How might intermittent fasting cause constipation? 3 Tips for Preventing

Intermittent fasting is a dieting pattern that is geared at periods of fasting followed by a guided timeframe for which to eat. Studies have shown that intermittent fasting can generate clinically significant weight loss of over five percent^[1], in addition to improving metabolic health.

The bottom line is that intermittent fasting is a great way to lose weight and more adults are starting to incorporate this technique for losing weight. However, one downside to a consistent intermittent fasting lifestyle is that it may cause a reduction in bowel movement activity, or constipation. With that said, the information ahead describes why this phenomenon can happen and tips to reduce the prevalence of constipation.

How Does Intermittent Fasting Cause Constipation?

Dehydration

Intermittent fasting involves periods of fasting with short durations of eating. During the periods of fasting, drinking plain water is allowed, but the concept is to prevent eating food during this time.

There are various ways to perform intermittent fasting, with some programs having as many as 18 hours of fasting and six hours of eating. Depending on your programming, or the hours in which you are fasting, a decrease in fluid status can occur.

The bottom line is that when fluid intake is low, the body is at risk for dehydration, which could lead to fewer bowel movements. In addition, since there is a relative reduction in the total amount of calories consumed, especially from carbohydrates, the risk of dehydration can be more pronounced and lead to bowel problems and less frequent bowel movement habits. The overall reduction in food consumed can decrease the amount of fluid in your body, which can dehydrate your system, which can lead to constipation^[2]. 

Decreased Fiber Intake

Since many people on an intermittent fasting program have a reduced timeframe to consume the day’s energy, fiber consumption could be affected. Foods high in fiber tend to fill you up quickly and full for a long time, so for some, this could be a downside when on the eating portion. In addition, when consuming foods high in fiber, it is necessary to drink enough fluid to prevent constipation in the first place, which should lead to more frequent bowel movements. 

Gut Flora Is Interrupted

Another consideration during intermittent fasting to look out for is how the gut flora can be affected. Many foods naturally contain compounds that help to regulate a healthy gut. When on an intermittent fasting program, some of these foods might be overlooked or just not consumed in adequate amounts, which might lead to fewer bowel movements.

What Might Constipation Feel Like?

Constipation is one of the most common intermittent fasting side effects. If constipation does occur, it could be due to an increase in insoluble fiber and decreased water consumption. Also, it is important to drink three to four liters of water per day to help pass stool with ease.

Tips To Reduce Constipation During Intermittent Fasting 

If you experience any kind of symptoms of constipation when intermittent fasting, finding ways to prevent or reduce the feeling is important. The tips below guide you in your journey to help ease constipation if you experience it at any time.

Drink Sufficient Water

Perhaps the best way to increase the frequency of bowel movements is to drink sufficient water. While there is no perfect formula for how much water you should consume daily, studies have shown^[3] up to two liters per day to be sufficient to increase stool frequency. Consider sipping on water throughout the day and try to drink coffee in moderation.

Eat Adequate Fiber

In addition to having enough water, it is vital to consume adequate amounts of fiber each day while on an intermittent fasting program. A poor dietary fiber intake is common, and many adults do not meet the daily fiber guidelines. Guidelines suggest that adults should get about 22 to 34 grams of fiber^[4] each day. This can be made possible by having sound eating habits that include consuming high fiber foods such as beans, legumes, whole grains, and plentiful vegetables. Consuming enough fiber and increasing fiber consumption can help to increase the number of bowel movements to prevent constipation.

Probiotics

While certain foods help with constipation, probiotics taken as a supplement or with Greek yogurt might have some benefit with constipation. Systematic reviews have demonstrated^[5] benefit on stool transit time, frequency, as well as consistency. In addition, there might be some benefit of consuming probiotics for weight loss. Consider supplementing with probiotics or consuming Greek yogurt to boost overall digestive health and improving digestive tract health so that you can have more bowel movements.

Tips For Intermittent Fasting

In order to have success while performing intermittent fasting, it is wise to know how to be efficient. Consider the tips below to boost your overall success.

• Stay Well Hydrated. It cannot be overly stated, but hydration will play a major role in your intermittent fasting program. Drinking about two liters of water per day is a good goal and consider mixing in electrolytes when possible.
• Increase Your Dietary Fiber Intake. Especially on your last meal of the day, consider increasing your dietary fiber intake to help you remain full. Since adults should aim for a daily dietary fiber consumption of about 22-34 grams daily, the final meal of the day should have roughly 10 grams.
• Nail down your Eating Patterns. To be successful with intermittent fasting, having a sound eating pattern can really make a difference. This means that after you find the fasting period that works for you, the foods you eat should have sufficient calories, nutrients, protein, and fiber.
• Plan Your Workouts Accordingly. It should come as no surprise that there might be times you are hungry following a strenuous workout. If this is something you experience, consider timing your workouts accordingly to help offset this, especially if you exercise in the middle of your fasting hours.
• Time Your Fasting. Consider timing your fasting in ways that don’t seem like you’re starving. For example, if you fast for 12 hours, you can have your last meal by 7 at night. The next time you eat would be 7 the next morning. If you fast for 18 hours, try having your last meal by 5 at night and your first meal the next day at 11 in the morning. Scheduling your fasting period like this can help to reduce the thought that you haven’t had food in a while.
• Be Mindful Of Calorie-Dense Foods. While you need to have enough nutrients, your food intake should not include indulging in ice cream, fatty foods, and other unhealthy options. Consider following a healthy eating lifestyle while in your fasting program and limit your calorie-dense foods to a once-a-week treat.
• Add Flavor With Herbs.  Rather than using fat and cooking oils to prepare your foods, consider utilizing herbs and other non-calorie options to enhance the flavor.

Conclusion

Intermittent fasting can affect the gastrointestinal tract and cause constipation. Following along with the tips above can help guide you along your journey so that constipation does not set in. In addition, consider the tips above on intermittent fasting so that you can be successful in your weight loss and healthy lifestyle journey. 

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