According to a new study from UT Southwestern, reduced cardio-respiratory fitness in individuals with high body-mass index (BMI) is responsible for heart failure.
For years, we have known that individuals who are overweight or obese are at a greater risk for health problems. “Morbid obesity is a medical condition that affects the entire body,” says Dr. Dirk. One of the problems obesity can cause is heart disease.
Now, we have a better understanding of the link between a high BMI and heart trouble. This study found that a low level of fitness — not obesity itself — is the direct cause of heart failure.
In the study, which included 20,000 individuals, doctors found that low cardio-respiratory fitness (meaning the health of the heart, lungs and circulatory system) accounted for 47 percent of the risk of heart-failure hospitalization associated with increased BMI.
The study also found that once low cardio-respiratory fitness is accounted for, changes in BMI do not have a significant association with heart failure risk.
In other words, because low cardio-respiratory fitness (not high BMI) is the direct cause of heart problems, individuals can reduce their risk of heart problems by getting more physically fit. If they do that, changes in BMI (a.k.a. losing weight) have minimal effect on the risk of heart problems.
Because of this finding, the doctors conclude that the “priority should be placed on improving cardio-respiratory fitness over decreasing BMI.”
However, as we’ve discussed on this blog many times, fitness often goes hand in hand with weight. Overweight and obese individuals tend to have less energy, making it harder to do regular physical exercise. Without regular exercise, overall cardio-respiratory fitness declines. And, as the study shows, low cardio-respiratory fitness results in increased risk for heart failure.
Dr. Dirk recommends regular physical activity — along with a low-carb, high-protein diet — for losing weight and keeping it off. However, losing weight and keeping it off also lends itself to regular physical activity, because the body is in better shape to handle the stress of exercise.
It’s important to remember that overweight and obese individuals are at greater risk for other health problems in addition to heart disease.
“Obesity is a total body condition,” says Dr. Dirk. “Beyond heart failure, it can lead to high blood pressure, diabetes, acid reflux, sleep apnea, joint pain and even cancer.”
Because high BMI is associated with a range of health problems, it’s important to address the root of the problem by losing weight with a healthy diet, regular exercise and, if needed, additional help through weight loss surgery.