A person's penchant for greasy fried chips and other fatty foods can not be blamed on their genes.
An Australian study of 44 set of twins found a 'taste' for fat is not driven by genetics, rather it's all down to diet and what a person chooses to eat.
According to the research, funded by the National Health and Medical Research Council (NHMRC), a high-fat diet decreased a person's sensitivity to the taste of fat, irrespective of their body weight or genetics.
"There's this idea that maybe some people are just not as good at sensing high levels of fat, and that they're born that way," lead researcher Professor Russell Keast, Director of Deakin's Centre for Advanced Sensory Science, said.
"But what we found is that genetics does not provide any protection against the dietary influence of fat. If we eat a high fat diet, we lose our ability to sense fat," said Prof Keast.
For the study, researchers conducted an eight-week dietary intervention with 44 sets of twins, recruited from Twins Research Australia.
One twin from each pair was randomly allocated to a low-fat diet (getting less than 20 per cent of their energy from fat) or high-fat diet (getting more than 35 per cent of their energy from fat).
Those on the high-fat diet were encouraged to eat more dairy, meat and oil. But each consumed the same number of overall kilojoules and were monitored to keep within their normal weight range.
Their taste for fat was tested at the beginning, middle and end of the trial.
At each test, each twin was given three small unmarked cups of liquid, and had to identify which of the cups contained a fatty acid. If they were unable to do so, the concentration of fatty acid was increased.
At four and eight weeks, the twins on the low-fat diets were able to identify the fatty acid at a lower concentrations than their twin on a high-fat diet.
Essentially if people eat too many fatty foods the fat in the food eventually becomes "invisible" and this is problematic, explained Prof Keast.
"People who have a lower sensitivity to the fat taste, end up eating far more kilojoules from fat because they need more to feel satiated," he said.
"That's why it's vitally important we're careful with what we're eating, otherwise we will get in a bad cycle of our bodies becoming accustomed to high levels of fat and requiring higher levels of fat to become satisfied. That can then lead to obesity."
The study is published in the American Journal of Clinical Nutrition.
