It was supposed to be an innocent childhood crush.

But when Kris, then 11 years old, confessed his feelings to the girl he liked, she said to her friends: "Oh, but he's fat."

For Kris, who is now 25, that comment would haunt him and plunge him into a decade-long struggle with body insecurities.

"I was crushed. Up till that point in my life, I'd never really registered my size or put a value to my body in that way," says the recent Yale-NUS College graduate, who does not want to be identified by his full name.

After the incident, he started being more conscious of what he calls his "chubby body" and went to great lengths to hide it while trying to rid himself of his "disgusting fat".

He recalls the day his mother walked into his bedroom while he was covering his nipples with masking tape to prevent his "man boobs" from showing through his T-shirt. He was 12.

"She was heartbroken, I could see it in her eyes," he says. "But she is my greatest supporter and often reassures me with kind words, even till today."

Still, his body image continued to bother him.

When he was in junior college, he started going to the gym and lifting weights.

To achieve his ideal body, he decided to go on a "clean" diet of only chicken breast and salad. He was in university at the time and would prepare a week's worth of food at home and keep it in a mini fridge in his dorm room.

"I guess on the surface, I was what most people would describe as 'quite fit' and 'athletic', even though I certainly didn't feel that way. I still saw myself as chubby," he says.

He turned down social gatherings as he refused to eat out and, at one point, even induced puking to purge himself of any "unclean" food he had consumed. He had frequent fainting spells as he often skipped meals if he could not find suitable healthy food, and was constantly cold and bloated.

To "flush everything out of his system", he took fat-burning supplements and drank three to four flasks of coffee daily to act as a laxative.

He also feared looking at himself. He avoided mirrors and was acutely aware of his body, even believing that he could register even the most minute day-to-day changes in his facial and body shape.

It was only when his relationship with his girlfriend ended badly after six months that he realised he needed professional help. The couple's intimacy had taken a toll because he could not bear to be shirtless in front of her, fearing that she would be disgusted with how he looked.

"I was preoccupied with how my body looked and I just wasn't present. My actions caused hurt to a lot of people. I was struggling so badly and it got to a point where I knew I needed help," he says.

In 2017, he saw a psychologist and was diagnosed with body dysmorphic disorder (BDD), a condition characterised by a disabling preoccupation with a perceived defect in one's normal physical appearance.

Last year, he discovered he has malignant vasovagal syncope, a heart condition exacerbated by his years of constant undereating.

"I was disappointed in myself, that I had enacted such violence on my body over the years," he says.

Now, he is on antidepressant medication and has learnt, through cognitive behavioural therapy, to manage his BDD better.

He is no longer on a strict diet and occasionally indulges in hawker food, but still often struggles to shake off pangs of guilt. He also stopped working out excessively and allowed himself to put on a few more kilograms, which he says is uncomfortable, but necessary for his overall health.

But Kris is in the minority of men who have sought professional help for BDD.

Dr Oliver Suendermann, a clinical psychologist at the National University of Singapore's (NUS) Clinical and Health Psychology Centre, who has worked with patients with BDD for more than seven years, says BDD sufferers are often hesitant to seek help and it is even more under-recognised and under-reported among men.

One such reason is the lack of knowledge and education on this mental illness, which can be easily misconstrued as narcissism or excessive vanity.

"Patients with BDD are often very preoccupied with perceived flaws that are usually not very noticeable to others, and they respond with compulsive behaviours such as excessively working out or grooming. But most of them do not enjoy looking into the mirror - in fact, they often feel ugly and hopeless for being stuck in this body," he says.

An academic study done in Britain in 2016 reports that BDD affects around 2 per cent of the adult population, with the number increasing among adolescents and in student populations.

Based on smaller preliminary studies done by NUS' Clinical and Health Psychology Centre, the 2 per cent is "likely to hold up" in Singapore as well, says Dr Suendermann.

Although anyone can suffer from BDD, he says that bullying is one of the major factors that heighten the risk of BDD developing among young people.

He notes also that the race for perfection might be another factor as BDD shares similar qualities with obsessive compulsive disorder (OCD).

According to the Singapore Mental Health Study, conducted in 2016 by the Institute of Mental Health, OCD is one of the top three mental disorders in Singapore, along with depression and alcohol abuse. The study did not include statistics on BDD.

While muscular dysmorphia - otherwise known as bigorexia, where sufferers are preoccupied with their musculature and build - is found almost exclusively in men, it is only a subtype of BDD.

Dr Ng Kah Wee, director of the eating disorders programme and consultant at the department of psychiatry at the Singapore General Hospital, says that women diagnosed with BDD are more likely to have an eating disorder, while male sufferers, besides worrying about their build, may be fixated on other areas of their body such as their receding hairline and the size of their penis.

As such, they may try to "cure" their perceived flaws with cosmetic or plastic surgery.

Dr Suendermann recalls a former patient who, believing that he was too short and therefore not masculine enough, spent $50,000 on leg-lengthening surgery despite the risks.

Dr Ken Ung, a consultant psychiatrist at Adam Road Medical Centre who has seen around 20 BDD patients in the past 25 years, says it is more common for people with BDD to see a plastic surgeon than a psychiatrist - resulting in the condition going undetected.

"It's a disorder of imagined ugliness so, often, they are convinced it's a physical problem they have. So they go to cosmetic clinics to seek help in correcting these perceived flaws," he says. "Another suspicion is there's a stigma around mental illness. Even if they have heard of BDD, they might not want to go to a psychiatrist."

Those who seek professional help may find it hard to stick with it.

"It may be difficult for some to accept that it's a psychological condition. There's a kind of addictive quality to it that is hard to give up because it may give them a sense of control. People are intelligent, they know that going to see a doctor means they have to give up some control so it can pose a barrier to seeking help," he adds.

Even for those who seek help, the road to recovery is long and hard.

Kris, who is now seeing both a psychologist and psychiatrist on and off, believes BDD is something he will have to live with for the rest of his life.

"I don't think it'll ever really go away. It's difficult to unlearn and to start on a blank slate when I've been struggling with this for so long. It's more of learning how to manage it and make better decisions," he says.

Now, he is in a new relationship and is learning from his past behaviours and opting to have more honest conversations with his girlfriend. His close friends are also aware of his condition and periodically check in with him.

"There's a lot of shame when discussing the male body and masculinity, but if we can be more open about it, the burden can be shared. You don't have to carry it exclusively," he says.