Intermittent fasting, IE: intelligently limiting your eating window, can help with both the serious and garden-variety digestive problems that come up for many people.
If you regularly experience constipation, diarrhea, gas, or boating, there’s almost certainly a dietary element at its root. I talk about addressing those dietary elements in The Raw Food Digestive Tune-Up. There’s no way to replace addressing those issues, but whether or not you do, intermittent fasting will likely improve your digestive health.
I was diagnosed with colitis more than a decade ago after years of increasingly worse digestive problems, and the only way I could find relief was switching to a diet based around raw fruits and vegetables.
But after awhile I found that limiting my eating to a six or eight hour window took things up a notch. Even if I was eating foods that I knew bothered me, like tomatoes, I could better tolerate them with the shorter eating window. If my eating was pristine, my digestive system seemed to work even better. Quick, full bowel movements, no gas or bloating, and no iffy sensations coming from my gut are some of the advantages I’ve noticed.
Over the years I’ve worked with a lot of coaching clients who suffer from their own digestive problems. Many have food intolerances, have been diagnosed with irritable bowel syndrome, colitis, Crohn’s, or just struggle with bloating and gas.
Intermittent fasting as emerged as a critical piece in helping them to fix their gut problems. But why would it make a difference?
The Science Of Intermittent Fasting And Gut Health
Although gut health is a serious issue in the developed world, intermittent fasting’s effect on it hasn’t been a big area of focus for researchers.
The only research we have into the topic actually looks at longer-term water fasting; i.e., eating nothing and drinking only water for days, weeks, or months at a time instead of hours at a time.
Yet the research we have indicates that there’s a good deal of benefit.
When 58 irritable bowel syndrome patients who’d failed to see any improvements with standard medical care were sorted into a fasting and control group, with the fasting group not eating anything for 10 days, they found significant relief1.
They experienced big decreases in abdominal pain, abdominal distention (bloating), diarrhea, nausea, anxiety, and general interference with their life.
The researchers theorized that this occurred because the digestive rest gave subjects’ bodies a chance to desensitize from food intolerances.
However, there are other explanations. Many digestive disorders, such as Colitis and Crohn’s, and classified as inflammatory bowel diseases; ie, the digestive system is inflamed and autoimmune problems are often cropping up.
Researchers have found that as little as a 24-hour fast dramatically cuts the amount of inflammation in the body2, which could explain things.
You may have noticed that both of the studies I mentioned looked at fasting for at least 24 hours, which is different than the shorter periods of intermittent fasting I’m taking about in this article. So will the beneficial effects carry over?
First off, if you have serious bowel problems, you shouldconsider an extended water-only fast under medical supervision. I’ve done a 26-day fast myself, and several fasts of shorter duration, and felt like each was beneficial. An increasing body of evidence indicates that it’s not only beneficial for gut health, but a wide range of other disorders.
But you can’t be fasting all the time, and that’s where people get into trouble. What you do after your fast is just as important as effect of actual fasting. A good elimination diet should be started after a fast, which I describe in The Raw Food Digestive Tune-Up.
But it’s also be helpful to integrate short periods of intermittent fasting into your day-to-day life, whether you’ve done a longer fast or not. What does this look like? It’s dependent on your lifestyle and what you can manage.
The key is to let your body deplete the its glycogen reserves every day, which kicks ketosis (generating fuel from body fat) and autophagy (the break down of damaged proteins and cells) into high gear. This should happen 16 to 18 hours after you’ve last eaten if you’re not completely sedentary. This will happen quicker if you’re exercising or being more active during the fasting window.
The 5:2 Intermittent Fasting Option
Some people like to take one or two 24-hour fasts a week, and eat normally the rest of the time. I’m way too physically active to make this work myself, but it certainly gives you two fasts of significant length, which will likely to make an impact on your gut health. This is sometimes called 5:2 fasting, and it’s had several books published about it.
The Restricted Eating Window Method
My preference is to eat every day, but only during a limited window of time that generally lasts six to eight hours. I suggest you tailor the start of this window of time for when you have to wake up and when you want to be physically active. Since – after a period of adjustment – you’ll likely find you experience improved mental acuity during your fasting period (after waking up), I suggest you push your eating till sometimes in the afternoon, and stop eating a few hours before bed.
On most days, since I don’t have to be physically active in the morning, I wake up and work for hours at relatively sedentary tasks. I woke up at 8:30 a.m. this morning, did some burpees to wake up my body, and then headed outside to work in a park. I’m currently sitting on a patio at 3:07 p.m. writing this article, and I haven’t had anything to eat. I just sip water all day. I normally break my fast around 3, but since I’m in a groove I want to finish the article before I head home and eat.
This may sound extreme to those who always eat breakfast, but as I’ve explained, your body will adjust the hormone levels that regulate appetite if you consistently restrict your eating window over time. I’m slightly hungry now, but it’s certainly not going to stop me from finishing up my work.
When I go home I’ll eat a big meal, and a few hours later I’ll meet up with a friend to do a workout. Afterwards, I’ll eat another big meal before I start winding down for the night.
When I need to wake up earlier, I usually get hungry earlier in the day, and I might start eating around 12 p.m. or 1 p.m. – it’s totally reasonable to adjust your window’s start time based on your occupation and lifestyle.
What about having breakfast early to shift your eating window into the first part of the day? This is a totally legitimate option, particularly if you tend to work out in the morning. I find I don’t sleep well if I haven’t eaten within a few hours of my bed time, however, so I don’t enjoy this myself. Others seem to thrive on the routine.
How long should your eating period be? When I first started, I was happy if I could contain my eating window to 9 hours, but I’ve seen the best digestive results with 6 hours or less, so that’s what I aim for most days. If I don’t hit this target every day I’m not worried about it. Don’t let it become another stress on your life.
Intermittent Fasting: Putting The Pieces Together:
Intermittent fasting can seem daunting if you’re used to eating from the time you wake to the time your head hits the pillow, but the body is perfectly capable of adjusting to, and thriving on, a more limited eating window. You’ll likely find your digestive system loves it, and your mental clarity is at its peak great during your fasting window.
Consider giving it a shot if you’ve got digestive complaints, but just realize that it’s not the be-all-end-all solution. You’ll probably need to improve your diet as well.