Does Intermittent Fasting Work?

Marcela Otero
Mar 23, 2017

“Breakfast is the most important meal of the day.” This platitude has been hammered into us from childhood, by doctors, grandmas, school nurses, weight loss professionals, and Tony the Tiger. A healthy, balanced breakfast is said to jumpstart your metabolism, give you energy and help you to focus, or so we’ve been told. But what if it simply weren’t true?

For adults, skipping breakfast as part of an intermittent fasting (IF) regimen can provide more benefits than eating first thing in the morning. Periodic fasting has been linked to weight loss, reduced inflammation, stimulated Human Growth Hormone (HGH) levels, and an increased lifespan. The data on this should be taken with a grain of salt, though, as most of the relevant studies have been performed on mice and fruit flies rather than humans.

Religious orders have long promoted fasting as a spiritual practice, but in the early 1900s, doctors began recommending it as part of treatment programs for diabetes, epilepsy and obesity. It really took off in 1945, when a study at the University of Chicago discovered that the benefits gleaned from intermittent fasting were just as effective in regards to life extension as those induced by calorie restriction —in rats, of course. In 2003, Mark Mattson concluded that fasting mice were less at risk for developing degenerative brain diseases and diabetes.

What does IF really mean? How do I do intermittent fasting?

There are many different ways to incorporate fasting into your life. If you think about it, everyone engages in a daily fast when they’re asleep. IF just means extending that period, and developing a more mindful attitude towards food. Culturally, the U.S. displays very little patience when it comes to food consumption. Snacks, processed food and over-indulgence have become a way of life, as well as a flaunting of wealth. Regardless of intent, it’s been showing increasingly in our collective waistlines for the past thirty years. Let’s review four of the most popular methods.

  1. Daily Intermittent Fasting - Popularized by Martin Berkhan of Leangains.com for gym-goers looking to build muscle and lose fat, this involves fasting for a period between 14 and 16 hours, and only eating during an eight to ten hour window of time. For many people, this means skipping breakfast altogether, and having your first meal around 1pm, with your last feeding time around eight to ten pm —but you can also have your eating windows between eight am and four pm, as it’s really up to you. Coffee, tea, and water are allowed during the fast, and a splash of milk probably won’t make much of a difference, if absolutely necessary. If you follow the Leangains strictly, they do have a strict nutrition plan, as per their muscle-building purpose. However, a recent study at the Salk Institute for Biological Studies found that mice who feasted on fatty foods for eight hours a day still didn’t become obese or develop high insulin levels.

  2. Weekly Intermittent Fasting - Even fasting occasionally can bring some of its associated health benefits, with less of a commitment. This method, developed by Brad Pilon, proposes one 24-hour fast per week. This obviously entails less weight loss than if you adopted more consistent fasting, but it can be a great way to introduce the idea. It really isn’t that difficult, either. Let’s say you have lunch on Monday at one pm as your last meal. You can eat again on Tuesday at 1pm, so you’re really eating every single day and just taking a 24-hour break in the middle. They’re great to throw in during a long period of travel, a particularly busy day, or after an overindulgent holiday. The best thing is, the rest of the week you can eat however and whatever you want, although if you’re trying to lose weight, your meals should be healthy and include lots of lean protein, fruits and veggies. You can also step it up to Alternate Intermittent Fasting, which is the same thing, but you fast three times a week instead of just one, timing it so that you still have at least one meal every day.

  3. Warrior Diet - Ori Hofmekler created the Warrior Diet based on the ideas of dietary stress and circadian rhythms. The idea of dietary stress follows the same principles of physical stress that are present in working out. Exercise stresses and pushes your body and builds muscles, stimulating fibers, ligaments and the nervous system. Hofmekler proposes that dietary stress is similar, triggering response agents like anti-inflammatory and immune molecules. The Warrior Diet doesn’t technically incorporate fasting so much as periods of severe under-eating which can last from 12 to 16 hours, including sleep. You’re allowed one four-hour period of feasting at night, which is supposed to be evolutionarily correct and follow the natural rhythms of the Earth. The disadvantage is that the food you’re allowed to have is quite restricted, the small meals during the under-eating period are very specific and there are also rules for the order in which you can eat your main meal. It also incorporates supplements.

  4. Fat Loss Forever - This combines elements from the other three. You get one cheat day, with a 36-hour fast right after, and the remainder of the week is split between the different types of fasting. John Romaniello and Dan Go contend that their program, which includes a detailed workout plan and supplements, is the solution to being able to lose those last, pesky fifteen pounds and achieve your “omega body.” They suggest leaving the longest fasts for your busiest days, so you notice them less, and keep occupied. This approach works best for people who enjoy structure and a timetable, but may be difficult if you have issues with handling cheat days in a healthy manner.

  5. The 5:2 or Fast Diet - Both Dr. Michael Mosley and Kate Harris wrote competing books proposing basically the same diet plan, within months of each other. This is another case of severe calorie restriction rather than actual fasting, where participants eat healthily but however they wish for five days a week, and reduce severely the other two days — 500 calories for women and 600 for men. Though some people report feeling lightheaded and lackluster on the low-calorie days, it seems that the overall flexibility afforded by the diet plan makes it easier to stick with in the long term.

All told, Intermittent fasting is definitely not for everyone, and its oft-touted benefits haven’t yet been backed up by enough hard science. If you lead an active lifestyle, exercising on an empty stomach can be extremely difficult, though some people claim that it gives them more grit and stamina.

When looking for a diet program, the most important factor is you. If the plan seems too vastly different from your normal eating patterns, then odds are it will be more difficult for you to stick with. Everyone’s body is different. Some people are grazers, and 6 small meals throughout the day work great for them. If this sounds like you, our ten best diet plans of the year is a good place to start looking, and can help make you more conscious of calorie and portion control.