When it comes to intermittent fasting, there’s no one-size-fits-all. Bulletproof Intermittent Fasting fits all your eating into a 6-hour window, leaving you with an 18-hour-fast each day. This is often called “18:6” fasting. You can also try variations such as the one-meal-a-day method, or fasting every other day. The key is to experiment and listen to your body to see what works best for you. If intermittent fasting causes fatigue or other negative symptoms, try fasting just once or twice a week, and build up from there.

As a functional medicine practitioner, I see a wide range of health problems that all stem from chronic inflammation. And while acute inflammation is a natural and healthy response to help fight off pathogenic bacteria and infections, long-term chronic inflammation that doesn’t subside when the threat is gone can contribute to everything from autoimmune conditions to cancer.

Those fasting may experience side effects of fatigue, malaise, aches and pains, emotional duress, acne, headaches, allergies, swelling, vomiting, bad breath, and symptoms of colds and flu. These reactions are sometimes called healing crises, which are caused by temporarily increased levels of toxins in the body due to elimination and cleansing. Lower energy levels should be expected during a fast.
Fasting has been found to have positive effects on body mass as well as other health markers in professional athletes. This is because, as previously mentioned, fasting can effectively shed excess fat, while optimizing muscle growth, because of HGH production. Traditionally, athletes are advised to consume high-quality protein half hour after finishing their workouts (post-workout nutrition) to simultaneously build muscle and reduce fat. Fasting is advised for training days, while eating is encouraged on game days.
The second one is more subtle: The body shifts into fat-burning mode when it doesn’t get food for an extended period of time. That’s because the body’s first source of fuel is glycogen, and it only turns to burning body fat once that quickly available energy source is depleted. So when you fast for long enough, you drive down stores of glycogen and start burning fat tissue. “In people, we see a change in fasting glucose — it’s lower — and abdominal fat is affected without much of an effect on the muscles,” Longo explained.

There are a couple of other caveats here. Fasting diets require working through hunger, saying no to the bagels and muffins put out in your morning meeting or the food at your business lunch. So it’s no surprise that many people can’t stick to fasting diets long enough to keep the weight off. In another 2018 review of the literature on fasting’s impact on weight, the researchers note, “Dropout rates have been as high as 40 percent. Thus, despite the statistical significance of weight loss results, the clinical significance and practicality of sustaining an [intermittent fasting] regimen are questionable.”
Although it may be unfashionable, try to have dinner early and once you’ve finished your meal don’t eat anything and limit your drinking to water or tea. You’re just avoiding bedtime snacks and watching TV without nibbling so you’re not on a diet and since you’ll be sleeping for most of your fast you probably won’t be hungry. It should be a relatively painless way to see if intermittent fasting works for you.

When obese people structured their schedule so that they fasted for 16 hours a day, but were free to eat whatever they wanted in the other eight hours — known as the 16:8 diet, or time-restricted feeding — they modestly lost weight and lowered their blood pressure after 12 weeks on the regimen, a new early study published in the journal Nutrition and Healthy Aging found.


Prayer and fasting is defined as voluntarily going without food in order to focus on prayer and fellowship with God. Prayer and fasting often go hand in hand, but this is not always the case. You can pray without fasting, and fast without prayer. It is when these two activities are combined and dedicated to God's glory that they reach their full effectiveness. Having a dedicated time of prayer and fasting is not a way of manipulating God into doing what you desire. Rather, it is simply forcing yourself to focus and rely on God for the strength, provision, and wisdom you need.
Human growth hormone, or HGH, is naturally produced by the body, but remains active in the bloodstream for just a few minutes. It’s been effectively used to treat obesity and help build muscle mass, important for burning fat. HGH also helps increase muscle strength, which can help improve your workouts, too. Combine these together and you have an effective fat-burning machine on your hands.
A systematic review of 40 studies found that intermittent fasting was effective for weight loss, with a typical loss of 7-11 pounds over 10 weeks. [2] There was much variability in the studies, ranging in size from 4 to 334 subjects, and followed from 2 to 104 weeks. It is important to note that different study designs and methods of intermittent fasting were used, and participant characteristics differed (lean vs. obese).  Half of the studies were controlled trials comparing the fasting group to a comparison group and/or a control group (either continuous calorie restriction or usual lifestyle), with the other half examining an intermittent fasting group alone. A brief summary of their findings:

On weekdays of the first week of Great Lent, fasting is particularly severe, and many observe it by abstaining from all food for some period of time. According to strict observance, on the first five days (Monday through Friday) there are only two meals eaten, one on Wednesday and the other on Friday, both after the Presanctified Liturgy. Those who are unable to follow the strict observance may eat on Tuesday and Thursday (but not, if possible, on Monday) in the evening after Vespers, when they may take bread and water, or perhaps tea or fruit juice, but not a cooked meal. The same strict abstention is observed during Holy Week, except that a vegan meal with wine and oil is allowed on Great Thursday.[47]

Hey! I've been following this site for a while but I'm so busy that I've never been able to get around to a lot of this. I'm a 17 year old female in high school, and I take college level classes and work a lot after school, so I'm constantly busy between work, homework, and school itself. I also lack willpower a lot, which I think is why I struggle to lose weight so much. With such a busy schedule and such little willpower, what do you think would be the best way for me to lose weight and rather quickly (though healthily)? I'm 5'5 and I weigh 240 pounds.
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, Berkhan says.
Lastly, I always start each day (on fasting days I take them with my meal) with a dose of bioavailable multivitamins to fill any nutritional gaps. If you plan on doing the same in the future, just remember to go for all-natural and organic multi-vitamin because synthetic vitamins tend to have no oral bioavailability. New Chapter (the one I linked above) has a high oral bioavailability and is one of the best multis on the market.
Confront injustice through fasting. Fast as a way of expressing poverty in your body, to show solidarity with those who are impoverished by injustice in our fallen world. Divest yourself of some resources – food – for the good of others. Convert what you give up in food when you fast into gifts for the poor by estimating the cost of the food you would have eaten if you hadn’t fasted and giving that amount to charities that help poor people. Use the time you would have spent eating to serve people in need and help bring more justice to the world. Use your fasting to call attention to other people’s needs, such as when you’re working to find solutions to the problems causing injustice and want to inspire others (like government leaders) to take action as well. However, be sure not to call attention to yourself, simply to try to impress others with your fasting. Use fasting to confront injustices in our own attitudes and behaviors, as well – to break the hold of unhealthy habits in your life and help you grow in holiness. Ask God to give you a clear vision of what He would like your life to look like. Then, through fasting, express your complete surrender to that vision.
If you’re eating processed foods and potato chips, it’s unlikely you’ll reap the benefits of fasting. If that’s you, I encourage you to examine your diet before trying a fast. But if you practice fasting and stick to a mostly whole food diet, rich in fruits, veggies, lean proteins, healthy fats and raw dairy, you will see changes — and those occasional splurges on chocolate or cheese won’t have as big of an impact as they might if you were on a calorie-restrictive diet.
Listen to your body during workouts. If you get light headed, make sure you are consuming enough water. If you notice a significant drop in performance, make sure you are eating enough calories (especially fats and protein) during your feasting window. And if you feel severely “off,” pause your workout. Give yourself permission to EASE into intermittent fasting and fasted workouts. This is especially true if you are an endurance athlete.
The five most common methods of intermittent fasting try to take advantage of each of these benefits. But different methods will yield better results for different people. “If you’re going to force yourself to follow a certain method, it’s not going to work,” says trainer and fitness expert Nia Shanks. “Choose a method that makes your life easier,” she says. Otherwise, it’s not sustainable and the benefits of your fasting may be short-lived.
A diagnostic fast refers to prolonged fasting from 8–72 hours (depending on age) conducted under observation to facilitate the investigation of a health complication, usually hypoglycemia. Many people may also fast as part of a medical procedure or a check-up, such as preceding a colonoscopy or surgery. Fasting may also be part of a religious ritual.
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