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Oral Nutrition Supplements: A Tool to Prevent Malnutrition

By Michelle Bratton, RD, CSO January 3, 2023Nutrition Education Services Center Blog

Oral nutritional supplements (ONS) are ready-to-drink or powdered formulas of carbohydrates, protein, fat, vitamins, and minerals. They can be used to supplement someone’s diet with needed calories and protein, or they can be used as an occasional meal replacement. Dietitians and physicians often recommend ONS to people who struggle to meet their daily nutritional needs from food. They can be an effective tool in addressing disease-related malnutrition, a condition in which people with cancer and other chronic disease may not be able to consume adequate nutrients. In fact, it is estimated that 30 to 80% of people with cancer will become malnourished at some point during their cancer experience[1].

There is nothing unique in the kind of nutrients that these products provide, but rather as a liquid, they are a quick and effective way of consuming a good deal of calories and/or protein. While it’s best to get nutrients from whole foods, when possible, a supplement can be an easier way to meet their calorie and protein needs. For example, a peanut butter sandwich on whole wheat bread (2 slices of bread with 1.5 tablespoons of peanut butter) provides approximately 350 calories, the same amount in some ONS, but a person struggling with low appetite, difficulty swallowing, or taste changes may find it easier to sip on a shake than to eat a sandwich.

A homemade shake or smoothie can serve the same purpose as an ONS; however, an ONS can be more convenient for people on the go or who may lack the energy to prepare their own. On the other hand, homemade options allow the person to choose the ingredients and flavors they prefer, and some people do not enjoy the taste or texture of ONS. Another concern is the cost of ONS, since they are often not covered by health insurance plans. To save money, consumers can look for generic versions and/or coupons on the websites of name brand products.

Different ONS provide different nutrients. Some are high in both calories and protein while others may provide high protein (up to 30 grams) with fewer calories (i.e., 160). The lower calorie products usually have less carbohydrates and can be a good option for people who may be meeting their calorie needs but need a protein boost.

Do we know that oral nutritional supplements work? The science suggests they indeed do. Numerous studies show they improve nutrient intake, body weight and functional status, such as muscle strength and the ability to complete activities of daily living. In addition, the studies show a positive benefit in decreasing complications such as infections and a reduction in the need for hospital admissions[2]. Some research suggests that counseling by a registered dietitian nutritionist can be more impactful than the use of ONS[3], [4]. Ideally, patients with cancer have access to both strategies to help optimize their nutrition and health.


1 – Walsh D, Szafranski M, Aktas A, Kadakia K. (2019). Malnutrition in Cancer Care: Time to Address the Elephant in the Room. Jour of Onc Prac, 15(7), 357-359.

2 – Stratton R, & Elia M. (2010). Encouraging appropriate, evidence-based use of oral nutritional supplements. Proceedings of the Nutrition Society, 69(4), 477-487. doi:10.1017/S0029665110001977

3 – Baldwin C, Smith R, Gibbs M, Weekes CE, Emery PW. (2021). Quality of the evidence supporting the role of oral nutritional supplements in the management of malnutrition: an overview of systematic reviews and meta-analyses. Adv Nutr, 12(2), 503-522.

4 – Lee JLC, Leong LP, Lim SL. (2016). Nutrition Intervention Approaches to Reduce Malnutrition in Oncology Patients: a systematic review. Support Care Cancer, 24(1), 469-480.

Michelle Bratton, RD, CSO

Author Michelle Bratton, RD, CSO

Nutrition Educator Michelle has been a Registered Dietitian for 35 years and is a Certified Specialist in Oncology Nutrition. This credential recognizes specialized knowledge in the field of cancer and nutrition. For the past 15 years, she has been the outpatient dietitian at the University of Arizona Cancer Center and has expertise in the nutritional management of patients undergoing chemotherapy, radiation and surgery. She recently joined the PearlPoint Nutrition Services team at The Leukemia and Lymphoma Society (LLS). She counsels patients on ways to maintain good nutrition during treatment and adopting a healthy diet for cancer survivorship. She loves her job and finds working with cancer patients very rewarding. She has published several articles on the topic of nutrition and cancer. In her free time, she enjoys hiking and cooking.

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