Although there is no substantial evidence that diet alone can treat or cure Crohn’s disease or ulcerative colitis, clinical practice and scientific evidence show that proper nutrition and specific dietary changes may help manage many challenges that come along with these inflammatory bowel diseases (IBD).

Amongst these challenges are dietary issues associated with, including: energy and nutrient deficiencies, weight loss, fatigue, and individual food intolerances that may worsen symptoms. In order to address these major issues, dietary management of IBD should be focused on two major areas – symptom management, and meeting energy and nutrient needs.

Symptom Management

The dietary strategies that may be used in conjunction with drug therapy for symptom management of IBD are to avoid or limit foods that trigger symptoms, and to increase foods of benefit to overall health. Dietary intake may change quite a bit when experiencing a flare compared to remission. During a flare, individuals with IBD often find relief by consuming a low fiber diet. Whereas when in remission, it is recommended that high fiber foods are gradually added back in for optimal health. Certain foods that may not cause symptoms during remission may trigger them during a flare. These may include:

  • Carbonated, or “fizzy,” drinks
  • High-fiber foods such as popcorn, vegetable skins, and nuts
  • Fatty foods

One of the challenges with IBD is that there is not one particular diet that works for everyone with the disease. Foods that worsen symptoms for one individual may be very different than foods that worsen symptoms for the next. It is important that each individual with IBD find his/her own specific food intolerances. The first step to pinpointing food intolerances is to record a food and symptom journal. After the first few weeks of doing so, common problem foods may come to light.

In many cases, finding food intolerances is not easy. It may be necessary to try a type of food elimination diet to discover which foods may be aggravating your symptoms. Two of the more successful elimination diets that exist to date for individuals with IBD are the Specific Carbohydrate Diet and the Low FODMAP diet. These diets may provide more success with the help of a physician or registered dietitian specializing in digestive health disorders.

Meeting Energy and Nutrient Needs

Individuals with IBD are at a higher risk of becoming malnourished as a result of a loss of appetite (secondary to symptoms), increased caloric demands of the body due to chronic disease, and poor digestion and absorption of nutrients in the small and large intestines. This can result in worsened feelings of fatigue, weight loss, nutrient deficiencies, and a decrease in overall health. To prevent this, it is important to focus on preventing malnutrition with a healthy and balanced diet. Some patients need to be more careful, making sure to eat small and frequent meals and snacks every 2-3 hours and monitor blood levels of nutrients at risk using supplements when necessary.

Malnutrition in Crohn’s Disease

Malnutrition occurs when the body is lacking nutrients – from suboptimal intake through diet, from malabsorption or loss of nutrients in the gastrointestinal tract. When malnutrition occurs, common side effects are rapid or unintentional weight loss, and worsening fatigue. There are a few reasons individuals with Crohn’s disease are at a higher risk of malnutrition. For one, it is common to experience a loss of appetite with the disease whether it comes from a general sense of feeling unwell during a flare, or a fear that eating anything will worsen symptoms. This decrease in appetite often leads to a decrease in food intake. Another common issue with Crohn’s disease is that individuals may have a variety of food intolerances that greatly restrict usual intake. Other factors that may put patients with the disease at risk for malnutrition include increased nutrient and caloric requirements from the state of chronic disease itself, side effects of medications, and malabsorption of nutrients – especially when inflammation is present.

Effects of Crohn’s Disease on Digestion

It is important to first understand the general process of digestion before realizing the effects of Crohn’s disease on nutrient digestion and absorption. Digestion can be defined as the process of food being converted into substances that can be absorbed by the body.

The body absorbs nutrients from food in order to function properly. Most absorption of nutrients occurs in the duodenum and jejunum, the first two portions of the small intestine, with the exception of vitamin B12 which is absorbed in the ileum. Watery food residue and undigested secretions pass into the large intestine, or colon, where water is recycled. Solid, undigested food mixes with bacteria living in the large intestine to form bowel movements. In Crohn’s disease, the inflamed small intestine is less able to properly digest and absorb nutrients, and these partially digested foods then travel to the colon where they may cause diarrhea. Nutrient deficiencies may occur from inability for nutrients to be absorbed into an inflamed small intestine, or from increased losses with bowel movements.

Nutrients at Risk with Crohn’s Disease

There are many nutrients at risk of deficiency with Crohn’s especially when there’s a decrease in food intake. However, certain nutrients are at a higher risk of deficiency. Which nutrients at risk also depend on the area of the small intestine that is affected. The two macronutrients at largest risk of deficiency are protein and fat. Bowel protein loss is correlated to the extent of intestinal inflammation – when more inflammation is present there are more protein losses from the bowel, and extra attention should be placed getting enough protein in the diet. Fat malabsorption occurs in some individuals with Crohn’s disease.

At particular risk are those who have had a long terminal ileal resection (greater than 1 meter). If fat malabsorption is an issue, the fat-soluble vitamins A, D, E, and K are also at risk of deficiency. Vitamin B12 may be at risk if the disease affects the ileum or for those who have had a portion of the ileum resected, as vitamin B12 is absorbed in the terminal ileum. For these individuals, a physician will likely prescribe vitamin B12 injections.

Additionally, folate may be at risk when being treated with methotrexate and sulphasalazine as they specifically increase folate requirements. Calcium and vitamin D are also at risk when using steroids over a prolonged period of time, and possibly from decreased intake if lactose intolerance is an issue. Minerals at risk include iron, zinc and magnesium – primarily due to inflammation in the intestines and losses from chronic diarrhea.

Below is a chart summarizing nutrients at a higher risk of deficiency with Crohn’s disease, and dietary sources of these nutrients:

Popular Diets for Crohn’s Disease and Ulcerative Colitis

As previously discussed, diet can play a major role in the management of Crohn’s disease and ulcerative colitis. With so much information currently accessible to us, it can be difficult to filter through diet trends that you might hear or read about. The following summarizes the most popular diets out there that have claimed to help others with Crohn’s and colitis, and highlights which ones may be more worthwhile to try under the guidance of a registered dietitian or physician.

1. The Specific Carbohydrate Diet (SCD / Breaking the Vicious Cycle)

This diet was first developed by Dr. Sidney Haas as a way to treat celiac disease. It was made more popular for the treatment of Crohn’s disease and ulcerative colitis by biochemist Elaine Gottchall through her book Breaking the Vicious Cycle.

Diet Summary & Claims:

The Specific Carbohydrate Diet limits most carbohydrates from the diet except for monosaccharides (glucose, fructose, and galactose), with the rationale being the single molecule structure of monosaccharides allows them to be easily absorbed into the intestine wall. The diet proposes that complex carbohydrates are not easily digested and therefore feed harmful bacteria in our digestive tract causing them to overgrow producing by products and inflaming intestine wall. The goal of the diet is to “starve out” harmful bacteria and restore the balance of bacteria in our gut (Gottschall, 2012).

Research Available:

While limited research currently exists for the Specific Carbohydrate Diet and its use in the management of Crohn’s disease and ulcerative colitis, preliminary evidence suggests SCD may help control symptoms and inflammation in a pediatric population with Crohn’s disease and ulcerative colitis when adopted in conjunction with medical therapy (Chinonyelum, 2015).

Dietitian Recommended?

Due to promising results from preliminary research with the Specific Carbohydrate Diet in children with Crohn’s or colitis, this diet may be worth trying when other dietary options have been exhausted. It is recommended to follow the guidance of a registered dietitian for support as this diet can put individuals at a higher risk for nutrient deficiencies.

2. The Low FODMAP Diet

This diet was developed by gastroenterologist Dr. Peter Gibson and registered dietitian Dr. Sue Shepherd. It was intended to decrease functional gut symptoms such as gas, bloating, distention and diarrhea and/or constipation commonly seen in people with irritable bowel syndrome.

Diet Summary & Claims:

FODMAP stands for fermentable oligosaccharides, disaccharides, monosaccharides, and polyols – which are all different types of short chain carbohydrates that are poorly digested in the small intestine and increase small intestinal water content or are rapidly fermented by gut bacteria that naturally reside in the large intestine, resulting in symptoms such as gas, bloating, diarrhea and/or constipation. The low FODMAP diet eliminates foods that are high in short chain carbohydrates in order to decrease symptoms.

Research Available:

There is substantial scientific evidence to show the low FODMAP diet improves symptoms in 75% of patients with irritable bowel syndrome (Gibson, 2010). A pilot study revealed an improvement in functional gut symptoms when patients with stable Crohn’s or colitis adhered to the low FODMAP diet (Gearry, 2009). A subsequent study also demonstrated an increase in the relief of functional gut symptoms and reduction in symptom severity among IBD patients who followed the low FODMAP diet as delivered by a team of registered dietitians (Prince, 2009).

Dietitian Recommended?

The low FODMAP diet is strongly recommended for patients with Crohn’s disease or ulcerative colitis who also experience gas, bloating, distention and diarrhea. However, it will not treat inflammation that comes with the disease, and therefore is not recommended to replace medical treatments but instead used in conjunction with medical treatments prescribed by your physician.

3. The Paleo Diet

This diet was introduced by a gastroenterologist, Dr. Walter L. Voeglin. It has been made more popular by Dr. Loren Cordain and was initially designed to optimize health, minimize risk for chronic disease, and achieve weight loss.

Diet Summary & Claims:

The theory behind the Paleo diet is that the digestive tract is not able to handle foods in our diet that resulted from modern agricultural methods, and that these foods result in modern diseases. This diet emphasizes intake of lean meats and plant-based foods, and to avoid consumption of grains and legumes (Eaton, 1985). A large portion of energy intake is supposed to come from protein and fat instead of carbohydrates as a major energy source. The Paleo diet is based on assumptions of our evolution, and therefore, has no specific claims about the effect of this diet on Crohn’s or colitis.

Research Available:

There have been no scientific studies done on the benefits of the Paleo diet for the management of Crohn’s disease and ulcerative colitis.

Dietitian Recommended?

The Paleo diet is not recommended as there is no scientific evidence supporting its use for managing Crohn’s and colitis as there are major restrictions placed on dietary intake that may result in nutrient deficiencies, low energy intake, and further weight loss. Due to the emphasis on animal protein and fat in this diet, it also puts individuals with Crohn’s or colitis at risk of developing further health conditions in the long term such as high cholesterol, high blood pressure, and cardiovascular disease or stroke.

A proper diet can help prevent malnutrition and avoid nutrient deficiencies. Eating well will improve energy levels, help with symptom management, enhance immunity and the body’s ability to heal, and improve overall quality of life. It is important to focus on meeting energy and nutrient needs as individuals with Crohn’s disease are at risk of becoming malnourished.

Considerations for Athletes

Being active with IBD has many health benefits and can improve your overall quality of life. If you live an active lifestyle with Crohn’s disease or ulcerative colitis – whether that means going to the gym a few times a week, being a “weekend warrior”, or being an elite athlete; it can be challenging to fuel for your activities while sticking to foods that are suitable for your digestion.

There are a few key points to consider as an athlete or active individual living with IBD:

  • It’s important to meet energy and nutrient needs, which are elevated when participating in sport and exercise.
  • Regular exercise can contribute to further inflammation; it’s important to eat foods high in anti-oxidants and protein.
  • Time your meals and snacks around workouts & activities each day for optimal energy during workouts and effective recovery afterwards.
  • Stick to eating “safe foods” that you know won’t trigger symptoms throughout the day and during activities.

These points will be discussed with some practical recommendations below.

1. Meeting energy and nutrient needs

How much extra energy you need from food depends on the type and amount of activity you’re doing, as well as any specific goals you have. As you increase the amount of activity in your day, or participate in more intense training, you may want to eat more calorie-dense foods and protein – eating equal amounts of grains/root vegetables, high protein foods, and vegetables & fruit. Your plate may look like this:

Grains include rice, pasta, breads; root vegetables include potatoes, yams, sweet potatoes & squash. Protein foods include lean meats and fish, legumes (beans, lentils, chickpeas), and dairy products such as milk, yogurt, and cheese. Be sure to add healthy fats such as olive oil, avocado, nuts and seeds with your meals and/or snacks throughout the day.

Aim to have snacks between your meals as well to help you meet your energy and nutrient needs. Combine ‘ENERGY foods’ with ‘SUSTAIN & REPAIR foods’. Try to include ‘PROTECTION foods’ (vegetables/fruit) with all snacks*.

Note: “carbohydrate foods” also include vegetables & fruit. If you’re less active, stick to vegetables/fruit + protein as a snack. If you’re more active and/or struggle to keep on weight, add a grain or root vegetable with that.

Ask your doctor about getting blood tests more often as an athlete or active individual with IBD. Nutrients of particular concern include iron, vitamin B12, folate, and vitamin D.

2. Eat foods that help fight inflammation

While there are many health benefits associated with regular exercise, high-intensity training can also contribute to inflammation in the body. You can counteract this by eating more foods that are high in antioxidants and healthy fats (omega 3’s).

Aim to have more of the following foods each day:

  • Bright coloured vegetables and fruit. Aim to have at least one serving of dark leafy greens AND one serving of orange vegetables or fruit
  • Green tea
  • Dark chocolate (>70% cocoa)
  • Turmeric tea or juice
  • Tart cherry juice (1 oz. before and after each workout, if tolerated)
  • Fatty fish (salmon, tuna, mackerel, sardines), chia/flax seeds, walnuts, olive oil

With Crohn’s and ulcerative colitis, protein needs are already elevated. Add regular exercise into the mix, and your protein needs are even higher. Aim to consume protein with every meal and snack throughout the day.

3. Timing of meals & snacks to optimize energy and facilitate recovery

What to eat before your workouts depends on when you eat in relation to your workout. See the chart below to help determine what to eat depending on when you train.

Recovery is an essential component of any exercise or training program. Make sure you refuel with carbohydrates and protein within 30 minutes after training to replenish energy used during today’s session, preparing you for tomorrow’s session AND to stop muscle breakdown and start muscle building. Examples of good recovery foods include: chocolate milk or soy milk, a fruit & yogurt smoothie, or a meal following the plate rule mentioned above.

4. Keep symptoms and energy levels under control

While there are certain things in sport nutrition that are important for optimal energy, fueling and recovery – it’s important that you still stick to safe foods that you know won’t trigger symptoms. For example, sport nutrition products such as energy drinks & bars may be convenient, but can often be high in sugar and other ingredients that you don’t digest well.

Consider keeping a food, exercise, and symptoms log to help you to identify which foods you feel the best on, and which foods you may want to avoid before a workout if they trigger any symptoms. Take note of your energy levels as well to help you determine a workout program and diet that doesn’t contribute to more fatigue.

Sample Food, Exercise & Symptoms Log:

As with anyone participating in a new training program, make sure you listen to your body. If you feel more fatigued than usual –lower the intensity of your workouts or take a day off. Prioritize your recovery. In addition to eating after each workout, make sure you get adequate sleep, stay well hydrated, and eat more foods with lots of antioxidants.

Superfoods for Crohn’s Disease and Ulcerative Colitis

Many patients with inflammatory bowel disease (IBD) are curious about certain superfoods that are popular in the media. It’s important to know that what may be well tolerated and digested by the general public may not actually be the same for individuals with Crohn’s disease or ulcerative colitis. This may depend on how much inflammation is present and whether the individual is in remission or experiencing a flare. For example, kale is a really healthy food, it’s high in antioxidants. But it’s also high in insoluble fiber. So if an individual is having a flare, kale may make symptoms worse.

1. Gottschall, E. Breaking the vicious cycle: intestinal health through diet. Kirkton, Baltimore. 2012.
2. Obih, Chinonyelum, et al. “Specific carbohydrate diet for pediatric inflammatory bowel disease in clinical practice within an academic IBD center.” Nutrition 32.4 (2016): 418-425.
*3. Gibson PR, Shepherd SJ. Evidence-based dietary management of functional gastrointestinal symptoms: The FODMAP approach. J of Gastroenterol and Hepatology. 25 (2): 252-258, 2010.
4. Gearry RB, Irving PM, Barett JS, Nathan DM, Shepherd SJ, Gibson PR. Reduction of poorly absorbed short-chain carbohydrates (FODMAPs) improves abdominal symptoms in patients with inflammatory bowel disease-a pilot study. J Crohns Colitis. 3 (1): 8-14, 2009.
4. Prince, Alexis C., et al. “Fermentable carbohydrate restriction (low FODMAP diet) in clinical practice improves functional gastrointestinal symptoms in patients with inflammatory bowel disease.” Inflammatory bowel diseases 22.5 (2016): 1129-1136.
*5. Eaton SB, Konner M. Paleothilic nutrition. A consideration of its nature and current implications. N Engl J Med. 31: 283-289, 1985.