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By Janis Jibrin, MS, RD

How to Overcome Obstacles to Weight Gain

Weight loss is a serious problem for some people with neurologic disorders such as Parkinson's disease, amyotrophic lateral sclerosis (ALS), Alzheimer's disease, Huntington's disease, and stroke, says Nikolaus McFarland, MD, PhD, FAAN, chief of the movement disorders division in the department of neurology at the University of Florida College of Medicine in Gainesville.

Illustration by Maria Hergueta

In a 2015 study published in PLOS One, Dr. McFarland and colleagues found that declining weight was linked to lower quality of life. At a healthy weight, he says, patients tend to have more energy and strength. "They also may have better balance and sensory perception, making them less likely to fall." The reasons for weight loss are manifold, he says. The disease itself, medication side effects, changes in activity, taste, and even mood can suppress appetite. Some patients also have trouble chewing and swallowing.

Dyskinesia, or involuntary movements associated with Parkinson's disease, can cause patients to burn extra calories, says Dr. McFarland. The same is true for the restlessness and agitation associated with dementia and Alzheimer's disease. "Even when you're not moving, changes in the brain, particularly the brainstem and hypothalamus, can raise resting metabolic rate. It's as if you turned up the thermostat and now your body burns more calories," he says.

To address weight loss, talk to your physician, advises Sabrina Sitkoski, a registered dietitian and assistant director and clinical nutrition manager at Shirley Ryan AbilityLab, a rehabilitation center in Chicago. "Your health care provider can help investigate your specific problem so you can address it appropriately," she says.

Here are five common obstacles to maintaining a healthy weight and strategies to counter them.

  1. Medication side effects. Nausea from drugs such as levodopa for Parkinson's disease and donepezil (Aricept) for Alzheimer's disease can decrease appetite.

    Solutions: "Talk to your doctor about switching to another drug that doesn't cause nausea or taking medication with food," advises Dr. McFarland.

        1. Tongue and swallowing problems. Swallowing difficulties are often due to damage in areas of the brain—the cortex, subcortical regions, and brainstem—that coordinate the chewing and swallowing responses and nerves in the mouth and esophagus, says Dr. McFarland. The tongue may also become weak, especially in Parkinson's disease, which makes swallowing more difficult, according to a 2018 study published in the Journal of Speech, Language, and Hearing Research. Patients may have trouble keeping food or liquids down, which can cause choking or aspiration—food or drink getting into the lungs—and that can lead to pneumonia.

          Solutions: "Tell your doctor if you're coughing or choking on foods or liquids," says Dr. McFarland. "He or she may refer you to a speech therapist, who can recommend exercises to improve swallowing. If appropriate, discuss dietary changes [with your doctor] such as eating soft foods and thickened liquids."

        2. Diminished taste and smell. "A sense of smell can take a hit with conditions like dementia and Parkinson's," says Ronald DeVere, MD, FAAN, director of the Taste and Smells Disorder Clinic in Austin, TX. Damage to nerves in the nose and the olfactory bulb in the brain can impair your ability to recognize flavors, he says. Many patients with neurologic conditions take medication to control high blood pressure, and these drugs as well as levodopa can dull your sense of taste and smell.

          Solutions: "If your sense of smell is poor, focus on foods with vivid sweet, sour, and salty tastes and enhance the savory taste of meats with seasoning salts," says Dr. DeVere. He also recommends using spices to make food more appealing. "If your taste receptors are dulled, amp up flavors by adding artificial sweetener or flavor extracts like vanilla to oatmeal, shakes, and milk," he suggests.

        3. Delayed gastric emptying. This symptom, common in Parkinson's disease and ALS, means food stays in your stomach longer than it should. The vagus nerve, which runs from the brain to the digestive tract and is stimulated by the neurotransmitter dopamine, helps signal the stomach to empty. In Parkinson's disease, levels of dopamine are lower, so the brain is not getting that signal. "In ALS, the nerves that control the way the stomach empties and how food is moved along the intestine can be affected," says Terry D. Heiman-Patterson, MD, professor of neurology and director of the MDA ALS Center of Hope and the Center for Neurodegenerative Diseases at Temple University Lewis Katz School of Medicine in Philadelphia. She notes that ALS medications used to control drooling can also slow activity in the gastrointestinal (GI) tract. Other factors include poor hydration, trouble swallowing, and immobility.

          Solutions: "Eating six small meals throughout the day instead of fewer large meals creates less work for your stomach," says Dr. Heiman-Patterson.

        4. Constipation. People with central nervous system diseases or injuries are at higher risk of constipation than the general population, says Dr. Heiman-Patterson. As with delayed gastric emptying, both faulty signaling from the brain to the intestinal tract and damage to the nerves of the GI tract are to blame. In addition, immobility and certain medications used to manage the disease or pain can raise the risk of constipation, she says.

          Solutions: Sitkoski suggests trying to consume more fiber. "Eat at least 10 to 12 servings of fruits and vegetables daily and legumes three to four times a week. Also, drink more water or other fluids," she says. "If you're still constipated, over-the-counter fiber supplements can help, especially if you're taking a medication known to cause irregularity." Staying active and exercising may also alleviate constipation. If it persists, talk to your doctor about stool softeners, laxatives, and enemas, says Sitkoski.

    Smart Ways to Eat More

    For people who struggle to maintain a healthy weight because of a neurologic condition, loss of appetite can quickly lead to malnutrition, says Sabrina Sitkoski, a registered dietitian and assistant director and clinical nutrition manager at Shirley Ryan AbilityLab, a rehabilitation center in Chicago. To keep your weight out of the danger zone, consider these tips.

        • Bump Up the Calories. Snack on high-calorie foods such as nuts, granola bars, and shakes like Ensure and Boost, which have 350 to 360 calories per eight ounces, says Sitkoski. If you have a diminished sense of smell, experiment with flavors, texture, and temperature, says Ronald DeVere, MD, FAAN, director of the Taste and Smells Disorder Clinic in Austin, TX.
        • Make Your Own Shakes. For patients who really struggle to keep on weight, Sitkoski created her own high-calorie shake. "It has half chocolate milk and half heavy cream," she says. "It's about 475 calories per eight ounces."
        • Ask About Stimulants. Talk to your doctor about appetite stimulants such as mirtazapine (Remeron) or megestrol acetate (Megace), suggests Nikolaus McFarland, MD, PhD, FAAN, professor of neurology at the University of Florida College of Medicine in Gainesville.
        • Be Persistent. "Don't give up," says Sitkoski. "Eating more can be difficult, but the benefits are worth it."

    Web Extra

    For more about maintaining a healthy weight, go to For three healthy high-calorie recipes, visit They were created by Linda Monastra, a recipe developer and graduate of the Natural Gourmet Institute in New York City, with registered dietitian Janis Jibrin.