Learn about the relationship between Parkinson’s and weight loss

Whereas it seems that much of the US population is struggling to lose weight, people with PD often have the opposite problem.  Many people with PD find themselves wanting to gain weight in order to counteract seemingly unexplained weight loss. Today, we will discuss this symptom, the potential reasons behind it, and ways to address it.

Word of caution: Rule out other health problems first.

Weight loss is a non-specific symptom and could be a sign of many medical problems including cancer, thyroid disease and other endocrine abnormalities, as well as inflammatory bowel disease and other malabsorption syndromes. Because of this, it is imperative, that weight loss is not assumed to be due to PD without a medical workup.

Once a medical workup is complete and your primary care physician is confident that there isn’t a second medical problem contributing or causing weight loss, then the weight loss can be attributed to PD.

Why does PD cause weight loss?

There are a number of hypotheses to explain why PD may cause weight loss and it is possible that the reasons vary between people and that more than one of these reasons may contribute to weight loss in any given individual.

1. Decreased appetite in PD can have many causes:

• Decreased sense of smell – PD causes poor smell, often years or decades before the onset of other symptoms. Smell is an integral part of appreciating the taste of food and people with poor smell may find that food is less appealing. This can have a direct effect on appetite and amount of food ingested.
• Apathy or the state of emotional indifference, is a common non-motor symptom in PD. With a decreased interest in activities in general, there may be a decreased interest in meal preparation and meals, leading to decreased food intake.
• Depression is also a common non-motor symptom of PD which can manifest as decreased appetite and food intake.
• Nausea can be a side effect of PD medications. It can also be caused by gastroparesis or slow emptying of the stomach, a common problem in PD. Either way, the presence of nausea can have a significant impact on appetite.

2. Increased energy expenditure can be associated with PD:

• Dyskinesias are extra movements which can be a side effect of carbidopa/levodopa. These movements can be prominent in some people and persistent throughout the day leading to excessive energy consumption (you’re burning more calories) and weight loss.
• Tremor as well as muscle rigidity, if persistent, can be causes of excessive energy consumption and subsequent weight loss.
• Although the reasons are not completely understood, PD can be associated with dysregulated energy use even without extra movements. There are many theories as to why this may be the case, including abnormalities of the hypothalamus, an area of the brain that is responsible for many automatic functions including food intake and energy metabolism.

3. Other symptoms that may contribute to weight loss in PD:

• People with difficulty swallowing associated with PD will typically slow down their eating and reduce their consumption in an attempt to eat without coughing or choking.
• PD often causes slowed transit of food through the gut which can impact absorption and cause weight loss
• Mobility issues and tremors may impede the ability to buy groceries, prepare meals, and eat, all contributing to reduced food intake.

Why worry about weight loss associated with PD?

Weight loss has been linked to a poorer quality of life and more rapid progression of PD. The reasons for this are two-fold. On the one hand, as outlined in the list above, weight loss can be a hallmark of advancing disease – as it could be a consequence of more swallowing difficulties, worsened mobility, more impaired gut function etc.

On the other hand, having weight loss can further lead to poorer health.   Inadequate food intake can contribute to malnutrition and vitamin deficiencies. Malnutrition can subsequently be the cause of increased susceptibility to infection, increased fatigue and increased frailty. The situation can spiral with more fatigue and frailty causing a further decrease in activity and function.

Osteoporosis, or porous and fragile bones, is more common in under-weight people since bone structure is dependent on weight-bearing. Since osteoporotic bones are more prone to fracture during a fall, this too can be a contributor to more disability and frailty. Bottom line is that it is important for your health to maintain a healthy weight.

What can you do about weight loss associated with PD?

If you do find yourself unable to maintain a healthy weight, discuss this with your doctor. The good news is that after a medical workup, he or she may suggest one or more of the following steps that can help you:

• Have your swallow evaluated – swallow dysfunction may not be readily apparent to you or your family and the first clear sign of swallow dysfunction may be weight loss. Therefore, weight loss often prompts a swallow evaluation. If swallow dysfunction is discovered, specific foods and food preparation may be recommended to make it easier to swallow. Swallow therapy may also be recommended to strengthen your ability to swallow.
• Visit with a dietitian – a dietitian will be able to recommend high calorie, nutritious foods such as nuts and avocados. Nutritional supplement drinks may also be helpful. A dietitian can also help you create menus that take into account your food preferences in order to encourage increased food intake. If you also have swallowing dysfunction, then the dietitian will need to recommend foods that are nutritious, high-calorie and fit within your swallowing abilities.
• PD medication adjustments – these may be necessary to control either dyskinesia or tremor that may be contributing to unnecessary energy expenditure. Medication adjustments can also help improve mobility required for food preparation and medication-induced nausea that can be affecting appetite.
• Treat depression – if depression is contributing to poor appetite, this can often be addressed with psychotherapy or anti-depressant medications.
• Figure out with family and friends how to improve food procurement and preparation. If it is becoming too difficult for you to shop for and/or prepare your food, it may be time for ask for help from family and friends. There are also programs in almost all urban areas that deliver meals to those who are not able to prepare food for themselves.

Tips and takeaways

• Despite a diagnosis of PD, weight loss should prompt a full medical workup.
• Weight loss that is attributed to PD can be caused by a variety of reasons including decreased appetite, increased energy expenditure, swallowing difficulties, and poor gut motility.
• Weight loss has been linked to a poorer quality of life in PD and may contribute to increasing frailty.
• There are steps you can take that may help. Depending on the causes contributing to weight loss, efforts to counteract weight loss could include consultation with a dietician, swallow evaluation and PD medication adjustment.
• As with all symptoms, discuss your concerns about weight loss with your doctor.