Weight loss could vary according to people’s genes, new research suggests.
Scientists gave animals diets typically followed by humans and revealed it produced very different results according to their DNA, with some becoming obese and others being made healthier, a study found.
Among those given a typical, ‘healthy’ Mediterranean diet, some saw improvements to their blood pressure and cholesterol levels, while others gained weight, depending on their genetics, the research adds.
Those given an American-style diet high in fat and refined carbohydrates, either became severely obese or experienced little change aside from an increase in liver fat, the research adds.
Results also reveal some animals became healthier when eating an Atkins-style low-carb, high-protein diet, yet others gained weight and suffered liver damage.
The same was true for those following the Japanese way of eating, which, in humans, typically involves eating sushi for its low-fat, high-omega 3 health benefits.
Lead author William Barrington from the Texas A&M College of Medicine, said: ‘My goal going into this study was to find the optimal diet. I wanted to get the diets as close to popular human diets as possible.
‘But really what we’re finding is that it depends very much on the genetics of the individual and there isn’t one diet that is best for everyone.’
The researchers analyzed how five different diets affect the health of animals over a six-month period.
The animals’ genetic make-ups were mapped out to determine if this influenced their dietary response.
One group were given an American-style diet high in fat and refined carbohydrates, particularly corn.
Three other groups followed ‘healthier’ eating regimes, including a Mediterranean diet, with wheat and red-wine extract; a Japanese diet with rice and green tea; or an Atkins-style diet, which is high in fat and protein but low in carbohydrates.
The fifth group was the control and ate a standard, nutritious diet.
Mr Barrington said: ‘In humans, you see such a wide response to diets. I wanted to get the diets as close to popular human diets as possible.’
The researchers measured the animals’ blood pressure, as well as their cholesterol, fatty liver and blood sugar levels.
They also monitored any behavioral differences, such as how active the animals were and how much they ate.
Results reveal animals’ genetics determines how they respond to different diets.
Among those following the Japanese diet, certain genetic traits caused some to develop increased liver fat and subsequent organ damage.
On the Atkins-style diet, two genetic types demonstrated improved health while another two reacted very poorly.
Mr Barrington said: ‘One became very obese, with fatty livers and high cholesterol.’
The other genetic-trait type became less active and gained body fat, but still remained lean.
Mr Barrington said: ‘This equates to what we call “skinny-fat” in humans, in which someone looks to be a healthy weight but actually has a high percentage of body fat.’
Among those eating an American-style diet, some became severely obese, while others showed little change aside from increased liver fat.
On the Mediterranean diet, certain animals became healthier, while other animals gained weight, although not to the extent they did when eating American-style food.
Mr Barrington said: ‘My goal going into this study was to find the optimal diet. But really what we’re finding is that it depends very much on the genetics of the individual and there isn’t one diet that is best for everyone.
‘One day, we’d love to develop a genetic test that could tell each person the best diet for their own genetic makeup.’
The findings were published in the journal Genetics.