Obesity and COPD

Apnea treatment

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Obesity and chronic obstructive pulmonary (COPD) are linked with each other in several ways, but the relationship between the two conditions is complex. They can worsen each other—and they each lead to problems such as fatigue and heart disease.

While weight loss can help slow the progression of COPD, the breathing difficulties characteristic of pulmonary disease often lead to a sedentary lifestyle and make it difficult to exercise—which can stand in the way of healthy weight loss, creating a downhill spiral. To complicate matters, COPD can cause weight loss, and very low weight is associated with a higher risk of COPD-associated mortality (risk of death).

The solution may require medical management of COPD and strategies such as following a healthy diet and exercise program.

The Link Between COPD and Obesity

Obesity and COPD are both serious medical conditions that lead to slowly declining health. COPD makes it difficult to breathe. As a result, your body's oxygen supply can be low, which causes fatigue. In the long term, COPD leads to heart failure.

Obesity often causes fatigue and it also increases the risk of pulmonary disease, stroke, heart attack, and dementia.

Obesity affects lung function in many ways, and the effect is worse if you have COPD. Excess weight increases the work of breathing, and breathing is already impaired in COPD. The additive effects can make it a struggle to breathe, and can cause dyspnea (shortness of breath).

COPD causes exercise intolerance, which is intolerable shortness of breath caused by physical activity. This leads to a sedentary lifestyle—and inactivity increases the risk of obesity.

Nightime Effects

Obesity is highly linked with sleep apnea, a condition characterized by periods of interrupted breathing during sleep. COPD is a major risk factor for transient nocturnal desaturation, which is characterized by low blood oxygen levels during sleep.

While sleep apnea and transient nocturnal desaturation are different problems, they have the same consequences—which are low energy and impaired health due to decreased blood oxygen levels.

The Obesity Paradox in COPD

While there is an unhealthy additive effect of obesity and COPD, obesity also has a protective effect on late-stage COPD. People who are underweight are at a higher risk of dying from COPD than people who are optimal weight or who are obese.

Nutritional deficits associated with being underweight make it more difficult for the body to fight disease (like COPD associated pneumonia). Additionally, late-stage COPD may cause weight loss due to the physical burden of having a chronic disease. Experts suggest that weight loss could be a sign of deteriorating COPD.

Diagnostic Testing

If you have obesity, your doctor may screen you for signs of COPD. And if you have COPD, it is a good idea to know if your weight falls under the definition of obesity.

Obesity is usually diagnosed using body mass index (BMI), which is a measure of the relationship between weight and height.

You can use a BMI chart to know if you are overweight or obese:

  • Underweight: >18.5
  • Normal: 18.5 to 24.9
  • Overweight: 25 to 29.9
  • Obese: 30.0 or 39.9
  • Morbid obesity: 40 and higher

The BMI chart isn't perfect, as it doesn't take into account factors like body type and build, but it is a good place to start. You may wish to talk to your doctor, who can consider some of these other variables and give you an estimate of your ideal weight.

Pulmonary Tests

The severity of your COPD can be assessed with imaging tests (such as chest x-ray or CT). Pulmonary function tests (PFTs) are used to evaluate lung function in COPD.

Common PFTs include:

  • Forced expiratory volume in one second (FEV1)
  • Forced vital capacity (FVC)
  • Total lung capacity (TLC)


If you are overweight or obese with COPD, weight loss is an important aspect of treatment. Safe and effective weight loss generally requires a combination of diet and physical activity.

Exercise and Pulmonary Rehabilitation

Exercise is encouraged in COPD, but you should start with a medically guided exercise regimen that is created for you. A pulmonary therapist can work with you to improve your exercise tolerance.

Incorporating pulmonary rehabilitation into your COPD treatment and weight loss plan can improve your respiratory abilities during exercise—as well as at rest, and possibly at night too.

The best types of exercise, in the long run, are going to be those that you enjoy the most.


Losing weight can be tricky. Your doctor may advise you about dietary factors besides your weight. For example, if you are low in a nutrient such as calcium or vitamin B12, you will need to incorporate foods that are rich in these nutrients when planning your diet.

Diabetes can be a complicating factor as well because it requires you to carefully plan your meals to optimize your glucose intake. And if your cholesterol or triglyceride levels are high, you may need to maintain a diet that helps you decrease these levels while you lose weight.

If you have a chronic illness like COPD, it can be helpful to consult with a dietitian when planning your weight loss diet so that you can have a plan that maintains the nutrition you need.

A Word From Verywell

Obesity and COPD are linked, but there are nuances to the relationship between the two disorders. If you are obese with COPD, a healthy approach to weight loss can help. Keep in mind that you may lose weight if your COPD worsens. Working with your medical team to put some weight on may help prevent serious consequences of your COPD.

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