What Is Malnutrition?

Malnutrition is undernutrition, or not having enough nutrients (energy and protein) required for healthy body function. It can result from poor intake or poor uptake of nutrients, or both. Intake refers to getting nutrients into the body, for example, through eating and drinking. Uptake refers to how the body uses and stores the nutrients once they are inside the body. Approximately 7 out of 10 people with cancer develop malnutrition. It is more common and more severe among older people with cancer, and those with stomach, head and neck, and lung cancers.

What Does Malnutrition Lead to?

Malnutrition can cause loss of muscle (called low muscle mass or myopenia), and loss of weight (called cachexia).

Low muscle mass is a central feature of cancer, affecting 4 out of 10 people. Malnutrition, low levels of physical activity, general cancer effects and cancer treatment can all contribute to low muscle mass.

Cachexia is unintentional weight loss and is also known as cancer-associated malnutrition. It affects up to 8 out of 10 people with cancer. It is characterized by loss of appetite and general body inflammation, which create the wrong balance between energy and protein, leading to dangerous weight loss and muscle wasting. Cachexia can be with or without fat loss, and is not a good type of weight loss. Therefore, if it happens to people with a too-high weight before cancer diagnosis this is just as big a problem as it is for people of a healthy or too-low weight. Cachexia cannot be fully reversed by standard nutrition treatments and can worsen with cancer treatment.

How Do Low Muscle Mass and Cachexia Cause Problems for Cancer Care?

These conditions can occur once cancer starts but before it is diagnosed, as well as during or after treatment. If untreated, they are associated with reduced daily life physical ability, reduced quality of life, reduced ability to tolerate cancer medicines (and therefore receive effective treatment), increased risk of complications with surgical treatment, and reduced survival.

In addition, they strain healthcare and economic resources, extending hospital length of stay and increasing the risk of unplanned hospital stays.

What Did the Panel of Experts Recommend?

• Firstly, the panel stressed the importance of healthcare workers from all professions working together for nutrition care in people with cancer (multidisciplinary care). They reported the need to build nutrition care in every layer and stage of cancer care, making it something that all healthcare professionals are involved with. The paper gives examples of scientific studies that show a positive connection between multidisciplinary nutrition care and better cancer care outcomes.
• Secondly, the panel of experts listed principles for nutritional care during cancer treatment. These covered the importance of testing for problems and how best to treat identified problems.

How Do We Test for Malnutrition and Low Muscle Mass?

When? Throughout the cancer care journey. All clinical nutrition societies and several cancer societies recommend screening for malnutrition risk at diagnosis and during and after treatment.

How? Body measurements can be made and compared during the cancer journey. Several scientific assessments are available; however, many have not been fully explored in terms of how they work for people with cancer. Scientists and researchers are currently working on developing assessments that are directly suitable for people with cancer.

How Is Malnutrition Treated?

As soon as a problem is detected, even if it is small, the cancer care team should give additional energy and protein to improve nutrition and prevent serious problems. The cancer care team should use the person’s weight to calculate how much to prescribe. Additional nutrition can be through eating or drinking special supplements, through feeding tubes that go direct to the stomach or bowel, or infusions that go directly into the blood. Each individual should also receive education and advice, according to their specific situation.

The paper gives examples of scientific studies that show that nutrition therapy improves things such as a person’s weight status, ability to tolerate cancer treatment, and survival of cancer.

Why Is Exercise Also Important?

Exercise during cancer treatments preserves or improves a person’s fitness, muscle mass and strength. In turn, this preserves or improves quality of life during cancer treatment and treatment results. Exercise includes general fitness as well as muscle strength training. In fact, exercise recommendations for most people with cancer are similar to those for healthy adults. Of course, care must be taken to support the additional energy needs of those with malnutrition or who have some particular cancers or conditions (for example, bone cancer). Specifically, it has been found that exercise before cancer surgery or a course of cancer medicine is safe and actually helps to improve results.

For people with cancer, the experts recommend:

• 150 minutes per week of moderate to vigorous fitness exercise (more than 2 hours, but not all in one session).
• At least two sessions a week of muscle strength training.

Take-Home Message

People with cancer, and healthcare professionals treating people with cancer, should at every stage of the cancer journey be considering nutrition and checking for problems. It is best to prevent nutrition problems, or treat them early, rather than deal with complications at a later stage. Because nutrition has an impact on muscle health, it is important for people with cancer to carry out regular fitness and muscle strength training. Worldwide, societies are building nutrition care principles into their standard cancer care recommendations and treatment plans.

Note: The authors of this paper make a declaration about honoraria, paid consultancy, and/or funding received from companies. Two of the authors are employed by a company focusing on nutrition. It is normal for authors to declare this in case it might be perceived as a conflict of interest.