Oral Nutritional Supplements

Oral nutritional supplements can be a powerful tool in the struggle against malnutrition. They provide an easy and concentrated energy source with plenty of much-needed nutrition during the best of times, and the worst of times, when it can be very difficult to consume enough nutrition to maintain a healthy immune system and overall health. This article will discuss some of the various oral nutritional supplements out there, and the pros and cons of each, to help guide you in making a decision for yourself or a loved one. I always advocate for whole food first but, in certain diseases or conditions, when eating enough is not feasible or realistic (e.g., flare up of inflammatory bowel disease, severe malabsorption, short bowel syndrome, oral cancer, dementia, anorexia, or severe and unintentional weight loss), then oral nutritional supplements can be an excellent choice to get in those much-needed calories.

Malnutrition

Experts estimate that even a 10% decrease in caloric intake can weaken the immune system. Working as a dietitian in the hospital, I see a lot of people who consume much less than that. If a healthy adult typically consumes 2,000 calories a day, then this means that eating only 200 fewer calories per day can weaken their immune system. That is the equivalent of one small banana with one and a half tablespoons of peanut butter, not very much when you think about it. The Canadian Malnutrition Task Force reports that up to one in two people admitted to the hospital are malnourished, and suggest using oral nutritional supplements appropriately to prevent and treat malnutrition.¹

Oral Nutritional Supplements

Oral nutritional supplements provide calories, protein, vitamins, and minerals, and they can replace a meal. They may or may not contain additional fibre, omega-3 fats, prebiotics, and probiotics. They are available at almost any grocery store, drug store, or online, and there are many different brands out there, including Boost®, Compleat®, Ensure®, Glucerna®, Isosource®, Premier Protein®, Rumble®, and Soylent®. Many oral nutritional supplements are created to provide 100% of the daily recommended intakes (DRIs) for vitamins and minerals in a volume of 1-1.5 L per day, but remember that the DRIs are meant for a healthy population, and if you have specific health conditions, you may need more vitamins and minerals than those provided in these supplements. Boost® Soothe, for example, has a cooling sensation specifically designed for persons who have sensory alteration or oral discomfort after undergoing chemo or radiation therapy. It is a clear liquid designed without certain ingredients known to have a metallic aftertaste, as this is an issue for individuals who undergo oncology treatments.

Please don’t hesitate to ask your doctor or dietitian about any special nutritional needs, especially if you are relying on oral supplements for the majority of your daily caloric intake.

The calories provided in these drinks tend to range from one to two calories per ml, with the majority of calories coming from carbohydrates. These carbohydrates often come from corn syrup solids, and they tend to taste very sweet, which some people enjoy, but many others do not. Strategies to make these supplements less sweet include drinking them cold with plenty of ice and/or diluting them with milk or milk alternatives, such as oat milk. These drinks can also be warmed up, as some people prefer to drink warm liquids, but it is not recommended to boil them as that can denature the protein and make it less nutritious. You can also add these supplements to various food items, including oatmeal, overnight oats, and chia seed pudding, or frozen into popsicles, if you want to get creative. They can also replace milk in some recipes, such as in soup, muffins, or quick breads like banana or zucchini bread. Manufacturers use a variety of different ingredients in their products, and there are some that have lower amounts of sugar, such as the Canadian-created Rumble®, which is sweetened with maple syrup and provides only 11 g of sugar in one 355 ml bottle, which is less than one tablespoon of sugar. This supplement also does not contain artificial sweeteners, which many other supplements contain, including those created for persons living with diabetes.

The protein sources in oral nutritional supplements can come from dairy (casein or whey), soy, or pea protein. We know that protein is essential for the structure, growth, and maintenance of the cells and tissues in the body, which is especially important during times of increased stress or inflammation, when the body needs even more protein to promote healing. Almost all of these supplements are lactose-free and/or gluten-free, and they may or may not be plant-based. Fat sources in these supplements may come from the following sources: corn, soybean, sunflower, safflower, coconut, palm oil, fish oil, or medium-chain triglyceride (MCT) oil. People who have trouble digesting fat may prefer MCT oil to enhance absorption and optimize tolerance. This could be appropriate for certain conditions including pancreatitis and cholecystitis, which make it more difficult to absorb fat.

Fibre is crucial for gut health and a healthy microbiome, but not all oral nutritional supplements contain fibre. Why? It’s because there are many people with digestive diseases or conditions (e.g., strictures, or recurrent small bowel obstructions), who need to avoid fibre in the short- or long-term. The majority of oral nutritional supplements, including those with added fibre, are still considered to be low fibre and below the recommended amount of 25-38 g of fibre per day.

If you are relying mostly on oral nutritional supplements for your nutritional needs, and you want to get enough fibre in your day, then you will need to consider getting additional fibre from food (vegetables, fruits, legumes, nuts, seeds, whole grains) and/or supplementation (e.g., 100% ground psyllium husk, flaxseeds, chia seeds), instead of relying on oral nutritional supplements to meet the recommended amounts. The fibre sources in oral nutritional supplements can come from soy fibre, guar gum, or inulin, to name a few. If you’re not sure if you should take a supplement with added fibre, please talk to your doctor or dietitian if you want to know if you would benefit from an oral nutritional supplement with fibre, or if you need to consume more from food sources.

Comparing Oral Nutritional Supplements*

*not an exhaustive list of these products

Conclusion

Oral nutritional supplements can be used to prevent and treat malnutrition, with some options out there on the market being healthier than others. I would love to see more natural supplements that are high in protein and healthy fats (e.g., avocado oil, extra virgin olive oil, or flaxseed oil), and low in sugar, especially ultra-processed sugars, and without the need for artificial sweeteners. It would also be great to see more supplements without as much sugar, as this can have a pro-inflammatory effect on the body, which is detrimental for overall health, and I meet many people who simply don’t like very sweet foods and drinks. Sometimes, in the short-term, getting enough calories is more important than where the calories come from. We are lucky to live in Canada where we have so many options to choose from.

Note: Neither the Gastrointestinal Society nor the author have received funding from any of the manufacturers of products mentioned in this article.

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Anne-Marie Stelluti, RD

First published in the Inside Tract® newsletter issue 219 – 2021

1.  Canadian Malnutrition Task Force. Malnutrition Overview page. Available at: https://nutritioncareincanada.ca/about-us/malnutrition-overview. Accessed 2021-07-15.