Too Much TV Reduces the Benefits of Physical Activity

In [a] new study, Dr GF Dunton and colleagues at the National Cancer Institute used a phone survey to collect information on a sample of 10,000 non-underweight Americans above the age of 21. Participants self-reported their height and weight, as well as the amount of time that they had spent engaging in both physically active and sedentary behaviors in the past 24 hours. Not surprisingly, time spent engaging in sedentary behaviors like watching TV and driving in a car were associated with increased body weight, while high levels of physical activity were associated with lower body weights. But what is really interesting is that sedentary behaviors altered the relationship between physical activity and obesity.