ts during the four years before enrollment.

NIEHS researchers found that men's BMI was an independent risk factor for infertility after adjusting for other factors that could affect fertility, including high BMI of the woman, age, cigarette smoking, alcohol consumption, and environmental chemicals exposure. After adjustment, there was direct correlation in infertility with inc

Men with body mass index (BMI) over 30 were significantly more likely to be infertile than normal-weight men, according to research from the National Institute of Environmental Health Sciences (NIEHS), one of the National Institutes of Health.

Body mass index (BMI) is calculated from a person's weight and height. BMI provides a reliable indicator of body fatness for most people and is used by researchers to screen for weight categories that may lead to health related issues.

The NIEHS study involved couples enrolled in the Agricultural Health Study, a large project that began in 1993 to examine factors impacting the health of farmers and their families in agricultural communities in the United States.

"Women who are overweight or obese tend to have a more difficult time becoming pregnant than normal-weight women, but whether men who are overweight or obese also have fertility problems had not been studied," says Donna Baird, Ph.D., an NIEHS epidemiologist with the study. The study is published in the September 2006 issue of Epidemiology.

The data comes from questionnaires that 1,468 farmers and their wives completed when they enrolled in the study. The wives completed an extensive family health questionnaire, including information about the couple's reproductive history. The men's history included their height and weight. The statistic required for body mass calculation. The fertility phase of the study was limited to couples comprising women under the age of 40 who reported pregnancy attempts during the four years before enrollment.

NIEHS researchers found that men's BMI was an independent risk factor for infertility after adjusting for other factors that could affect fertility, including high BMI of the woman, age, cigarette smoking, alcohol consumption, and environmental chemicals exposure. After adjustment, there was direct correlation in infertility with inc

e and is used by researchers to screen for weight categories that may lead to health related issues.

The NIEHS study involved couples enrolled in the Agricultural Health Study, a large project that began in 1993 to examine factors impacting the health of farmers and their families in agricultural communities in the United States.

"Women who are overweight or obese tend to have a more difficult time becoming pregnant than normal-weight women, but whether men who are overweight or obese also have fertility problems had not been studied," says Donna Baird, Ph.D., an NIEHS epidemiologist with the study. The study is published in the September 2006 issue of Epidemiology.

The data comes from questionnaires that 1,468 farmers and their wives completed when they enrolled in the study. The wives completed an extensive family health questionnaire, including information about the couple's reproductive history. The men's history included their height and weight. The statistic required for body mass calculation. The fertility phase of the study was limited to couples comprising women under the age of 40 who reported pregnancy attempts during the four years before enrollment.

NIEHS researchers found that men's BMI was an independent risk factor for infertility after adjusting for other factors that could affect fertility, including high BMI of the woman, age, cigarette smoking, alcohol consumption, and environmental chemicals exposure. After adjustment, there was direct correlation in infertility with inc

o have a more difficult time becoming pregnant than normal-weight women, but whether men who are overweight or obese also have fertility problems had not been studied," says Donna Baird, Ph.D., an NIEHS epidemiologist with the study. The study is published in the September 2006 issue of Epidemiology.

The data comes from questionnaires that 1,468 farmers and their wives completed when they enrolled in the study. The wives completed an extensive family health questionnaire, including information about the couple's reproductive history. The men's history included their height and weight. The statistic required for body mass calculation. The fertility phase of the study was limited to couples comprising women under the age of 40 who reported pregnancy attempts during the four years before enrollment.

NIEHS researchers found that men's BMI was an independent risk factor for infertility after adjusting for other factors that could affect fertility, including high BMI of the woman, age, cigarette smoking, alcohol consumption, and environmental chemicals exposure. After adjustment, there was direct correlation in infertility with inc

ed when they enrolled in the study. The wives completed an extensive family health questionnaire, including information about the couple's reproductive history. The men's history included their height and weight. The statistic required for body mass calculation. The fertility phase of the study was limited to couples comprising women under the age of 40 who reported pregnancy attempts during the four years before enrollment.

NIEHS researchers found that men's BMI was an independent risk factor for infertility after adjusting for other factors that could affect fertility, including high BMI of the woman, age, cigarette smoking, alcohol consumption, and environmental chemicals exposure. After adjustment, there was direct correlation in infertility with inc

ts during the four years before enrollment.

NIEHS researchers found that men's BMI was an independent risk factor for infertility after adjusting for other factors that could affect fertility, including high BMI of the woman, age, cigarette smoking, alcohol consumption, and environmental chemicals exposure. After adjustment, there was direct correlation in infertility with increased BMI, reaching a nearly 2-fold increase among obese men, those with BMI greater than 30. The connection between obesity and infertility applied to both younger and older men involved in the study.

The researchers did not query the frequency of pregnancy attempts among the couples so it may be that BMI challenged men did not try as many times as their normal weight counterparts. However, researchers did point out that the literature looking at semen characteristics show lower semen quality for overweight and obese men, as well as hormonal differences that may be related to body mass.

We can be sure that the growing recognition of obesity as an international health problem will lead to even more studies like this one. The conclusion that there is absolutely no positive attribute to becoming or staying overweight already seems unmistakable.