The Times
Fiona MacRae
Gerry Gajadharsingh writes:
“With the focus of COVID-19 and its association with more severe symptoms if you are obese, it’s important to remember that even if you are not obese, visceral/abdominal fat “tummy” fat carries an increased risk of other diseases including male sub-fertility. An additional two inches on the waist of a man of normal weight reduced his chances of conception by 46 per cent.
It is well known that the so-called “male factor” accounts for at least 50% of couples having difficulty conceiving. Having conducted my research into subfertility, now almost 20 years ago as part of an MPhil PhD research study, it’s still concerning when only one half of the couple, almost always the female partner, is the one who attends for advice to improve the chances of conception.
Sheena Lewis, a male fertility expert at Queens University Belfast, said that aromatase, an enzyme made by fat, could turn testosterone, which is key to sperm production, into oestrogen, the female sex hormone.
However, there are other mechanisms at play in that increased fat disposition is associated with glucose dysregulation does intern increasing insulin levels which provoke an increase in inflammatory cytokines and hormones such as oestrogen.
Another good measurement is the waist: height ratio. Calculated in centimetres ideally this should ideally be 50%. So, a man of 177cm in height and a waist circumference of 95cm has a ratio of 54%, slightly above ideal, so he should aim for a waist circumference of 89cm, a 6cm reduction, to optimise his health.”
Having a pot belly can severely reduce a man’s chances of becoming a father, a study has suggested.
Researchers from Harvard School of Public Health in Boston found that in men who were generally slim — but had a bit of a spare tyre — the extra padding reduced the likelihood of their partner becoming pregnant by almost half. An additional two inches on the waist of a man of normal weight reduced his chances by 46 per cent.
Fat produces a chemical that turns testosterone into the female sex hormone, oestrogen, experts say.
American doctors weighed and measured almost 180 men and women before they started IVF. They found that whatever a man’s weight, a bulging belly cut his odds of fatherhood. Overall, every two-inch (5cm) increase in a man’s middle cut his partner’s chances of having a baby by 9 per cent per IVF attempt, a major medical conference was told. This meant that a man whose waist wobbled in at 40 inches was a third less likely to become a father than one with a trim 32-inch tummy.
The figures stood even when other information, including the man’s age, whether he smoked and the woman’s age and weight, was factored in.
Jorge Chavarro, a researcher, said that flab stored around the middle pumped out more harmful chemicals than other fat. He told the European Society for Human Reproduction’s annual conference that it was not just women who needed to prepare for pregnancy.
“These results highlight that reproduction is a team sport and focusing exclusively on women may obscure an important part of the picture,” he said.
Haiyang Bian, a co-researcher, added: “In fact, there is growing literature suggesting that a man’s lifestyle and diet could have an important impact not only on a couple’s fertility but also on the health of their children.”
About one in seven couples have trouble conceiving and male infertility is to blame in about half of cases. Two thirds of adults in the UK are overweight or obese. The average man’s waistline is 38.2 inches (97.1cm) — 1.5 inches bigger than in 1993.
Fertility experts say that the warning about beer bellies does not just apply to men having IVF. Obese men are more likely to be impotent and they make less sperm, which is also poorer at swimming and its DNA more damaged.
Sheena Lewis, a male fertility expert at Queens University Belfast, said that aromatase, an enzyme made by fat, could turn testosterone, which is key to sperm production, into oestrogen, the female sex hormone.
Fat also has insulating properties. “A big belly hanging over the testicles will warm them up, which affects fertility,” Professor Lewis said. Abdominal fat, much of which is wrapped around vital internal organs, is linked to heart disease, diabetes and some cancers.
It has so many potential consequences that it is argued waist size should be considered alongside weight in health checks.
Professor Charles Kingsland, clinical director of Care fertility clinics, said: “A fat belly isn’t good for your health. You are eating the wrong things at the wrong time and drinking the wrong things at the wrong time.” He added that couples who could not have a baby often blamed a rare medical condition but “in fact they have just been eating rubbish and are overweight”.
Why you should watch your waist
Heart disease Belly fat — even if you are thin elsewhere — is bad for your heart. One study found that it doubled the risk of heart attacks and strokes.
Snoring Abdominal fat, in men but not in women, is linked to obstructive sleep apnoea, in which breathing can stop dozens of times while asleep, causing snoring and daytime fatigue.
Prostate cancer An extra four inches on a man’s waistline can raise his risk of developing the most aggressive form of prostate cancer by 13 per cent. He is also more likely to die from the illness.
Bowel cancer An extra inch raises the risk of bowel cancer by 3 per cent, even if the rest of the body is trim.
Diabetes A protein made by abdominal fat can make the body less sensitive to insulin and raises the risk of type 2 diabetes, which tends to develop in middle age.