In 2005, Dr. Bert showed the world a way to maintain practical, sustainable intermittent fasting with his first book, The Fast-5 Diet and the Fast-5 Lifestyle. In his latest book, AC: The Power of Appetite Correction, he’s added over a dozen tools—all sustainable lifestyle options—to help you achieve appetite correction and fat loss without calorie counting or food restrictions.
With a diverse range of experience, from the no-nonsense world of the US Marine infantry to cutting-edge cancer research at the National Institutes of Health, Dr. Bert maintains a strong sense of practicality and respect for real life. “Life is for the living,” he says. “The way you eat has to be compatible with a life of spontaneity, fun and variety. Losing fat is almost impossible if you’re working against your body, rather than with it.”
Follow Dr. Bert on Twitter & Instagram: @bertherringmd
22 comments
Hi I bought your book when I started a four day fast.. I love how it reminds me fat is fuel. Hence I have lots of fuel. It appears I have no hunger cues so when I eat I have no cue for stopping. For example when I just ended the 4 day water/coffee tea fast (over 12 pounds came off) I ate on the evening of the fifth day not because I felt hunger but I felt fatigued. But the relief from the fatigue was for no more than an hour and I wanted to keep on eating without hunger. Observations and suggestions welcomed.
The lack of hunger cues is one of the reasons that I focus on “appetite correction” as one of the primary benefits of fasting — it’s not just a matter of avoiding intake; it’s getting the appetite system working like it’s supposed to. Most people who maintain an intermittent fasting schedule, even without long fasts, get some appetite correction so they’re no longer hungry and are more easily sated when they eat.
I have restarted on fast-5, after 8 months, but I started taking supplements, would I be able to do my supplements during fasting times, as some require twice a day consumption?
Supplements don’t typically count as a meal, so they’re ok to take during a fast. It makes sense to be open to changing that if you find your fasting isn’t achieving the progress/goals that you expect.
You are one of the best people I have ever known. I do fast 5 and it is so easy and I lose so much weight. I am 86 years old and should lose about 100 lbs, but I have a big problem. As soon as I finish eating, I immeciately need to use the bathroom. This does not seem to happen if I have a small meal before I start the fast5. When I go off it, I need a few days to get back to normal again. Any suggestions?
The connection between filling the stomach and a bowel movement is a well-known reflex called the gastrocolic reflex. It’s most noticeable in babies, who have no reason to suppress it. Consistency in your schedule (not going on and off Fast-5) so that your bowel has several weeks to adjust to a new normal rhythm is likely to provide a more comfortable and controllable response.
Hello Dr Bert.I have bought both of your books and id so much like to purchase your intermittant fasting journal but on Amazon its 150.00 the Spirit Version.Im a housewife and mother of 9 and my son and husband are disabled and I cannot afford this.Do you sell any journals independant of Amazon?I love your program and I hope this is the last time I will EVER have to lose my excess weight due to food addiction/bingeing.Im 100 lb over weight and I really appreciate all youve done to help people lose weight with your website 🙂
Someone must be reselling the book, which is no longer in print. It originally sold for less than $10. We did not keep it in the product line-up because of some limitations in the way it was printed, so we are not selling it anywhere, presently.
Hi Dr. Bert,
I have never done a fasting, and the 5 hour window is something that I am able to do. Am I able to do a 7-1 window? I work from 8-5, but I normally arrive at 6:30 am and my lunch is 12:30- 1:30. I feel like just eating these 2 meals and not eating dinner would be helpful because I normally end up eating 7 or 8 at night right before I go to bed which is not good.
Thank you.
Marie.
Hi, and thanks for writing!
Yes, you can use a 7-1 window; the guide offers 5-10pm as an example, not a requirement. There’s more about this and answers to related questions here:
https://www.bertherring.com/ac/fast-5/faq/
Since you also asked about the $2 book in the shop, I’ll reply here: That’s a pay-your-own-price option for the original e-book from 2005. If $2 is too much, the e-book is available for free. The paperback version and my more comprehensive book (AC: The Power of Appetite Correction) are available on Amazon.
Hello Dr Bert,
Does AC/IF help with menopause and if so, how and what can improve.
Also do you need to restrict calories within the 5 hours or can I eat normally and eat standard carbs like bread, rice, pasta etc?
Thank you
Some women have said that hot flashes and other menopausal symptoms are reduced or absent after making the transition to a Fast-5 schedule. That doesn’t mean all women will see the same outcome, but it could be a nice side effect.
Most people can eat without calorie restriction or food-group restriction during the 5-hour window–this covers about 90 percent. Some people have had tougher challenges and combine some calorie counting or food-group restriction, which is one of the troubleshooting steps mentioned in AC: The Power of Appetite Correction. Because the “Super-BCPs” or SPRBCP – sugars, potatoes, rice, bread, cereal and pasta — make up such a large part of some people’s intake, an impact may be see by reducing them from “main dish” status without cutting them out entirely.
Is there a chance to get the book in Germn language?
The book is not available in German, but the summary and FAQ page are here:
Das Buch ist nicht auf Deutsch verfügbar, aber die Seite mit der Zusammenfassung und den häufig gestellten Fragen finden Sie hier:
https://www.bertherring.com/ac/fast-5/fasten-5-zusammenfassung/
https://www.bertherring.com/ac/fast-5/fast-5-germandeutsch-faq-haufig-gestellte-fragen/
Hi
Can you drink vegetable juice during the fasting period?
Thanks
John
Vegetable juice has calories, so drinking it would end the fast. Some people lose weight on what is sometimes called a “juice fast,” but it’s a juice diet, not a fast, and is probably not a regimen that most people can comfortably sustain.
Thank You Dr. Herring. But I am not just doing AC/Fast-5 for weight control but also to reduce inflammation in order to improve health issues. Wouldn’t I need to be certain that I am in Ketosis in order to maximize the possibility of success with this goal? If so, would it be best to test? IF so, do you recommend urine, blood, or breath testing. BTW: FYI – I am seeing a reduction in inches after 1.5 weeks and I do weigh myself once weekly and after one week I saw 1.5 lbs. weight loss.
Ketones levels are not a good guide because they go up and down for reasons that have nothing to do with how well you’re complying with your fasting regimen or how your body is responding to it. Inflammation is best monitored using a blood test called CRP (also HS-CRP, high-sensitivity C-reactive protein). Done quarterly, it can help show whether many inflammatory conditions are subsiding. To know if it’s working, though, you have to know your starting point. This approach, which can include other helpful tests, is described in more detail in Tool #1, The Study of One, in my book AC: The Power of Appetite Correction. Your doctor may have other suggestions that are more specific for your condition and concerns.
In addition to being primarily Nutritarian I intend to try to apply a permanent IF eating plan for better health and weight control. I am also getting back soon to a regular exercise program. I am trying IF via the Fast-5 Diet. As of now my eating window is modified in that I am doing 18/6 instead of 19/5 The effectiveness of all of this seems to depend heavily upon achieving Ketosis on a daily basis during the fasting period. Do you think that it is worth daily or at least occasional monitoring to be certain that I am in Ketosis? (If so, is the best way to monitor by blood, urine, or breath – and can you recommend a specific product for home use)? Or can I just trust that my body will automatically go into Ketosis? Thank You
Testing for and seeing ketosis isn’t particularly important if you see appetite correction and weight loss. Ketones are likely to be part of what it takes to get appetite correction, but they’re not the whole story. It’s fine to test, and most Fast-5ers we’ve heard from see some ketones in their urine if they test before break-fast. Ketone levels usually fall after adaptation, because muscles and other body parts adapt to using them and scoop them from the blood faster, lowering the level. This means that you may see higher ketone levels early, then less later during and after adaptation. That means that the level doesn’t represent how well your body is responding to fasting; having higher ketone levels isn’t necessarily better. In summary, the goal is appetite correction and (for many) weight loss. If you see those, there’s no need to go to the expense or hassle of testing for ketones. I do not have any product recommendations.
Dear Dr. Bert,
I am very grateful to you for helping me shed my excess 20 pounds that had gradually crept up over the years.
I saw your T.E.D. talk video and followed the Fast 5 and lost 20 pounds in about 3 months with very little effort. I chose to eat breakfast and lunch and skipped food the rest of day except for drinking lots of decaf. tea and coffee with a tiny splash of milk afternoon and evenings. I did feel hungry at times in the evenings but remembered how full I felt the rest of the day and that got me through as I knew that soon I would feel full again. On other diets I always felt deprived non stop every day all day long. And then after losing weight on other diets I would be ravenous in my appetite and gain it all back again. On Fast 5 I ate whatever my appetite wanted during those 5 hours including proteins, fats, and as many carbs as I wanted. I loved to eat all types of fruits and veggies but also indulged at times on cake and ice cream as long as I was still hungry and had eaten a balanced diet before those high calorie desserts with protein ,fats and fruits and veggies. I do like to exercise, so did exercise as well, as I have always been accustomed to doing. But I have never lost weight in the past, just with exercise, so I know it was the Fast 5 that did it, ( for weight loss) not the exercise. In the beginning of Fast 5 I lost about 2 pounds per week and then down to 1 pound a week for the first 20 pounds. I still exercise and have lost 2 more pounds in the past 2 months. I think I have about 2 pounds of belly fat flab to go. I am a little more liberal with timing of meals since I lost the initial 20 pounds. to partake in social events but then I get back to my previous breakfast and lunch eating window. Keeping the weight off has been so easy as my appetite is totally under control, i.e. I want for nothing but have no urge to overeat all day long as I did before when i was 20 pounds heavier. I am 5’10″‘ and at 152 pounds with lots of good muscles from moderate weight lifting and I feel wonderful. I expect that after the last bit of excess belly fat disappears my weight loss will stop. My husband and rest of friends and family say I look skinny ( but not sick, like some people do with other diets). My bones are good and strong and my hair is healthy, not like other diets where my hair would fall out. I am 66 and have the same weight and physique back as when I was in my late 20’s. ( Again my bones and frame have remained strong and just the fat has dwindled away. On bad diets in the past I lost my body frame proportions going from size 14 to size 6. Now on this healthy regime I am a healthy size 10 to 12 with large healthy bones and frame but very little flab left. The best part is I don’t feel hungry, actually feel very full after meals. and maintaining the weight loss has been so easy .)
Again many thanks for your good work. I am spreading your words to all my friends and family and recommending your talk and books and website.
Am enjoying book”AC.” Previously read “Fast-5” book and my spouse and I switched to the 19-hour daily appetite-correction period. Since I think February 2014, I have gradually slimmed down from 225 lbs. to 175 lbs. with no backsliding. The weight came off and has stayed off. My wife slimmed down from dress size 10/12 to size 6, and again no backsliding. She was size 6 when we married 32 years ago. We have shared your information with loved ones, friends and complete strangers. Thank you!