Paul Castran was enduring fatigue, muscle aches and stiffness. None of it could be explained and, in all other ways, the 52-year-old was fit and healthy.
His doctor suggested genetic testing of his body's reaction to his diet. The simple cheek swab results revealed that Castran has a gene that responds negatively to caffeine, raising his blood pressure and increasing his chance of heart attack by 287 per cent.
Previously, the Melbourne coffee aficionado was drinking four cups a day for 30 years. He also discovered he is sensitive to statins (anti-cholesterol pills, which he takes), which can result in aches and pains, and is 66 per cent less effective at processing folate, which can cause fatigue.
''I think we might have found the problem and now, instead of a scattered shotgun approach, I can do something about it,'' he said.
He is among the first Australians to experience ''nutritional genomics'', an emerging science that explains our bodies' different reactions to diet.
Dieting is going bespoke and nutrition can be tailored not just to you, but to your genes.
''It's the way of the future,'' said Peta Adams, a Wagga Wagga dietitian and one of the first in NSW to use genetic testing in her practice.
''The results are backed up by science. Instead of someone going, 'I know I shouldn't eat that food,' you can show them that genetically they're not suited to eat that type of food.''
She has treated almost 100 people in the past year using the gene tests.
A husband and wife came to see her who were ''well-to-do, educated and not silly about food''. But the husband weighed 150 kilograms and the wife weighed 100 kilograms. ''His results came back showing he had a balanced genotype, which meant he just needed calorie modification - he didn't need low-carb or high-protein,'' Ms Adams said. ''Whereas the wife was carb-sensitive, so she had more success on an Atkins-style diet.''
The husband has now lost 20 kilograms and the wife's weight is steadily dropping.
Genetic tests to customise diet have been used in the US for several years. In Australia, genetic testing can be carried out only by healthcare professionals including doctors and dietitians.
''Genetics is one of the fastest growing areas of science,'' said Graeme Smith, the chief scientific officer at Melbourne biotechnology company MyGene.
Lynnette Ferguson, a professor at the University of Auckland, led sessions on nutritional genomics at the International Congress of Dietetics in Australia recently.
''Some people are particularly susceptible to sugar or salt,'' she said. ''For others, bringing down their salt content will do absolutely nothing.''
New York's sugary drinks crackdown vindicated by study
SUGARY soft drinks may worsen the effect of genes that put people at risk of obesity, one of several studies on how the drinks affect weight has found.
People genetically predisposed to obesity were more likely to gain weight from the beverages than those without the traits, a study published in The New England Journal of Medicine revealed. Other research showed that switching to a diet soft drink from a sugary one may help kids control weight gain.
Although sodas, sports drinks, blended coffees and other high-calorie beverages have long been assumed to play a leading role in the obesity crisis - which costs the US about $US147 billion ($140 billion) a year in health care expenses - these studies are the first to show that consumption of sugary drinks is a direct cause of weight gain, experts said. One in three adults and 17 per cent of children are obese in the US, with sugary beverages apparently the largest single caloric food source in the nation.
This month, New York City limited the cup size that restaurants can use to supply sugary drinks, and schools across the country have banned the beverages.