Advanced PD and Weight Loss: Causes and Treatment


People with Parkinson’s disease (PD) can lose a considerable amount of weight in the later stages of the disease. This may be due to a combination of factors, including low appetite and high energy expenditure.

Weight loss is a common symptom of PD. However, the American Parkinson’s Association (APDA) emphasizes the importance of first eliminating all potential underlying causes of weight loss.

This is because weight loss can be the result of many medical conditions, so it is not always due to PD.

This article examines the link between advanced stage Parkinson’s disease and weight loss. It also examines why weight loss may occur, when to contact a doctor, and the treatment options available.

Evidence indicates that weight loss is a symptom that people have reported in all stages of Parkinson’s disease.

Research from 2017 suggests that, on average, people with PD may experience mild to moderate weight loss in the first 6 years after diagnosis. However, a person’s weight loss is likely to become greater as the disease progresses.

Additional reports indicate that many people lose weight in the years before their diagnosis of PD. The authors also note that the duration and severity of PD may further increase symptoms of weight loss.

This suggests that although weight loss can occur at any stage of Parkinson’s disease, it may be greater or more severe in the later stages of the disease.

As with other stages of PD, weight loss in advanced PD can be due to a combination of factors. These to understand:

Weak appetite

In late stage Parkinson’s disease, a person may develop a poor appetite due to the following:

  • Decreased sense of smell: About 80-96% of people with PD have an olfactory deficiency that affects their sense of smell. The sense of smell plays an essential role in the attraction of food and the perception of taste. Those with a poor sense of smell may find food less appealing, which can affect their appetite.
  • Depression and other mood disorders: Depression, which can lead to decreased appetite, affects around 35% of people with PD. People with PD may also experience apathy, which is a state of emotional indifference. This is a common symptom of Parkinson’s disease, which can lead to decreased interest in eating or preparing meals.
  • Nausea: Many people with PD may experience nausea and vomiting as side effects of certain PD medications. Nausea can reduce a person’s appetite.

High energy expenditure

Several involuntary movements associated with PD, such as tremors, dyskinesia and rigidity, can increase energy expenditure and promote weight loss:

  • Tremor: Tremor is an uncontrollable rhythmic muscle contraction in one or more parts of the body, resulting in high energy consumption and, potentially, excessive weight loss. At the onset of PD, the first symptom may be a barely perceptible tremor in one hand. Over time, the symptoms get worse and gradually spread to other parts of the body.
  • Dyskinesia: Dyskinesia refers to involuntary muscle movements. Frequent, involuntary physical exertion such as dyskinesia can burn more calories for someone with PD and make it difficult to gain or maintain weight.
  • Rigidity: People with PD may experience involuntary stiffness and tightness in the muscles of the arms, legs, neck, and back. These symptoms can even affect the face. Tight, rigid muscles can increase the body’s energy expenditure.

Gastrointestinal problems

People with PD may lose weight due to gastrointestinal problems that prevent the body from absorbing and using enough nutrients:

  • Constipation: A person can suffer from constipation if they have less than three bowel movements per week. It is one of the most common gastrointestinal symptoms, affecting between 24.6% and 63% of people with PD. This may be due to malnutrition or the slow movement of digestive waste through the colon.
  • Dysphagia, or difficulty swallowing: People with dysphagia have difficulty swallowing certain foods or liquids. Some people are unable to swallow at all. Although health experts consider dysphasia to be a late complication, it can sometimes develop early in PD. The inability to swallow can lead to low food intake, leading to weight loss.
  • Gastroparesis: This partial paralysis of the stomach muscles affects the normal movement of food from the stomach to the small intestine. It can affect 70-100% of people with PD and can occur in early or late stages of PD. Gastroparesis can cause other gastrointestinal issues, including nausea, bloating, vomiting, and abdominal discomfort, which can also contribute to weight loss.

The APDA notes that weight loss may be a sign that the disease is progressing. For example, it could be the result of difficulty swallowing, impaired mobility, and impaired bowel function.

Weight loss can also lead to malnutrition and vitamin deficiencies. As a result, a person may be more likely to:

People who are underweight have an increased risk of osteoporosis or brittle bones. This can mean that bones are more likely to fracture if a person falls.

Weight loss and malnutrition can influence the progression of PD. According to a study in Frontiers of the neurosciences of agingthis weight loss and malnutrition can lead to:

  • involuntary muscle movements
  • cognitive decline
  • orthostatic hypotension, which is a type of low blood pressure that occurs when a person stands up from sitting or lying down

If a person with PD is unable to maintain a moderate weight, they or their caregiver should contact a doctor.

A doctor can help you in several ways, such as:

  • assess the person’s ability to swallow
  • refer the person to a dietitian, who can provide information about high-calorie, nutritious foods
  • adjusting PD medications
  • treat depression or other conditions affecting a person’s mood

An accurate diagnosis is usually the first step toward treating and managing weight loss in late-stage PD.

Although there are no clinical guidelines for the treatment and prevention of weight loss in advanced Parkinson’s disease, the doctor will assess a person’s symptoms, weight, and nutritional status to rule out any underlying cause.

After diagnosing the condition, the doctor may adjust the dosage of Parkinson’s disease medications or treat any underlying conditions responsible for the weight loss.

The Parkinson Foundation notes that a doctor may also recommend:

  • eat small, frequent meals every 2 to 3 hours
  • eat favorite foods
  • incorporating advice from a dietitian on how to adopt a high-calorie, nutritious diet
  • taking a doctor-approved dietary supplement
  • increase consumption of whole grains
  • avoid filling up with tea, coffee, or clear soup
  • keep easy-to-prepare foods close at hand
  • choose foods that are easy to chew, such as smoothies, ground meat, and other soft proteins
  • seasoning foods with herbs, spices, and sauces to help stimulate a person’s appetite

Weight loss is a common symptom of PD. Although it can occur at any stage, a person’s weight loss may be greatest during the later stages of the disease.

There are many reasons why people with PD typically experience weight loss. These include nausea, decreased sense of smell, depression, and medication side effects. Certain symptoms of PD, including dyskinesia, tremors, and difficulty swallowing, can also lead to weight loss.

People should contact a doctor if they are unable to maintain a moderate weight. Weight loss can lead to malnutrition and put a person at higher risk for complications.

A doctor will be able to rule out any underlying cause and provide advice on how a person can increase their appetite and gain weight safely.


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