from other calorie-cutting plans. A study found that of 100 overweight people assigned to one of three eating plans, those assigned a calorie-cutting diet and those who fasted fared about the same when it came to weight loss.
  • High dropout rate. The same study found that 38 percent of those assigned to the fasting regimen gave up on the diet.

How to Do Intermittent Fasting

Getting Started

While getting started on a fasting diet is simple enough, it definitely isn’t easy. Begin by setting a small goal of fasting through one meal, like breakfast. The 16/8 method might be better for those just starting out. If you prefer fasting on the 5:2 method, start by fasting through breakfast and lunch one day, then slowly moving on to fasting through dinner. Make sure to go at your own pace and no faster than that. Listen to your body!

If all of that seems too difficult, give a liquid, fruit or mono fast a try. By fasting on smoothies or small bowls of rice, you’ll get many of the benefits of fasting without having to fully commit. You may also want to change up your diet before undertaking fasting — transitioning from light, plant-based meals to fasting is much easier than if you’re eating carb-heavy meals.

How to Stay Motivated

Unlike many diets, fasting takes a bit of extra effort. How do you stay motivated when you’re feeling those hunger pangs? It may be good to find a fasting buddy or an online community so you can talk about your struggles. You may also want to write down your motivations for fasting and read them aloud once each day. Taking photos of your changing body may also keep you determined. An app like My Fitness Pal keeps track of your weight, caloric intake, progress photos and more.

Set short-term goals and take it easy if you make a mistake. Your health won’t be built in a day. It’s the result of a collection of small choices you make over a period of time.

Preparing for Fasting

There’s not much prep work in a fasting diet, but you want to make sure talk to your doctor before starting any fasting regimens. Also, remember to eat a whole day’s worth of meals before you set out on any fast. It’s easier and healthier to fast when you’ve gotten all your nutrients the day before. Focus on eating veggies and protein to stay feeling full for longer.

If you want to be extra prepared before fasting, alter your diet one to two weeks before starting your new regimen. Reduce your intake of refined sugars and processed foods, and switch to a healthy diet full of fresh foods. You may also want to reduce your caloric intake and get some moderate amounts of exercise.

A Day in the Life of an Intermittent Fasting Follower

While you can practice any kind of diet while practicing intermittent fasting, let’s focus on healthy, protein-rich and plant-based meals for breaking your fast. Here’s what a regular day on a 16/8 fast method looks like.

Breakfast: Skip this meal and don’t eat anything until lunchtime. You can have non-caloric drinks like coffee (and if you really need it, a non-caloric sweetener like Splenda).

Lunch: Creamy avocado and white bean wraps


  • 2 tablespoons cider vinegar
  • 1 tablespoon canola oil
  • 2 teaspoons finely chopped, canned chipotle chile in adobo sauce
  • ¼ teaspoon salt
  • 2 cups shredded red cabbage
  • 1 medium shredded carrot
  • ¼ cup chopped, fresh cilantro
  • A 15-ounce can of rinsed white beans
  • 1 ripe avocado
  • ½ cup shredded sharp cheddar cheese
  • 2 tablespoons minced red onion
  • 8- to 10-inch whole-wheat wraps or tortillas (4)

Cooking Instructions

  1. Whisk the vinegar, oil, chipotle chile and salt in a medium bowl. Add cabbage, carrot and cilantro. Toss it together to combine.
  2. Mash the beans and avocado in another medium bowl with a potato masher or fork. Stir in the cheese and onion.
  3. Assemble the wraps by spreading about ½ cup of the bean-avocado mixture onto a wrap (or tortilla) and top it with about ⅔ cup of the cabbage-carrot slaw. Roll up. Repeat with remaining ingredients. Cut the wraps in half to serve, if desired.

Dinner: Roast chicken and sweet potatoes


  • 2 tablespoons whole-grain or Dijon mustard
  • 2 tablespoons chopped, fresh thyme or 2 teaspoons dried
  • 2 tablespoons extra virgin olive oil, divided
  • ½ teaspoon salt, divided
  • ½ teaspoon freshly ground pepper, divided
  • 1½ to 2 pounds of bone-in chicken thighs, skin removed
  • 2 medium sweet potatoes, peeled and cut into one-inch pieces
  • 1 large red onion, cut into one-inch wedges

Cooking Instructions

  1. Position the rack in the lower third of the oven and preheat to 450 degrees Fahrenheit. Place a large-rimmed baking sheet in the oven to preheat.
  2. Combine mustard, thyme, one tablespoon of oil and ¼ teaspoon each of salt and pepper in a small bowl. Spread the mixture evenly on the chicken.
  3. Toss the sweet potatoes and onion in a bowl with the remaining one tablespoon of oil and ¼ teaspoon each of salt and pepper. Carefully remove the baking sheet from the oven and spread the vegetables on it. Place the chicken on top of the vegetables.
  4. Return the pan to the oven and roast, stirring the vegetables once halfway through, until the vegetables are tender and beginning to brown. Insert an instant-read thermometer into a chicken thigh and make sure it registers 165 degrees Fahrenheit. This should take 30 to 35 minutes.

Snack Suggestions: Hard-boiled eggs, cucumber sushi, avocado hummus, bell pepper oven fries, cool ranch crisps, apple chips, trail mix bites, froyo fruit bites, melon prosciutto skewers or pickle rollups.

Drink Suggestions: Water, coffee, tea, La Croix, red wine, fruit and veggie smoothies and anything without added sugars or too many calories.

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