A study from Stanford University reported in The American Journal of Medicine suggests the rise in obesity in the US is likely due to increased sedentary lifestyles across the nation, and not eating too many calories. The researchers came to this conclusion after studying data for the last 20 years from the US National Health and Nutrition Examination Survey (NHANES) that shows there has been a sharp decline in levels of leisure time physical activity among Americans - especially among young women - accompanied by an increase in average body mass index (BMI), while calorie consumption has remained somewhat steady. Continued at MedicalNewsToday>>