Crohn’s is a relatively common disease. One of the most annoying aspects of Crohn’s is that it interferes with your diet. Eating certain foods can trigger your symptoms, which prevents you from eating a well-balanced diet. The result? Malnutrition and weight loss.

If you have Crohn’s and are struggling to maintain a healthy weight, here are some ideas to help you out.

What is Crohn’s disease?

Crohn’s disease is an autoimmune condition that mainly affects your intestines. For unknown reasons, the body attacks itself, leading to inflammation and swelling of the gut. The most common site of Crohn’s disease is the terminal ileum, which is the last part of your small intestine. However, the disease can affect any part of the GI tract from your mouth to the anus.

If you have Crohn’s, you may experience:

• Long-term, non-bloody diarrhea
• Abdominal pain, particularly in the right lower quadrant because that’s where the ileum lies
• Nausea
• Vomiting
• Fever
• Weight loss
• Fatigue

Inflammation in Crohn’s is not always limited to the intestines, which is why you may experience the following extraintestinal symptoms as well:

• Painful joints
• Inflamed eye
• Renal stones
• Skin rashes
• Liver disease

Can Crohn’s make me skinny?

Yes, Crohn’s can make you skinny if severe. There are two main reasons for this. First, many foods seem to trigger Crohn’s symptoms, and this may lead to avoidance of a well-balanced diet. You should note, however, that no foods have been scientifically proven to cause the disease.

And second, if your Crohn’s is severe, it may hamper the ability of your gut to absorb nutrients properly. Crohn’s usually affects the terminal ileum, which is where the body absorbs vitamin B12. Vitamin B12 is necessary for cell growth and division, and a deficiency may lead to stunted growth in children.

The terminal ileum also absorbs fats. When this area malfunctions, you can develop fat malabsorption, which manifests as steatorrhea. Steatorrhea is basically diarrhea that’s foul-smelling and difficult to wash away. As your body loses fat, it may start burning endogenous fat stores, leading to weight loss.

When you develop steatorrhea, you also lose the ability to absorb vitamins A, D, E, and K. These are fat-soluble vitamins, and their deficiencies can lead to worrisome symptoms. Vitamin D is necessary for healthy bones, and if you become severely deficient in it, you may develop a condition called osteomalacia. The bones lose their strength in osteomalacia, and this may manifest as weight loss in addition to fractures from minor trauma.

The small intestine is also the site of protein (and carbohydrate) absorption. Proteins are particularly important for maintaining a healthy weight, so if Crohn’s significantly reduces your ability to absorb them, you could become skinnier.

Another reason for weight loss in Crohn’s is chronic inflammation. Crohn’s is a long-term condition, and your body is continuously exposed to inflammatory molecules that could lead to muscle wasting and weight loss.

Finally, some people with Crohn’s need to undergo surgery, where the surgeon removes a part of their bowel. This can lead to a reduced ability to absorb nutrients and weight loss.

How can I gain weight with Crohn’s?

To gain weight with Crohn’s, you’ll have to modify your eating habits, add certain food items to your diet, and exclude other items (that seem to trigger your symptoms). You may also need to ask your doctor for vitamin and mineral supplementation (especially vitamin D).

So let’s take a look at what to avoid and what to eat in Crohn’s, as well as how to eat with the condition.

Foods to avoid in Crohn’s disease

During a flare, you must avoid high-fiber foods. While fiber is great for gut health under normal circumstances, it can make a Crohn’s flare worse. Here’s a list of high-fiber foods that you should avoid:

• Cauliflower
• Broccoli
• Other green veggies with a peel
• Whole grain bread
• Whole nuts
• Whole grains
• Fruits with skins
• Barley
• Rye
• Whole wheat pasta

Then, many patients with Crohn’s also suffer from lactose intolerance. If you’re lactose-intolerant, you may experience cramping, bloating, and tummy pain after consuming dairy products such as milk, cheese, and cream, so it’s best to avoid these too.  

Other foods to avoid include: 

• Desserts — or anything with too much sugar
• Caffeine
• High-fat foods like butter and margarine
• Alcohol
• Spicy foods

Foods to eat in Crohn’s disease

What you should eat primarily depends on whether you’re in remission or your disease is active.

During a flare, here’s a list of items you can try to prevent malnutrition:

• Low-fiber items like bananas, cooked fruits, white rice, oatmeal, and potato
• Protein with low fat content — eggs, peanut butter, tofu, and fish
• Milk and yoghurt derived from plant sources like soy
• Protein shakes

You’d want to eat the same diet during a remission, with the only change being a shift towards a high-fiber diet. Research has shown that a high-fiber diet can actually reduce your chances of getting a Crohn’s flare. So make sure to include whole grains, beans, barley, and a lot of fruits and vegetables to your diet. Calcium-rich foods and lean protein will also be essential in maintaining a healthy weight.

You should also ask your doctor about a daily multivitamin, which can help you reclaim lost energy. As mentioned earlier, Crohn’s can lead to a wide range of nutritional deficiencies, and if you’ve been feeling fatigued lately, this may be the reason.

How to eat with Crohn’s

Knowing how to eat is as important as knowing what to eat with Crohn’s. Crohn’s patients can feel full after eating just a bit of food, which is an important cause of insufficient calorie intake. This is why experts recommend eating 5 or 6 times a day instead of thrice. You may reduce the serving size of each meal but you must compensate for this by increasing meal frequency to achieve a healthy weight.

Finally, maintaining a food diary can be very helpful in gaining weight when you have Crohn’s. A food diary will not only allow you to identify trigger foods, but it can also be used by your doctors (or dietitian) to determine whether you are getting enough calories and make appropriate changes to your diet plan!

Medically Reviewed by Onikepe Adegbola, MD PhD