People with chronic obstructive pulmonary disease (COPD) often have an increased work of breathing due to airflow obstruction. As a result, their resting energy expenditure (REE) is often higher than that of healthy adults. At the same time, breathlessness, fatigue and reduced blood oxygen levels during meals may contribute to poor appetite. This combination of high energy expenditure and low dietary intake can readily lead to malnutrition and muscle wasting, particularly the loss of respiratory muscle mass. This may further accelerate the deterioration of lung function, creating a vicious cycle.
Active nutritional intervention for people with COPD is therefore an essential component of the overall treatment plan. To compensate for the additional energy expended through increased work of breathing, patients should consume sufficient calories. They should also aim for a daily intake of 1.2 to 1.5 grams of high-quality protein per kilogram of body weight to help prevent the loss and wasting of respiratory muscles.
In addition, carbohydrate metabolism produces more carbon dioxide and has a higher respiratory quotient (RQ), which may increase the ventilatory burden. In clinical practice, patients may therefore be advised to moderately increase the proportion of healthy fats in their diet while reducing their intake of refined carbohydrates.
Key Nutritional Strategies
1. Eat small, frequent meals
Divide the daily food intake into five to six smaller meals. This can help prevent excessive stomach distension from placing pressure on the diaphragm, thereby reducing breathlessness after meals.
2. Limit gas-producing and high-sodium foods
Avoid foods that are likely to cause abdominal bloating, such as beans, cruciferous vegetables and carbonated drinks, as bloating may restrict the movement of the diaphragm. Controlling sodium intake may also help reduce fluid retention and the risk of pulmonary oedema.
3. Improve the mealtime environment and eating techniques
Patients should rest adequately before meals and eat slowly, chewing each mouthful thoroughly. For patients with low blood oxygen levels, supplemental oxygen may be used during meals following assessment and advice from a doctor.
Appropriate nutritional support can significantly improve the clinical outcomes and quality of life of people with COPD. Patients are advised to undergo regular professional assessment by a registered dietitian, who can develop an individualised dietary prescription based on their nutritional status and clinical needs.
References:
National Institute for Health and Care Excellence, UK
American Lung Association. Nutrition and COPD.
IDDSI Soft Meal Guidelines