Obese with strong hearts do better than the thin and weak

• Being overweight, or even obese, with a healthy heart that can tolerate heavy exercise is better than being a lean person who pants on walking up a hill.
• High fitness levels and low body mass index (BMI) are associated with a lower risk of dying in patients with coronary artery disease. 
• To analyse the combined impact of fitness and extra weight on death due to any cause, researchers studied 855 American men and women enrolled in a heart rehabilitation programme.
• In the past, all of them had either had heart attacks, or bouts of severe chest pain related to heart problems. Some had undergone medical or surgical procedures to help unclog the blood vessels in the heart.
• To assess the fitness of the study participants, doctors made them walk on treadmills. They were each assigned a score based on the distance they could walk, and their ability to take in oxygen while exercising - both key aspects of physical fitness. The researchers used body-mass index - a ratio of height to weight - to decide whether patients were overweight or obese.
• Patients who were fit and relatively thin had the lowest risk of dying during the study period and constituted a "control" group. Fit but overweight patients were about twice as likely to die, while those who were fit but obese had three times the risk of death compared to the fit and thin control group. 
• However, things got more complicated for the unfit. Patients with poor fitness scores who were overweight were nearly 7 times more likely to die during the study compared to the control group. But normal-weight people who were unfit were nearly 10 times more likely to die.
• As long as a person with heart disease stays active, being obese does not seem to worsen their prognosis. On the other hand, having too much abdominal fat is a problem even for people who can withstand a lot of exercise