A group of federal researchers concluded that people with little extra pounds have a lower chance to die than people who are normal weight, underweight or obese.

The study, which appears in this week’s Journal of the American Medical Association, reveals that there is a relation between people’s weight and what can cause their death.

The researchers’ conclusion was based on an analysis of decades of government data on more than 39,000 Americans. They suggest that being a little overweight is also risky, but the danger seems to be smaller than in the case of underweight or obese people.

This study is an update to another study from 2005, which revealed that overweighed people but not obese have a survival advantage.

In the new study, researchers used data from the National Health and Nutrition Survey (NHANES) to link deaths to body mass index (BMI). They analyzed the body mass index of people who died from several diseases.

They established that a 5-foot-7-inch person is considered underweight with a BMI of 18.5, meaning that they weigh 118 pounds or less. Normal weight people have between 119 and 159 pounds, overweighed people between 160 and 191 pounds and obese people  more than 192 pounds.

People with a BMI of at least 30, meaning obese people presented higher risks of death from cardiovascular disease, diabetes and cancers linked to obesity such as colon, breast, esophageal, pancreatic and ovarian cancers.

Having a BMI between 25 and 30, meaning overweight people did not increase the risk of dying from heart disease of any kind of cancer. Moreover, 40 percent of overweighed people were less likely predisposed to die from other causes as pneumonia, emphysema, injuries and various infections.

Study’s lead author Katherine Flegal of the U.S. Centers for Disease Control and Prevention explained that a little extra weight provide “additional nutritional reserves” that could help fighting against certain diseases.

However, she also told WebMD that overweighed or obese people should not consider the results of this study as convenient: “We should not become more complacent about overweight and obesity because of these findings. The big picture of health extends far beyond mortality. We know that having a BMI in the overweight range is associated with many adverse health effects, including an increased risk for diabetes, hypertension and cardiovascular disease as well as decreased physical function."

There were also scientists that had negative reactions regarding the results of this new study. Professor of epidemiology and nutrition at the Harvard School of Public Health, Walter Willett commented: "It's just rubbish. It's just ludicrous to say there is no increased risk of mortality from being overweight, Seattle Times reports.

Barry Popkin, obesity researcher at the University of North Carolina, Chapel Hill said that the study “is about death. This is not about health and sickness.”