. . . luxury Retirement
Not much of a bonus for fat cats: for every 10 per cent increase in body mass index (BMI) a man loses 3.27 per cent of his earnings, according to European Commission studies at Italy's University of Padua. If you're on the average annual Australian wage of $57,730, adding 10 per cent to your BMI could set you back $1888 each year. So cutting your lunch bills could boost your finances.

. . . enjoying post-dinner chit-chat
Extra kilos leave you gasping for antacids when you should be regaling the table with your hilarious sauna anecdote. The cause is acid reflux. A study of 80,000 members of a Californian health plan conducted in conjunction with the University of California confirmed the more abdominal fat you have, the more reflux you'll experience.

. . . nights waking the neighbours
Closing your eyes and imagining she's Jessica Alba may help, but it's the "uplifting" hormone testosterone that really fuels your sex drive. And it evaporates as you expand. Research in the Journal of Clinical Endocrinology and Metabolism shows a four-point rise in BMI (that's putting on 14kg for a 178-centimetre man) accelerates your natural testosterone decline by 10 years.

. . . that holiday in the Whitsundays
Your beer belly comes at a price - according to the Australian Bureau of Statistics the average Australian household spends almost $30 a week on take-away food and $17 on alcohol. In a year that total comes to $2444 and let's face it, we're all guilty of sending much more on these luxuries some weeks. It's easy to spend $50 on a meal at a nice restaurant and even easier at the pub on after-work drinks. So skip some rounds and you'll be able to fit your less rounded body into a nice pair of jeans.

. . . your half-full glass
A season-ticket on Dr Melfi's couch is another side effect of too many side orders. "Overweight people have more psychological problems," says Dr Beckie Lang of the UK Association for the Study of Obesity. Research by the US National Institute of Mental Health found that if your BMI is 30 or higher, you're 25 per cent more likely to suffer depression, bipolar disorder and panic disorder. Sign up for the squash league: a study of Harvard University graduates found depression risk was 27 per cent lower in men who played three hours of sport a week.

. . . being the daddy
If getting bigger makes you blue, you may also lose the joy of wetting your baby's head. Studies at Cornell Medical Centre in the US found SSRIs - a class of anti-depressants - can dramatically reduce sperm count. And even without the pills, that bulge could mean blanks. "Data suggests a 9kg weight increase ups infertility risk by about 10 per cent," says the Finnish Institute of Occupational Health's Markku Sallmen. Which rules out a lifetime of Father's Day golf gifts.

. . . winning a spot-the-ball competition
According to the Optometrists Association Australia, more than 70 per cent of Australians with obesity-linked diabetes will develop some changes in their eyes within 15 years of diagnosis. Research by the UK's Royal National Institute for the Blind found obesity-linked diabetes doubles your risk of age-related macular degeneration.

. . . your (sleeping) partner
Keeping your torso toned keeps things ticking in the bedroom. "Often a man will start snoring after he's put on some weight", says Colin Sullivan, a professor of medicine at Sydney University, who specialises in sleep breathing disorders. "If he loses three or four kilograms then he'll most likely stop snoring." According to The Sleep Therapy Clinic in Brisbane, excess fat causes snoring because the fatty tissue around throat restricts the airway, especially when relaxed in sleep. One in five UK couples claim snoring has a negative impact on their relationship according to research by the British Snoring & Sleep Apnoea Association. Busting out of a 40-centimetre collar is a sign that you may not have the muscle tone needed to keep your airway open sufficiently. Your wife sleeping in the car is another.

. . . your happy home
Even if you silence your nocturnal chorus, your gut could leave you gutted in love. "Obese men report more marital problems," says Jeffery Sobal, nutritional sociologist at Cornell University in the US, and co-author of Weighty Issues. Sobal concludes this may be because pressure put on these men to lose weight from their wives leads to conflict. Or maybe their other halves just jack of all the Tim Tams going missing.

. . . your place in the veterans' five-a-side team
You can call full-time on your Nani-style celebrations, but if you want to keep playing, don't over-stuff your shirt. If your BMI climbs to more than 27.5+, your odds of suffering torn knee cartilage triple, according to University of Utah studies. Too many victory toasts and your risk climbs to 15-fold as you hit a BMI of 40. The key is to keep exercising. "Don't avoid playing for fear of suffering a tear," says study author Dr Kurt Hegmann.

. . . remembering your PIN
Being overweight has a snowball effect. No, kids won't start rolling you down hills, but your risk of developing diabetes grows. And - according to research at Rush University Medical Centre in Chicago - developing diabetes means you're 65 per cent more likely to develop Alzheimer's. "Altered levels of glucose and insulin can affect the brain directly," says Dr Zoe Arvanitakis, a researcher for Rush. Check that waistline.

. . . your "wing men"
Weight gain could lead to your mates ditching you. Research by psychologist Jason Halford, of the University of Liverpool in the UK, found women reacted 22 per cent more negatively to a picture of the same, attractive, slim man when pictured next to a fat friend than a thin one. "People project negative attitudes to obesity not only on the obese, but on those who associate with them," says Halford. Superficial perhaps, but scientific all the same.

. . . your healthy mates
Strange but true: research from the University of British Columbia found the human immune system can be triggered by the sight of fat people. Using tests including word association, researchers concluded that prejudices toward fat people may be rooted in a perceived threat of infection.

. . . your dream job
A final bonus for keeping your waistline downsized could be upsizing your career expectations. A survey of personnel officers by the UK's Personnel Today magazine found that half thought obesity affected productivity and the overweight lack self-discipline. Amazingly, 93 per cent admitted that they would offer jobs to slim candidates ahead of overweight hopefuls with exactly the same experience and qualifications. Unless the larger applicant came with his own white beard and reindeer, presumably.