This is the same as the 8-to-6 window plan, but you are extending your fasting time an extra four hours. I personally practice this plan during the workweek. I'm not a breakfast person, so I just enjoy a few cups of herbal tea to start my day. With this plan you will be eating only between the hours of 12 p.m. and 6 p.m. for a full 18 hours of fasting within a 24-hour period.


Hunger suppression. A ketogenic diet suppresses hunger, too.[16] On a keto diet, your liver turns fat into little bundles of energy called ketones, which it then sends through your bloodstream for your cells to use as fuel. Ketones suppress ghrelin, your body’s main hunger hormone.[17] High ghrelin makes you hungry. On keto, your ghrelin stays low, even when you don’t have food in your system. In other words, you can go longer without eating and you won’t get hungry. Fasting becomes significantly easier on keto so you can fast for longer windows to reap all the benefits.
16-hour fast (aka 16:8): The most popular type of intermittent fast, the 16-hour fast encourages you to eat all of your meals in an 8-hour window, such as noon to 8pm. To activate the full benefits of intermittent fasting, try an 18-hour fast, once you’ve adapted to 16 hours. This would mean eating between noon and 6pm or between 2pm and 8pm. Simply avoid eating after dinner, and skip breakfast in the morning. Limit carbs to dinner.
It doesn't matter when you start your 8–hour eating period. You can start at 8am and stop at 4pm. Or you start at 2pm and stop at 10pm. Do whatever works for you. I tend to find that eating around 1pm and 8pm works well because those times allow me to eat lunch and dinner with friends and family. Breakfast is typically a meal that I eat on my own, so skipping it isn't a big deal.

16-hour fast (aka 16:8): The most popular type of intermittent fast, the 16-hour fast encourages you to eat all of your meals in an 8-hour window, such as noon to 8pm. To activate the full benefits of intermittent fasting, try an 18-hour fast, once you’ve adapted to 16 hours. This would mean eating between noon and 6pm or between 2pm and 8pm. Simply avoid eating after dinner, and skip breakfast in the morning. Limit carbs to dinner.
IF as a weight loss approach has been around in various forms for ages, but was highly popularized in 2012 by BBC broadcast journalist Dr. Michael Mosley’s TV documentary Eat Fast, Live Longer and book The Fast Diet, followed by journalist Kate Harrison’s book The 5:2 Diet based on her own experience, and subsequently by Dr. Jason Fung’s 2016 bestseller The Obesity Code. IF generated a steady positive buzz as anecdotes of its effectiveness proliferated.
This is a new area, but the research that has come out since this article is also positive, and promising. One example: In this June 2018 study of 23 people with obesity, 12 weeks of 8-hour time-restricted feeding resulted a 2.6% decrease in body weight and a 7 point decrease in systolic blood pressure, which was significant when compared to controls: https://www.ncbi.nlm.nih.gov/pubmed/29951594

I would like to know what led you to the conclusion to recommend eating in the morning and fasting in the evening instead of the other way around. You do not link any studies here that show TRF in the morning is better than TRF in the evening. You do state “Nighttime eating is well associated with a higher risk of obesity, as well as diabetes.” but I would hazard a guess that alot people that snack into the evening have many other factors at play that could effect their risk of obesity and diabetes and are possibly not fasting at all. I have been doing TRF from 12-8pm every day for almost a year and have seen vast improvements in my health, not least of which is a loss of 70 lbs, so it seems odd to read items 3 and 4 on your 4 ways to use this information for better health. If you have evidence that supports the idea that TRF in the evening is bad then I would like to see it and perhaps change my dieting habbits.
Intermittent fasting is a technique that involves restricting your food intake to a certain time window each day and then fasting for a specific period. There are several different fasting methods, with many variations that can fit nearly any personal preference or routine. A few of the most common types of intermittent fasting include alternate day fasting, 16/8 fasting and the 5:2 diet, each of which varies based on the amount of time you spend fasting during the week.
Hunger suppression. A ketogenic diet suppresses hunger, too.[16] On a keto diet, your liver turns fat into little bundles of energy called ketones, which it then sends through your bloodstream for your cells to use as fuel. Ketones suppress ghrelin, your body’s main hunger hormone.[17] High ghrelin makes you hungry. On keto, your ghrelin stays low, even when you don’t have food in your system. In other words, you can go longer without eating and you won’t get hungry. Fasting becomes significantly easier on keto so you can fast for longer windows to reap all the benefits.
You’re consuming less food and thus spending less money. Rather than overeating to put on 1 pound of muscle and 4 pounds of fat in a week or two, you’re aiming to eat exactly enough to put on 1 pound of muscle without adding much fat on top of it.  Yeah, it’s a delicate balance, but there’s far less swing involved. You are just slowly, steadily, and consistently building muscle and strength over many months.
Because we don't enter the fasted state until 12 hours after our last meal, it's rare that our bodies are in this fat burning state. This is one of the reasons why many people who start intermittent fasting will lose fat without changing what they eat, how much they eat, or how often they exercise. Fasting puts your body in a fat burning state that you rarely make it to during a normal eating schedule.

So, the idea that intermittent fasting is bad for women is only partially true. Your body will do strange things if it thinks it’s starving. That’s normal, expected, and part of your evolutionary biology. The key to making it work is to give your brain the energy it needs and assuring your metabolism that everything is a-o-k and you’re not in the middle of a famine or disaster.
So, what exactly is a relaxed approach to intermittent fasting? Again, since there’s little research done on intermittent fasting, we’re dealing with a bit of a gray area. The opinions also tend to vary depending on which site you visit, or which health expert you ask. From what we’ve found, the general guidelines to brief intermittent fasting for women are:
Nuts and seeds make great snacks that are high-fat and can be eaten around 2:30 p.m. Soaking these beforehand can help neutralize naturally occurring enzymes like phytates that can contribute to digestive problems. Eat dinner around 5:30 p.m., and just like the 8-to-6 window plan, a dinner with some sort of wild-caught fish or other clean protein source with vegetables is a great option.
Tons of celebs are jumping on the intermittent fasting keto bandwagon, and for good reason. The two work hand in hand to accelerate weight loss, not to mention stimulate lots of other performance-boosting benefits. Fasting is an extraordinary tool for improving your biology. It’s free. It’s universally accessible. It’s adaptable. It’s the reason it’s always been a major part of the Bulletproof Diet.

Put a coffee filter or your cheesecloth (you can even use a paper towel if you don’t have a coffee filter/cheesecloth) into the mesh strainer and place it over another glass container. Gently pour the filtered coffee through the filter and let it slowly drip into the glass container below. If the filter fills up, just wait and let it drip naturally (this could take up to 10 minutes).


Eating all your meals in an 8-hour window (say, eating between noon and 8PM, and fasting the other 16 hours a day) causes significant weight loss without counting calories.[1]  While this type of intermittent fasting causes weight loss no matter what people eat, research shows that people who do it in a healthy manner lose twice as much weight (7% vs. 3% of their body weight) as those who fast while still eating junk. So it’s still important to follow a high-performance diet like the Bulletproof Diet while you fast.
I’ve read several places that adding gelatin or collagen to coffee breaks the fast, but I don’t understand why since there are no carbs, only protein, and fewer than 50 calories per tablespoon. Have you tested this? It would be great to be able to add protein to my morning coffee so I would love to know. Would also love to know if one tablespoon of coconut cream affects ketones and glucose.

I have since reviewed another new and amazing intermittent program called Science Based Six Pack, you can read my full in-depth review of this program here, Science Based Six Pack Review. I have also purchased this program as well, and it is very thorough and detailed, as well as very user-friendly. This is my new number #1 recommended program for a highly effective intermittent fasting program.

Although there's no specific dietary recommendation when intermittent fasting, many people choose to combine it with a low-carb, ketogenic diet. When it's time to eat, include foods that are high in good fats and low in carbohydrates. That means eating nuts, seeds, vegetables, avocado, olives, meat and fish, while avoiding whole grains, fruits, starchy vegetables, sugary drinks and anything processed.


It has totally regulated my appetite and normalised my relationship with food. My obsessive thoughts have completely subsided, my black and white thinking around food has gone, and I no longer binge! This is amazing. For the first time in my adult life I feel like I know what it is like to have a normal relatinoship with food. I eat when I eat, a range of healthy whole foods and occasional less healthy foods. In normal amounts. In manageable amounts. And when my meal is over, I stop! Normal for others, a seeming impossibility for me (and, I’m guessing, others with eating disorders).
Autophagy is spring cleaning for your cells. It’s Latin for “self-eating,” which is spot-on: when autophagy turns on, your cells sift through their internal parts, get rid of anything that’s damaged or old, and install shiny new versions.[8] Autophagy is like a tune-up for your car: afterward everything runs more smoothly. It reduces inflammation and even boosts longevity. Intermittent fasting triggers, to quote researchers, “profound” autophagy, especially in your brain.[9]

For example, in the graphic below you would eat dinner on Monday night and then not eat again until Tuesday evening. On Wednesday, however, you would eat all day and then start the 24–hour fasting cycle again after dinner on Wednesday evening. This allows you to get long fast periods on a consistent basis while also eating at least one meal every day of the week.
Following what Greg lays out for us, we should wait a couple of hours and stave off our cup of jolt, kick-starter for at least a couple of hours after getting up. Instead, we should have some hydrating water. That’s a hard one, let’s be truthful. Real hard, especially for coffee lovers, but I suppose there is a reason for this. I think this has something to do with cortisol levels. This really helps when, or if you get hunger pains and then have a cup of wakey juice or two or three or four cups. This almost always alleviates the hunger, so this is why it’s so powerful.

This fasting process will not only activate autophagy in your cells, it will also increase your ketones much more quickly than if you were just eating a standard ketogenic diet. If you start implementing intermittent fasting and activities (like walking, cycling, or lifting weights) together, you can raise ketone levels and increase autophagy more than you would with intermittent fasting alone. This suggests that intermittent fasting would be a great addition to your life, but it is important to be familiar with the negative symptoms that can arise before you start.


Harvard-trained physician and author of The Paleovedic Diet, Dr. Akil Palanisamy further explains to POPSUGAR that "autophagy is the self-cleaning process by which the body's cells break down and recycle damaged proteins and components. This is activated by intermittent fasting, but anything other than water (even black coffee) disrupts it to some extent."

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Many people achieve the best results by starting the ketogenic diet first and then beginning intermittent fasting several weeks later. Although this is a bit different from the classic approach to the keto-intermittent fasting diet, it works better for some individuals. This is because intermittent fasting, as previously mentioned, should be a natural process, during which you should not feel deprived and hungry.
In addition, the refined sugar found in most beverages digests quickly, spiking both your blood sugar and your insulin levels. It's also highly addictive. Your body doesn't just want more, it needs more. In fact, according to a review published in Current Opinion in Clinical Nutrition and Metabolic Care in 2013, sugar and sweetened beverages and foods induce reward and craving responses in the brain that are comparable to the responses triggered by addictive drugs, which continue the cycle.
While it’s not technically fasting, some doctors have reported intermittent fasting benefits by allowing such easy-to-digest food as whole fruit during the fasting window. Modifications like these can still give your digestive and metabolic system a needed rest. For example, “Fit for Life” was a popular weight loss book that suggested eating only fruit after supper and before lunch.

This is a new area, but the research that has come out since this article is also positive, and promising. One example: In this June 2018 study of 23 people with obesity, 12 weeks of 8-hour time-restricted feeding resulted a 2.6% decrease in body weight and a 7 point decrease in systolic blood pressure, which was significant when compared to controls: https://www.ncbi.nlm.nih.gov/pubmed/29951594
I don’t recommend that you go straight for a 1-2 day fast, but begin by restricting yourself to certain eating windows. Typically people restrict themselves to the hours of 5pm – 11pm. People often refer to their fasting windows by numbers: 19/5 or 21/3, for example, means 19 hours of fasting and 5 hours eating or 21 hours fasting and 3 hours eating, respectively.

Surprisingly, since I've started intermittent fasting I've increased muscle mass (up 10 pounds from 205 to 215), decreased body fat (down 3% from 14% to 11%), increased explosiveness (set a personal best with a clean and jerk of 253 pounds a few months back), and decreased the amount of time I've spent training (down from 7.5 hours per week to 2.5 hours per week).

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.
Diet soda doesn't contain any sugar, calories or carbohydrates, so it may seem like it's OK for fasting, but it's not that simple. Diet soda and other diet drinks are filled with artificial sweeteners, which can drastically increase sugar cravings, making fasting more challenging. Artificial sweeteners can also increase insulin resistance, which makes it harder to lose weight and increase your risk of developing diabetes.
Before you start your IF plan, it's important to talk with a professional to make sure it's right for you. Women should be especially cautious as there are some mixed opinions on whether or not certain fasting protocols are healthy for female hormone balance. In addition, if you have adrenal fatigue or gut health issues you'll want to proceed with caution. If you have a history of disordered eating, you'll probably want to avoid fasting altogether..
After that timespan, your body goes into what is known as the post–absorptive state, which is just a fancy way of saying that your body isn’t processing a meal. The post–absorptive state lasts until 8 to 12 hours after your last meal, which is when you enter the fasted state. It is much easier for you body to burn fat in the fasted state because your insulin levels are low.
In Prime Women’s recently launched PLATE weight management program, Dr. Kathryn Waldrep recommends eating within a nine hour window and choosing that time frame based on your body’s circadian rhythms. Early risers might eat between 9:00 am and 6:00 pm. Night owls would eat their first meal at noon and finish their last meal at 9:00 in the evening. As more and more research has been done around IF and circadian rhythms, there seems to be more and more evidence on the soundness of this approach to eating for weight management.
It can level up your brain, including positively counteracting conditions like Parkinson’s, Alzheimer’s, and dementia. As explained here in this TEDx talk by Mark Mattson, Professor at Johns Hopkins University and Chief of the Laboratory of Neurosciences at the National Institute on Aging fasting is grounded in serious research and more studies are coming out showing the benefits:
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