A new study says that the sedentary lifestyle of Americans and not their high-calorie diet is to blame for rising obesity rates in the country.

Processed foods have come under much scrutiny of late due to the dramatic rise in obesity rates in the United States. However, findings of a new study suggests otherwise. According to researchers from Stanford University, the sedentary lifestyle of Americans has a larger role to play in their expanding waistlines.

For the study, researchers analyzed data from the National Health and Nutrition Examination Survey (NHANES), collected over a period of 20 years. The number of women leading sedentary lifestyles increased from 19.1 percent in 1994 to 51.7 percent in 2010. For men this number increased from 11.4 percent in 1994 to 43.5 percent in 2010. Researchers also noticed that during this period there was a sharp increase in BMI among both genders, though the biggest rise was seen among young women.

"These changes have occurred in the context of substantial increases in the proportion of adults reporting no leisure-time physical activity, but in the absence of any significant population-level changes in average daily caloric intake," explained lead investigator Uri Ladabaum in a press statement. "At the population level, we found a significant association between the level of leisure-time physical activity, but not daily caloric intake, and the increases in both BMI and waist circumference."

Researchers also noted that contrary to current hypothesis, there was no association between high-calorie diet consumption and increased obesity rates.

"Our findings do not support the popular notion that the increase of obesity in the United States can be attributed primarily to sustained increase over time in the average daily caloric intake of Americans," said Dr. Ladabaum. "Although the overall trends in obesity in the United States are well appreciated and obesity prevalence may be stabilizing, our analyses highlight troublesome trends in younger adults, in women, and in abdominal obesity prevalence, as well as persistent racial/ethnic disparities."

Does this mean consuming a high-calorie diet won't make you gain weight? Not so! The study only implies that exercising or being physically active is more important to ward away obesity than cutting down on fast food consumption. Having said that, there are still a few calorie guidelines people should follow to enjoy better weight and proper health.

To maintain proper weight, a man should consume 2,500 calories a day while women should consume 2,000 calories a day. These numbers again depend on the amount of physical activities a person indulges in, according to a health report.

ChooseMyPlate offers special guidelines on how many calories inactive people should consume daily, depending on their age and gender. The CDC recommends at least 150 minutes of moderate-intensity physical activities a week for adults aged between 19 and 64 years.

The current study was published online in The American Journal of Medicine. The study was not funded by any external source.