Reviewed by: HU Medical Review Board | Last reviewed: July 2015. | Last updated: March 2023
Many people with chronic obstructive pulmonary disease (COPD) have trouble with losing too much weight. It is very important for people with COPD to have a healthy body weight for their height and body type. Being overweight is not healthy for people with COPD. However, being underweight is also unhealthy and can cause many problems for people with the disease.
What causes weight loss?2
A person’s body needs energy to power all of its functions. Much of this energy comes from the food and drinks that we consume, which are digested and turned into energy. The amount of energy that a kind of food or drink provides is measured using units called calories. People who regularly exercise and are physically active need to consume more calories for energy than people who do not exercise or are inactive.
A person will gain weight if they regularly consume more calories from food and drinks than their body’s processes need in order to work. For instance, if a person is inactive and doesn’t exercise, but consumes a large amount of calories, then he or she will gain weight over time.
A person will lose weight if they do not eat or drink enough calories to provide enough energy for his or her body to function well. This means that the person’s body is using up more energy than the person is consuming in calories.
Body mass index (called “BMI” for short) is a measurement that can help show if a person’s body weight is healthy or not. The BMI is calculated by comparing a person’s height and weight:
- BMI less than 18.5 = underweight
- BMI between 18.5 - 24.9 = healthy weight
- BMI between 25 – 29.9 = overweight
- BMI more than 30 = obese
To find out your BMI, there are tools available online that can calculate it for you. The website of the National Heart, Lung, and Blood Institute has an easy-to-use BMI calculator: http://www.nhlbi.nih.gov/health/educational/lose_wt/BMI/bmicalc.htm
Patients who believe they may be overweight or underweight should talk with their healthcare providers about ways to maintain a healthy body weight.
Why does COPD cause weight loss?1,3
There are several possible reasons why COPD may cause people to lose weight.
People with COPD may lose their appetite and not feel like eating, and so they do not consume enough calories. They might not have an appetite because:
- They feel short of breath or need to cough during eating, which makes it harder to eat
- They are not very active, so they do not feel very hungry
- They feel depressed
People with COPD also have to use more energy just to breathe than people without COPD. Their bodies are using extra amounts of energy even while they are resting. This may make it harder for them to consume enough calories to provide the extra energy the body needs in order to breathe. In other words, the amount of food they consumed to maintain a healthy body weight before COPD is no longer enough anymore.
How common is weight loss in people with COPD?3
Weight loss is common for people with COPD. Around 25-40% of COPD patients have a decrease in their body weights. As the disease progresses, weight loss becomes even more common.
Are there treatments that can help COPD patients gain weight?1,2,3
Weight loss can be harmful for COPD patients. Losing weight can make a person with COPD less willing to exercise or be physically active. Being underweight can even make the person’s disease and symptoms get worse more quickly than a COPD patient with a healthy body weight.
With the help of healthcare providers, COPD patients who are losing too much weight can make a plan to consume enough calories. This can help to stop the weight loss and even gain weight back. This plan might include:
- Drinking high-calorie protein shakes
- Eating smaller, more frequent meals
- Taking nutritional supplements with meals
- Prescribing medicines to help improve the appetite
It is also helpful for patients to follow an exercise routine, which can help treat weight loss along with many other symptoms of COPD.