Excess weight can put a man at an increased risk of reducing his chances of fatherhood, Fertility doctors have warned. Researchers in Scotland have found said Wednesday that extra pounds can contribute to fertility problems in men, suggesting yet another reason for men to avoid piling on the pounds.

Presented Wednesday at 24th annual conference of the European Society of Human Reproduction and Embryology, the research shows that obese men have less seminal fluid and poorer quality sperm than men of normal weight. It recommends that men should try to lose extra weight before trying to have a baby.

To reach their findings, the research team, headed by said Dr Ghiyath Shayeb, from the University of Aberdeen, looked at 5,316 men attending Aberdeen Fertility Centre after having difficulties conceiving, and found a clear link between rising bodyweight and dramatically falling sperm quality.

The tests showed that obese men (with BMIs above 30) produced 60% less seminal fluid and were 40 per cent more likely to have damaged sperm than men with a healthy BMI (with BMI between 20 and 25).

Interestingly, the severely underweight men, with BMIs less than 19, were just as likely to have the same problems as obese men. They also had poorer sperm quality than men in the healthy weight range, the study has found.

"Men who are trying for a baby with their partners should first try to achieve an ideal body weight," Shayeb said. "Adopting a healthy lifestyle, a balanced diet and regular exercise will, in the vast majority of cases, lead to a normal BMI."

A separate study, presented at the conference, found that diabetes, which is closely linked to obesity, may damage male fertility. The research, conducted by researchers at Queen's University in Belfast, found that diabetes in men permanently damages their sperm. The damage is thought to be caused by high sugar levels in the men.

The team of researchers led by Con Mallidis examined sperm samples from diabetic men and found that the disease caused DNA damage in their sperm. In the tests, diabetic men had twice the rate of DNA damage in their sperm as men without diabetes.

Obesity is a known risk factor for heart disease, diabetes, and a host of other health conditions. American Obesity Association (AOA) has described the obesity on its Website as a complex, multi-factorial chronic disease involving environmental (social and cultural), genetic, physiologic, metabolic, behavioral and psychological components. It is the second leading cause of preventable death in the U.S.

Today, obesity has become a burning issue in many of the countries, mostly the developed ones. It has reached almost epidemic levels in the United States where, as of November, 2007, nearly 127 million adults are overweight, 60 million obese and 9 million severely obese.

As per the estimates of Canadian Cancerdefine Society, nearly one-third of Canadian men are obese. In the United Kingdom, where Obesity is the second biggest cause of death among people, about a fifth of the U.K. population suffers from obesity. A whopping 300 million people around the world are obese.

Diabetes is a metabolic disorder which results from the deficiency of insulindefine in the body, leading to excessive sugar build up. It is the seventh leading cause of death in the United States and can cause heart disease, blindness, kidney failure, and amputations of all or part of the legs.

Although, heredity has a significant role in diabetes as family history of the disease makes one more prone to it, poor eating habits and obesity definitely bolster the development of type 2 diabetesdefine.