THERE are many reasons for people to lose weight but a new book that delves into how it can nurture sexual dysfunction and a lack of intimacy, is one of the saddest.

According to the New York Post, new book XL Love looks at the negative impacts of growing up obese in the US and how this influences a person’s first sexual experiences and relationships in adult life.

“Overweight teenage girls can be reluctant to refuse any advances out of fear that they’ll have few chances in the future for romantic and sexual attention,” journalist Sarah Varney writes in her book, citing feedback from therapists.

“Among girls who go though early puberty,” Varney writes, “there is an increased incidence of depression; alcohol, tobacco and substance abuse; riskier sexual adventures; teen pregnancy; and even suicide attempts.”

media_camera True love is hard to find when you are overweight. Photo: AAP Image/Joe Castro

Obese girls often go through puberty at a younger age than healthy-weight girls and this means they are more likely to be sexually active sooner, become pregnant or contract a sexually transmitted disease.

“Some 15 per cent of American girls now begin puberty by first or second grade,” Varney writes.

A 2011 study referred to in the book found that extremely obese high-school girls were less likely to have sex overall but when they did, 42 per cent said they had taken drugs or alcohol at the time. This is four times the rate of healthy-weight girls.

It’s a disturbing statistic especially as girls who are drunk or high have been found to go further sexually than originally intended and were more likely not to use birth control.

Pennsylvania State University Professor Jennie Noll, who is quoted in the book, “worries that heavy girls who become sexually active aren’t developing a mature sexual identity that will serve them well on their journey to adulthood.

“They’re just stuck in a cycle. (Some guy is) going to call her beautiful, (and then she thinks), ‘It felt good when that kid came on to me at the party. I slept with him.’ But it doesn’t do anything to move (her) on in a developmental fashion.”

media_camera Obese men and women can also find it harder to have a satisfactory sexual experience. Photo: AAP Image/Lukas Coch

Varney said that the picture emerging was of two extremes, girls who were entering adulthood romantically and sexually inexperienced; and those who had sex very early, by the age of 13, and often more recklessly.

“I don’t think either of those cases,” Prof Noll says in the book, “is going to have healthy relationships unless they’ve found Prince Charming.”

Varney also found other physical impacts for both men and women.

“For every 50 pounds overweight you are, you lose an inch of penis,” Dr. Edward Karpman, a California urologist, says in the book.

“A man’s penis is actually fixed to his abdominal wall, holding it in place,” Varney explains further. “The more a man’s fattening belly grows outward, ‘the more it eats their penis,’ leaving them with, according to the doctor, ‘this little nubbin of a penis.’”

Extremely obese men face an extreme version of that, called “buried penis syndrome.”

As Varney explains, “abdominal fat and skin drape out and over a man’s pubic area, causing a host of problems.”

For women, being obese can lead to difficulties reaching orgasm due to decreased blood flow to the clitoris.

If you think it’s not an issue for Aussie kids, think again. Up to 15 per cent of Australian children were obese in 2007-08.

The rate varied depending on age and gender. Boys aged between 15 and 17 years old had the highest rate, with 15.1 per cent obese. The lowest was among girls aged 10 to 14 years old, which was 3.3 per cent. However, they had the highest proportion of those overweight, at 19.7 per cent.

Australian clinical psychologist Dr Deborah Thomas said while she did not work with teenagers, she could see why reaching puberty early could impact a girl’s sexual development.

“Other girls could still be children, and the boys might have an interest (in the overweight/obese girls) because they are developing and drawn to experiment,” Dr Thomas said.

“They could be using the overweight girls, which is probably not terribly mature on the boy’s part, and really sets girls up to for promiscuous behaviour.”

How fat is fat? Body Mass Index, or BMI, is the official measure used to assess obesity, but for most people a simple waist measurement can be a better indicator

In her experience working with adults, she said she thought women were more likely to be ashamed of their bodies than men.

“I think the pressure is still greater on women (to look good),” Dr Thomas said.

But she said it was not that common for people to bring up sex as an issue when they were struggling with their weight.

“Most people are just concerned about how they feel about themselves,” Dr Thomas said. “They feel self conscious in general rather than just about sex.

“It’s often just one of the issues they put aside, that they are not going to entertain that thought, or have a sexual relationship until they lose weight.

“When you are overweight you put off a lot of things: going on a holiday, finding a partner, you put life off.”

Originally published as Risky sex and STDs: Life as an obese teen