Can malnutrition occur even without a swallowing disorder?

Some people with ALS experience unintended weight loss even without swallowing difficulties. This group of patients has an ALS-associated metabolic disorder that is associated with an increased energy requirement (“resting metabolic rate”). This ALS-related weight loss parallels other “wasting” diseases (e.g., cancers) that lead to the depletion of fat reserves and a loss of muscle mass (known as “primary wasting” syndrome).

In other ALS patients, weight loss may result from certain ALS symptoms (“secondary wasting syndrome”). For example, some patients experience weakness in the trunk and diaphragm muscles early in the course of the disease (axial ALS), which is associated with respiratory weakness, increased respiratory effort, and heightened energy requirements. The negative energy balance can be exacerbated if, in addition to the increased energy requirements, food intake is reduced. A common cause is a loss of appetite, which can be due to various factors (stress, depression, constipation). Motor impairment in the arms can contribute to reduced food intake by limiting the ability to use utensils, prepare food, and perform eating movements.