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How to Start Intermittent Fasting | Everything You Need to Know

How to Start Intermittent Fasting | Everything You Need to Know


  • How to Start Intermittent Fasting
  • What Are the Different Types of Intermittent Fasting?
  • What Is the Best Way to Start Intermittent Fasting?
  • Can You Drink Water When Intermittent Fasting?
  • Can You Drink Coffee While Intermittent Fasting?
  • How to Be Successful with Intermittent Fasting
  • Is Fasting the Best Way to Lose Weight?
  • So you want to start intermittent fasting.

    I.F. is more than a dieting fad and has gained serious popularity in recent years due to its profound effects on weight loss and body composition. Fasting has also risen to fame because of its endorsement from the science community, where respected and successful researchers tout its health benefits on the heart, brain and virtually every other organ.  

    Before taking the plunge, it’s important to understand exactly what I.F. means. In simplest terms, intermittent fasting is a dietary schedule that involves eating only during specific time periods and not eating outside of what is commonly known as the “feeding window.”

    Most people get hung up on the idea of I.F. because it seems too difficult. Don’t be like most people. Intermittent fasting is not too difficult if you treat the program as a fun dietary investigation, rather than a chore you must undertake to become healthy. No one needs to do intermittent fasting, but it can be a powerful weight-loss tool if implemented properly.

    Yes, you’re (most likely) going to get ravenously hungry at some point, especially if you’re used to eating breakfast and small meals every 2-3 hours like you were instructed to do your entire life unto this point.

    Yes, you’re probably going to experience dips, dives and drops in your energy, focus and stamina. But if you stick with it, you may also experience improved fat-burning1, lowered blood sugar levels and improved insulin sensitivity2, improved heart health2 and a whole host of other benefits of intermittent fasting.

    How to Start Intermittent Fasting

    Before you get started, check these few things off your to-do list:

    • Ask your doctor if intermittent fasting is ok for you. While most people are good to give I.F. a go, some people shouldn’t. Those groups include people with medical conditions like heart disease and Type 1 diabetes, women who are pregnant or lactating, people with a history of disordered eating, people who are chronically stressed, and people who have never experimented with any type of calorie restriction. Additionally, some people who are highly active might find that intermittent fasting interferes with their athletic performance4.
    • Take a second look at your schedule. Does your work/school/life schedule allow you to easily implement intermittent fasting? If you regularly meet with colleagues for dinner and breakfast, it might be hard to establish a consistent feeding window.
    • Mentally prepare yourself. If you’re a beginner to intermittent fasting, know that you probably won’t get it perfect the first (or first few) times around. Practice self-forgiveness now, before any slip-ups cause you debilitating self-guilt.

    What Are the Different Types of Intermittent Fasting?

    There are several protocols for intermittent fasting, each with its own group of evangelists.

    The 16:8 Method

    One of the most popular is the 16:8 method, in which followers eat all of their food in an 8-hour window and fast for the remaining 16 hours of the day. This is often the easiest protocol for beginners to follow because for 7-8 of those 16 fasting hours, you should be asleep.

    The 5:2 Fasting Method

    Another popular I.F. protocol is the 5:2 diet, which involves eating normally on five days of the week and restricting calorie intake to only 500-600 calories on the other two days. Many people who follow the 5:2 diet fast on Mondays and Thursdays to split up the week relatively evenly.

    The Eat-Stop-Eat Diet

    The aptly named eat-stop-eat method is an I.F. protocol that involves a complete 24-hour fast once or twice a week. A common way to follow eat-stop-eat is to fast from one dinner to the next. For example, if you finish dinner at 6:30 p.m. on Wednesday, don’t eat again until 6:30 p.m. on Thursday.

    Alternate-Day Fasting

    Alternate-day fasting is an I.F. method in which followers eat normally one day, fast the next, and so forth. Fasting in this case often means eating only 500-600 calories on the fasting day, rather than complete caloric restriction.

    The Warrior Diet

    Ori Hofmekler, a former member of the Israeli Special Forces who transitioned his career to nutrition, popularized the Warrior Diet: a form of intermittent fasting that involves fasting throughout the day and seriously feasting during a 4-hour window at night.

    What Is the Best Way to Start Intermittent Fasting?

    Ah, the golden question. Just like anything else in health and fitness, there’s no one best way to start intermittent fasting. Really: You’re just going to have to give it a try. But to set yourself up for a successful first fast, follow these steps:

    1. Establish your feeding cutoff. The best way to do this is to consider what time you normally eat dinner. If you eat your last big meal at 6 p.m., start your fast at 6:30 p.m. You might gawk at that statement if you’re used to lounging on the couch with popcorn or whatever your evening kryptonite is. But ask yourself if you are really hungry an hour or two after dinner, or if you’re just eating out of habit.
    2. Consider what time you wake up. If you wake up at 6:30 a.m., congrats! You can easily complete a 12-hour fast.
    3. Think about when you normally eat breakfast. Do you tend to rush out the door shoving a granola bar in your mouth? If so, ask yourself what the point is. Again, discern whether you’re really hungry or if you’re shoveling breakfast because you’ve been told it’s the right thing to do since preschool. Instead, try waiting until 10 a.m. or so to eat a light snack.

    From there, begin adjusting your feeding window to one that works for you. For simplicity’s sake, use the 16:8 protocol as an example. Eating from 10 a.m. to 6 p.m. may very well work for you, if you work typical 9-5 hours. The best way to start intermittent fasting is to establish a feeding window that works with the rest of your life, not against it.

    Experiment with different types of intermittent fasting to find out what works best for your lifestyle. Many people consider the 16:8 protocol the simplest and most sustainable form of intermittent fasting. Begin with the 16:8 method and move on to more complicated protocols as you begin to feel more comfortable with the idea of fasting and your body adapts.

    It may take a week to 10 days to adjust to this new eating pattern. At first, you’ll likely feel hungry in the morning because the hormone ghrelin, which regulates your hunger patterns, makes your body crave food at the same time each day. After a while, your body will adapt to its new pattern.

    Can You Drink Water When Intermittent Fasting?

    Yes. In fact, you’re encouraged to drink more water than usual when intermittent fasting, especially during the fasting periods. Drinking water helps to suppress cravings and appetite during fasting periods, and is particularly helpful for beginners.

    Pro tip: Drink extra water while fasting to compensate for the hydration that you typically get from food. Add a teaspoon of pink Himalayan salt to every liter of water to help mitigate flushing and replenish mineral levels.

    Drinking extra water is also critical because you’ll likely be eating less food than usual, and up to 20 percent of your daily water intake comes from the food you eat. So if you’re intermittent fasting and haven’t upped your water intake, take a few swigs before you blame brain fog or fatigue on the fasting protocol.

    Can You Drink Coffee While Intermittent Fasting?

    Another profound yes! Coffee is allowed during both fasting and feasting periods of intermittent fasting protocols. But note that during your fasting periods, you can’t add sugar or any form of milk or creamer. Alternative zero-calorie sweeteners like Stevia are ok, but they may contribute to cravings during fasting periods.

    While you can drink coffee during intermittent fasting, try to avoid becoming dependent on it as a way to fend off cravings or bouts of fatigue. Instead, assess what and when you ate the day before to see if any tweaks might help. You can also drink unsweetened teas and zero-calorie beverages like Powerade Zero or Vitamin Water Zero, but be warned that palatable flavors might intensify cravings.

    How to Be Successful with Intermittent Fasting

    Many people don’t find success with intermittent fasting because they use their feeding periods as opportunities to eat whatever they want. And while you might feel like you’ve earned some junk food after fasting for 16, 24, or more hours, the effects of that on your weight-loss goals will outlast the dopamine blast from tasty food.

    Successful components of an I.F. protocol include:

    1. Calories: If you’re trying to lose weight, you still need to maintain a caloric deficit. Try not to compensate (consciously or otherwise) for missed calories during your feeding windows.
    2. Food quality: Just because you’re restricting your eating window, doesn’t mean you have free reign with food choices. Whole, nutrient-dense foods will always produce the best results.
    3. Consistency: Intermittent fasting isn’t a get-skinny-quick scheme. As with any healthy, sustainable weight-loss method, fasting requires dedication.
    4. Self-honesty: Don’t expect fasting to be easy at first. You’ve probably spent the majority of your life eating right when you’re hungry or whenever you feel like it. Fasting doesn’t allow you to do this, so don’t get disappointed when you feel like eating the entire fridge on your first day.

    Is Fasting the Best Way to Lose Weight?

    The benefits of fasting are astounding. Intermittent fasting reduces insulin resistance, protects against some chronic and degenerative diseases3, can improve heart health and makes healthy eating easier for some people. But there are mixed reviews about its impact on weight loss.

    Some research says fasting doesn’t produce significantly more weight loss than daily calorie restriction or even better adherence to the eating plan.

    However, some research points to hormonal changes produce by fasting that result in drastic weight loss. Fasting consistently and regularly lowers insulin levels and raises both growth hormone4 and norepinephrine5 levels. Because of those hormonal changes, fasting can increase your metabolic rate6.

    Consistent fasting also helps your body become more fat-adapted, which means you become more efficient at burning body fat for fuel, rather than the food you recently ate. This is often called flipping the metabolic switch.

    Intermittent fasting can be a helpful tool for weight loss if done properly. A 2014 review study found that intermittent fasting can cause up to 8 percent weight loss over 3-24 weeks.  That same study also found that people on I.F. protocols lost 4-7 percent of their waist circumference, which is one indicator that fasting comes with more health benefits than weight loss. If not done properly — for example, overeating during feeding periods —  I.F. won’t lead to weight loss any better than another method.

    Fasting can also make healthy eating easier, simply because you have fewer decisions to make and less time to make bad ones. Planning, preparing and cleaning up after 2-3 meals per day is much easier than doing all of that for 4-6 meals.

    The biggest caveat about intermittent fasting, though, is that it can interfere with business and social relations in an inconvenient way. You’re more likely to be successful with fasting if you’re single, don’t have a family, and don’t work in a client-facing business. Because eating is an ingrained social activity, you will more than likely face awkward situations wherein you must refuse food7 because of your fasting protocol.

    Next Steps

    At the end of the day, just like any weight-loss method, intermittent fasting works for some and doesn’t work for others. If you like the idea of I.F. and you don’t fall under any category of people who shouldn’t try intermittent fasting, then give it a go. If you don’t like the idea of I.F., then you can safely forego the advice in this article and continue eating in a way that works for you.

    Citations and Sources

    Heilbronn L, Smith S, Martin C, Anton S, Ravussin E. Alternate-day fasting in nonobese subjects: effects on body weight, body composition, and energy metabolism. Am J Clin Nutr. 2005;81(1):69-73. [PubMed]
    Varady K, Bhutani S, Church E, Klempel M. Short-term modified alternate-day fasting: a novel dietary strategy for weight loss and cardioprotection in obese adults. Am J Clin Nutr. 2009;90(5):1138-1143. [PubMed]
    Martin B, Mattson M, Maudsley S. Caloric restriction and intermittent fasting: Two potential diets for successful brain aging. Ageing Res Rev. 2006;5(3):332-353. [PMC]
    Ho K, Veldhuis J, Johnson M, et al. Fasting enhances growth hormone secretion and amplifies the complex rhythms of growth hormone secretion in man. J Clin Invest. 1988;81(4):968-975. [PMC]
    Zauner C, Schneeweiss B, Kranz A, et al. Resting energy expenditure in short-term starvation is increased as a result of an increase in serum norepinephrine. Am J Clin Nutr. 2000;71(6):1511-1515. [PubMed]
    Mansell P, Fellows I, Macdonald I. Enhanced thermogenic response to epinephrine after 48-h starvation in humans. Am J Physiol. 1990;258(1 Pt 2):R87-93. [PubMed]
    Collier R. Intermittent fasting: the next big weight loss fad. CMAJ. 2013;185(8):E321-E322. [PMC]
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