There is an advertisement on our left sidebar for a weightloss program that is worth testing. Basically, you get unrestricted eating for five consecutive hours then water after that. For example not eating before noon and not eating after dinner.
The Fast-5 Diet is a way of eating that facilitates weight loss. Exercise is encouraged but not required.
There’s no membership fee or hidden cost.
There is no food off limits.
No special foods are required.
Calorie counting is not required.
The Fast-5 diet is not just a weight-loss diet — it is a comfortable way to live to maintain a healthy weight indefinitely.
The Fast-5 diet is a form of intermittent fasting with a daily short fasting period (19 hours, including sleeping) followed by an unrestricted eating window of 5 hours.
Guide to the Fast-5 Program
During the five consecutive hours (the “eating window”), eat as much as you’re hungry for, and eat what you want to eat. As long as you keep at least a nineteen-hour fast daily and eat within five or fewer consecutive hours, you’re within the guidelines of the Fast-5 program. Any window of five consecutive hours can be used.
What to expect on the Fast-5 Program
Expect zero weight loss in the first three weeks, which is the adjustment phase. You may even see weight gain during this period due to compensatory overeating. Weight measurement during this time is not recommended, but many people can’t resist, so don’t expect a loss. Three weeks after starting the Fast-5 program, you should see an average of a pound per week loss. That means over the course of four weeks, you should see four pounds lost, but the loss may not be evenly spread from week to week; it can be two pounds one week, none the next, then two again, and so on.
Some people see more rapid weight loss, even in the first three weeks. That’s not a problem, but may not be seen by everyone, and is less likely for someone who’s already been maintaining a low-carb diet. An early loss of several pounds early is likely to be mostly water, so if you see a large early loss, do not expect to see the same rate in later weeks.
How to start the Fast-5 Program
There are two ways to start, “cold turkey” and a gradual “adjustment” approach.
1. Cold Turkey
In a cold turkey start, one simply chooses to not eat until the eating window opens. This approach is usually effective but may require a number of “close” days before finally reaching the target time. Using this approach, the third, fourth, fifth day is typically the hardest to get through, and after this “crunch” day, the days get easier quickly.
Key to remember: If you slip and don’t reach your goal, don’t give up. Getting close to your goal pushes your body to adapt, which can make it easier to reach your goal on your next try. Slips are a normal part of adjustment.
2. Adaptation
In the adaptation approach (extensively described in the book), the time one first eats (called break-fast and pronounced “brake-fast” to avoid confusion with breakfast) is gradually pushed back. The time of break-fast is pushed back by the same interval (half an hour or an hour) every day or every few days until it is the desired window opening time.
One can also adapt using the “ratchet” approach, in which you don’t eat until at least 15 minutes later than yesterday’s break-fast time, but if you’re not truly hungry at that time, you wait until you are. With this approach, you postpone break-fast by whatever time increment your body’s ready for. Some days break-fast may be 15 minutes later than the day before, and some days it may be an hour or more later, but it doesn’t fall back.
Key to remember: Same as the cold turkey approach: If you slip and don’t reach your goal, don’t give up. Getting close to your goal pushes your body to adapt, which can make it easier to reach your goal on your next try. Slips are a normal part of adjustment.
Effects of the Fast-5 Program
The Fast-5 way of eating works because it restores appetite to an appropriate level for the amount of stored energy (fat) you have and the amount of energy you expend in a day. You take in less food so your body burns more fat. Binge eating may occur during the adjustment phase of the program, but doesn’t typically persist.
Reports on Fast-5 way of eating.
Inches before pounds – Inches seem to disappear before the weight comes off. Probably due to fat redistribution, this means a Fast-5er typically will see loosening of belts or pants before the weight loss is seen on the scale.
Feeling cool or cold when they’d usually be comfortable – this occurs during the fasting period due to the absence of heat generated as a byproduct of digestion of the usual meals. Digestion is metabolic activity, but the energy burned by digesting food is less than the energy that gets stored, resulting in a net gain of calories and fat. While the absence of digestive heat may mean wearing an extra layer in cold weather, it also means greater comfort in warm or hot weather. After starting Fast-5, the heat byproduct of digestion may be more noticeable after break-fast because it hasn’t been going on constantly.
Decrease in symptoms of inflammatory and other diseases:
Fast-5ers have reported diminished symptoms of: rheumatoid arthritis, multiple sclerosis, asthma, congestive heart failure and a reduction of insulin requirement for type 2 diabetes.
Fewer meals, less food, and less time spent preparing meals means more time and money for you to spend as you wish.
Can I move my window to 3-8 or 1-6?
Yes. Any five-hour window should work. The primary reason for having the window late in the day is to avoid having a time after the window is closed during which one must resist temptations (and limbic hunger) until going to sleep. For some, this presents no problem, while for others, it is a significant one. Fast-fivers have been successful with all sorts of windows, from morning to mid-day to evening.
Isn’t eating late supposed to be bad?
Eating late in the day is not a good idea if you eat breakfast, lunch, and dinner, because it takes away the last opportunity your body has to reach a long interval of low insulin, as shown in the graph on page 49 of the book. Low insulin levels are good for burning fat rather than storing it. If you’re fasting 19 hours a day, it doesn’t matter whether you eat early or late – your body still gets the opportunity to burn fat.
I was losing weight steadily for a while, but now it hasn’t changed in the last few weeks. What can I do?
This time of holding steady is called a plateau. Your body has lost some weight, but isn’t willing to let go of more. The following techniques may help you break through the plateau. Once broken, weight is lost at about the same rate as before, and you may reach other plateaus before getting to your goal weight.
Plateau-breaking techniques
1. For a short time (two weeks or so) increase your exercise by 20% or more.
2. Consciously cut your calorie intake for about two weeks. Consistently cutting half a serving of one item in your meal can be enough.
3. Temporarily cut your window duration from five hours to two or three.
4. If you’re feeling up to it, extend your fast on one or more occasions by 12-24 hours.
5. Try a schedule holiday – a day or two off of the Fast-5 schedule, then return to your usual schedule.
People holding at a plateau weight using Fast-5 have reported having increased hunger just before the weight loss begins, so try to think of increasing hunger as a good thing.
I’m still eating everything in sight. What do I do?
Give yourself time to adjust. Compensatory overeating is a normal part of the adjustment, and typically subsides after a week, but sometimes it takes up to three weeks. Weight loss is not to be expected until you’ve been on a steady Fast-5 schedule for at least three weeks.
Is a shorter eating window okay?
Yes. Fast-5 is designed to be as easy as possible and still work. If you find yourself comfortable with a five hour window and want to try a shorter one, or if a shorter window fits your schedule or preferences better than a five-hour window, shortening the window may improve the long-term benefits of Fast-5 by reducing the time that your insulin level is elevated above the fasting baseline.
Can my eating window be a different time?
Success with a sliding window is likely to vary from person to person and schedule to schedule. This is one of the many places where one should start with a fixed schedule, and after achieving a comfortable “steady state” of weight loss, make changes to tailor Fast-5 to schedule and preferences. If your weight loss stops, it’s easy to go back to what worked. If your weight loss continues, then you have found extra freedom in tailoring the program to your lifestyle.
What can I drink in during the fasting period?
Any beverage of zero or negligible calorie content is fine: water, flavored water, seltzer water, club soda, coffee, or tea. Decaf coffee is suggested in order to reduce the stimulant effects of caffeine. See the “Artificial Sweetener” question below for information on artificially sweetened beverages.
What should I eat?
Decide what you think is the healthiest diet, much like any parent would choose for his/her kids if they would eat anything and everything offered.
A variety of fruits and vegetables with a generous amount of fiber
A variety of protein sources: fish, eggs, meat
Nuts or sunflower seeds.
A balance of carbohydrate, fats, and protein with no extremes. Reducing carbohydrates (bread, pasta, rice, potatoes, cereals) may enhance weight loss by an additional effect on appetite moderation.
Can I combine this with low-carb (Atkins, South Beach)?
Yes. Fast-5 can be combined with diet programs that specify content, such as a low-carb diet, an ADA diet for diabetics, etc.
Can I chew sugarless gum or candy
Sugarless gums and candy often contain calories because they contain sugar alcohols such as sorbitol, so this would not be consistent with fasting. Chewing and/or the sweet taste, even without calorie content, may trigger gut activity and increase hunger. If it’s important to you to have gum, you can compare Fast-5 with gum and without gum for a couple of days each way and see if you notice any difference. For candy sweetened with artificial sweeteners, see the artificial sweeteners question.
How can I see quick weight loss with your plan?
Fast-5 is not a quick weight loss plan. It’s powerful, effective, and sustainable, but it’s not quick. A pound per week is the typical sustained average weight loss. In the tortoise-and-hare tradition, it is more likely to get you to your goal than a “quick” solution. For most people, a pound per week is much faster than the rate at which the excess weight was gained.
What about artificial sweeteners?
Artificial sweeteners are acceptable but should be minimized. Even though they’re artificial, they may trigger insulin release through taste receptors, which can lead to reduced fat burning. If their use helps with weight loss, then the overall health balance of good vs. bad favors using them, but it would be best to get used to drinking beverages without them.
What about stevia?
Stevia is a natural non-caloric sweetener not approved as a food additive by the US FDA, so you won’t find it in any beverages. It is, however, available as a supplement in the USA and is widely used around the world. One should not conclude any product is safe simply because it is natural—the deadly toxins ricin and botulinum toxin are completely natural too. Recent toxicity studies have shown no significant threat in using stevia. When hundreds of millions of people have used it thousands of times, as they have with Nutrasweet and Splenda, hidden problems may become evident. Like the artificial sweeteners, the sweet taste may elicit some insulin response, so minimizing use would be a wise choice.
What about putting lemon juice in my tea or water?
No problem. Not enough calories to have an effect.
I’m hungry all day some days. What can help?
Fast-5ers report that high carbohydrate (bread, rice, pasta, potatoes) intake usually lead to more hunger the following day. You may want to trim your carbs. Increased hunger may also mean you’re about to start dropping weight again after a plateau period.
If you ate everything you needed to in order to get all the nutrients you need to survive, wouldn’t you be extremely stuffed?
No — consider this: What do we need nutrients (food) for?
1) fuel – energy to supply bodily functions
2) structure – spare parts to replace what’s used
As for #2, the body is very, very good at recycling. When cells or parts of cells grow old, their parts are largely reused. For someone who is not growing, pregnant, or breast feeding, the need for these spare parts is tiny compared to our need for fuel.
For #1, fuel, yes we need fuel, but if it is stored on our bodies already as fat, then we don’t need to be eating fuel. For those wanting to lose weight, the idea is to “eat” the stored fuel — as Carrie of the Fast-5 Yahoo group put it, she wants her body to go “eat” her thigh.
There is a lot of exaggeration about how much nutrient intake we need to live. Much is due to marketing and some is planned in order to avoid vitamin deficiency. The US RDA, for example, was developed based on micronutrients, not total calories, when obesity wasn’t much of a problem. It used a 50% excess of content to make sure sufficient micronutrients (vitamins, etc.) are available in an “average” diet for the “average” person.
Can I eat ___________?
Many people have asked if they can eat various no-carb foods such as olive oil or protein shakes during the fasting period. Eating anything during the fasting period, even if it does not produce an insulin surge, may impair progress on Fast-5 because eating calorie of any sort may activate limbic hunger which instinctively prompts a person to eat more once the first bite is taken. Limbic hunger (p. 12 in the book) can be difficult to resist.
However, no two people are alike and what is a problem for others may not be a problem for you. What works for you is all that matters, so you can try any modification of Fast-5 you wish. If your modification works, you keep losing weight. If it doesn’t, you stop losing weight. You can always go back to what worked, and all you risk by trying something new is your rate of weight loss. Once you’re started on Fast-5 using the traditional style (no calorie intake during the fasting period) and see some steady weight loss, you know what works. After that, you can experiment and see what modifications work for you.
Comment about the fast-5 program.
I see that alot of people here tried fast-5 or some other type of IF this summer and I’m wondering how you guys are doing now?
I started fast-5 on Wednesday, but I’m acclimating so I ate at 12. Then Thursday I ate at 2. By Friday I’d lost 2 lbs and felt that weird taste in my mouth that the pdf talked about. Overall, I’m super excited!!! The science seems so obvious, so real, true.
This last year has kicked my butt. I was gaining weight constantly, stress eating, and by March I was topping my most ever non-pregnant fat wieght at 183. We were running out of savings while my husband finished a three year project creating an rpg computer game, Depths of Peril, that just recently came out. I was freaking out about the money and about the unknown (not knowing what would happen when the game came out). Plus, I have alot of writing in the game and I didn’t know what that meant for me or my writing career. Besides stressing out about all of that, I was stressing about my weight spiralling higher, my spiking blood pressure (distolic over 90), and the serious heart burn resulting from too much advil (headaches due to blood pressure) ripping up my stomach.
By May, I was on Meridia (part weight loss, part anti-depressant), which I took for nine weeks. It really helped with the anxiety. I noticed right away that things weren’t making me tence up the way they used to. But for that luxury, I felt car sick anytime I shopped (groceries) or spent time on the computer. I lost eight pounds and gained back five when I went off the drug, but my weight steadied at 177.
I am thin at 140, so I need to lose 37 lbs. I’m extremely positive and excited about fast-5. It just makes sense! I’ve not been very hungry during the day. The biggest thing is psychological, the times I think I “should” be eating. But I’m stubborn as hell. 
And when I’m not eating, I can’t stress eat.
I did weight watchers five years ago with my husband and lost 30 lbs. But after two years, it started creeping back. I tried ww several times after that, but I couldn’t stick to it. The result was that I yo-yoed myself up to new heights. It was very frustrating and depressing. 
I really think fast-5 is exactly what I need — long term. I can’t wait to get my body, and more important these days, my health, back for good.
Delilah
Hi Tom,
I’m having a little trouble with the navigation of your site, so I figured I’d just message you directly to thank you…!
The link on your website [for the Eat Stop Eat program] indirectly proved to be THE SOLUTION for me. I started research the Eat Stop Eat program and, in the process, I encountered a similar intermittent fasting program – and way of life: Fast-5 (http://www.fast-5.com/).
Granted, I’m only on Day 3 of the program; however, I’ve struggled long enough to know that this IS the solution for me. It’s the most amazing form of healing I’ve ever experienced. If it weren’t for your site, there’s not telling how long it would have taken me to discover this… (if ever).
Thanks so much!
-Amy (aka TheRisingStar456)
Hi Tom, Keith and everybody in this site.
i’ve been struggling with the this problem for a long time. since 1988, after my first pregnncy I gainned a LOT OF WEIGHT. Before that I used to weight 53 kilos and ended up at 86kg.
I’ve been using fasting as a weight loss for some time now. Water and juice fasting. The first time. I first juice fast in 2003 for 7 days. In 2006 I water fast for 9 days. In the midtime I juice and water fasted for 3 days EVERY WEEK. I lost some weight, but as soon as I restarted eating I couldn’t keep the weight off. I’m pretty atlhetic: I swim 2.000m 4 or 5 times a week and the juice has always been very energetic and detoxing for me during my practice sessions.
Well, some days ago,I saw here the aarticle about Fast-5 and got very excited. Started imediatelly, and because I’m used to water fast for a few days it wasn’t very dificult for me to start cold turky, which means.. so need to delay the first meal until 5pm. It made a lot of sense to me because my worse part of the day during a fast was always the evenings and nights, until 6pm it was pretty easy to fast.
I have to say I’m pretty amazed by the program so far… It’s been very easy to follow the 5hours feeding window everyday and although it’s not expected to see any wieght loss in the first 3 weeks, I’ve got rid of 3 kg in JUST one week. I’m now on the second week nd feeling great. I’ve just been on a 6 days juice fasting right before trying this fast-5 diet and have lost 6kg. when I started I weighted 80 and yesterday I was at 77kg. I’m SOOOOO excited about this program.
Since I’m used to eat a lot of fruits and juices, I’ve been opening my feeding window at 5pm with fruits and protein shakes with fruit or vegetable juice everyday and having a regular dinner with family at 7pm ( rice, beans, meat, salad, sometimes pasta, and fruit) and at 9pm I have some more to eat like fruit or some cookies and another protein shake.
I’ve never eaten so much and lost weight at the SAME TIME….I dont’t feel hungry or anxious the WHOLE DAY because I don’t feel deprived of anything… If I feel like eating something I know I can have that at my feeding window soooo it’s very easy to wait until there.. everybody I know about this lifestile. My oldest daughter is almost 22 years old and she is follong this lifestile with me and gettting amazing results as well. My husband and my young girl are both delaying their first meal to join us at the 5 to 10 window.
The shopping for groceries and vegetables has been so different yesterday afternoon… I wasn’t hungry and didn’t feel the need to buy so many things… and since only 2 of us 4 are having 3 meals a day I saved a lot of money because I bought half the amount I used to.
The hormones explanation about the way our bodies burn fat for fuel made so much sense that I’m telling
I’m sooo happy and if it weren’t for this site who knows how long it would take for me to struggle…
best regards
ELIA REGINA
HI ELIAREGINA…
Thank you for keeping us posted on your fast-5 progress!..
this will be verry inspiring for others on the site…
i wondered where you were hiding!..lol…
Thats great the family are joining in with you, please keep us posted on further progress?..nice hearing from you eliaregina.
best regards keith.
Hi Keith,
I’ll keep you posted for sure. I’ll not hide for more than a week or two, ok? lol
best regards
Elia Regina
Hi Keith
I’ve been reading the posts at the site and I’m very proud of you. You have accomplished a great goal. Hope you have found the enlightening you’re looking for during your water fast and hope you’re enjoying your juices.I love them. They cured me from seeral inflamation at my hands due to computer use during work in 1998 and since then I’ve been drinking at least 4 250ml-glasses of juice a day and my family has done the same. We haven’t health insurance anymore. It’s very expensive here in Brazil, and we haven’t had a doctor appointment since than. I’m 48, my husband 49 and my girls 21 and 17 and we’ve been free of all kind of prescribed drugs for more than elevem years because of juices. they are very tastefull and we have a great variety of fruits available all year round, so we take advantage of theprice of tropical fruits we have here.
Like I promissed, I’m here to update about my experience with fast-5.
Yesterday was he last day of my second week. So far so good.
At the first week I was really concerned about the exageration during my feeding window but now I”m more relax aboout it. it certainly is getting better and I’m beeing more selective at choosing my food. My weight is at 80kg and haven’t changed for days, but I’m not concerned because I’m feeling a lot more confortable in my jeans than I’ve felt in a long time.
The weight loss is expected to start after the third week because of the adaptation phase, so everything is the way it should be.
next week I post again to update you.
best regards to everybody… I hope you all do great at accomplishing your health… this is the most important and precious thing we can have.
best regards
Hi Eliaregina
Thank you for letting me know of your progress on the “Fast-5 weight loss diet update,can you post your update on the “Progress Reports page. It would be nice to hear your comments you have,and share your views with others?
Thank you again for your update.
Best regards Keith.
wouldn’t the 19 hours of fasting put your body into starvation mode so that during the 5 hours of eating wouldn’t your body hoarde all that food & store it as fat because the body thinks it’s starving?
Hi Nikki
Eliarigina keeps me posted on her progress with the Fast-5.
Her family are on this diet and doing really well, aparently on the first 3 weeks you can expect to put on some waight as the body adaps to the 5 hour window, waight loss should be expected after the 3 weeks even before this! you can try playing around with the food that you eat to gain the best results..ie reducing carb and adjusting your cal intake.
On this diet flavoured water, seltzer would be best.
Tom can give you more advice on this diet but at the moment he is having problems with his internet connection due to a typoon in the philipines,
Hope this helps you for the moment
Best regards Keith.
hello, i’m giving this a try but finding it pretty hard, as i have a big family to feed. meals and snacks tempting me. any ideas of what i could turn to to help me through the beginning phases of self-control? right now i’m drinking diet cranberry juice and chewing gum, if it get’s too intense i’ll grab a sucker or piece of hard candy……i’m trying to work my window to the hrs. of 2pm.- 6:30pm. so that way i can enjoy an after school snack with my kids and eat dinner with the family!
any suggestions please!
thank-you
Hi Turquoise
Candy will make you more hungry as it is loaded with sugar giving you an energy spike, then a energy slump making you feel even more hungry. Get your family involved in supporting you, chew on a carrot if you feel hungry or a banana, and try and get yourself into an exersising program.
even buy yourself a jogging/walking machine, power walking is amazing for shifting weight loss,
my waight 2 years ago was 15.5 stone, after power walking 5 days a week, 1 half hours a day for 1 month, i lost 28 lbs.
Best wishes Keith.
Hi keith and everybody from Fasting.ws
I’m here to update you about my fast-5. I’ve been doing this since midle september. I started at 80kg and I’m now at 76. I’ve got rid of 2kg each month, total of 4kg until now. It’s just what was expected to happen.I’ve been eating whatever I want during my feeding window, no deprivation, thank God. I’ve been swimming 2.000m twice a week and riding my bike around for 1h1/2 during weekends. so far so good.
The first 3 weeks I had a lot of exageration on my feeding window. sometimes I went to bed completely sttufed. I guess it’s because we try to store for the next fasting time. But after 3 weeks I didn’t have problems on fasting for 19h, except that one hour before the window opens I am REALY hungry, and knowing that, I try to let some fruit ready on a bow at the fridge for opening my window with it.
During this time I had a period when I didn’t fast-5 for one week due to traveling for attemding a family wedding. I thought it would be difficut to explain and people get sooo upset if you don’t show apreciation for their cooking skills when you get together that I prefered to skip a ween than to give a lot of explanation.
I experimented a lot during this time. I swichted my window from 5-10pm to 1-5pm but it didn’t work for me because in the evening, in front of tv I wanted to eat again and sometimes I cheated, so I decided to have a 5-10pm window on weekdays, skipping lunch and opening my window at 5pm with a huge fresh fruit portion and a fresh fruit juice. at 7pm dinner with my family and at 9h30pm some almonds and sometimes a candy. at 10pm I close my feeding window and until it opens again I spend 19hours on destiled water only.
On sundays I make my window from 12-5pm because having lunch together on sunday is a tradition for brazilian families, but on Mondays the fasting is of 24h because I fast from sunday 5pm until monday 5pm when my window opens again.
Not even a soda or a bublegum durng the fasting time. only diet sodas, but I don’t like them very much. If you read the ebook you’re going to understand that there should be no glucose at all on your system during the 19h fasting time because of the hormones our bodies produce that make the body store fat. It’s necessary 14h for the 2 hormones get to level zero and only after this 14hours our bodies are going to start burning fat and it will do it for 5hours until the 19hours fasting is complete and the feeding window opens again.
This month (november) I’ve noticed a loss of 300grms every other day, but I don’t know why. Maybe My metabolism is getting more accelerated. So I expect to loose more than 2kg this month, let’s see what is gonna happen.
next month I’ll update again…
best whishes…
Hi Eliarigina
Thank you so much for your update, this will help those about to start the fast-5 diet, Soda as you know causes a build up of gasses in the gut making you feel bloated, thats the only thing i can say to you as i have never tryed the fast-5 diet, im glad to hear from you as i always look forward to your progress on this diet, the waight loss is great. Are your family still on this diet?…let me know on your next post
God bless Keith.
Hello everyone, I am new to the site and have only been reading the info here for a couple of weeks. I am working my way back into the Fast-5 type agenda and have lots of weight to lose. I originally ate like this many years ago, having worked myself into the one meal a day routine on my own. I would do it from time to time, but would always slip back into old habits. About 7 or 8 years ago I started this regimen again and was losing lots of weight, averaging about 15 lbs a month and ended up losing 90lbs. I exercised a lot also…walking, kettlebells, clubbells, weights. Lots of coworkers etc. kept telling me how unhealthy it was, but I was feeliing GREAT. Isn’t is amazing how many experts are out there?
About that time Ori Hofmekler published the book Warrior Diet, which is very similar, encouraging one meal a day. So when these “experts” started their verbal upchuck I would shove the book in their face. Being as obese as I am (I have since regained the weight) was not healthy either!!!
Eating once a day is no problem for me, but the caffiene probably will be…not coffee, but sweet tea….I live in Georgia….The South! I have my own distiller and will be drinking water from it. I have gout and drinking extra water will help with that. I have fasted for up to 3 days a time or two, and hope to work into eating, maybe 5 meals a week. Encouragement is gladly accepted, and I will try to repay.
Hi RandyJ
When you look back 7-8 yrs ago how did you feel when you were going to the gym?…I bet you felt really great about yourself?
All you have to do is put one foot forward in the right direction and go for it!
All you need is determination and sheer willpower.
Yeah do the fast-5 diet eating in the 5 hour window, but get yourself back into the gym to boost the endorphins and feel good about yourself, don’t let people put you down.
Blessings Keith.