NEWS

EVER wondered why a friend faded away on Atkins diet but his girlfriend didn’t lose even half as much weight? The answer could be in our genes- maybe he drops kilos eating sirloin and nuts but her DNA is better suited to pasta with pesto.

The pioneers of a new diet in South Africa claim the days of trial and error dieting are over. But is the DNA diet simply the latest fad or does it have a scientific basis? New research suggests that people can lose two to three times more weight on a diet matched to their genotype than if they are on an inappropriate diet. However, these results are from a small study among overweight women in the US.

Jo’burg dietician Anne Till says: Genetically we have not changed in the past 100 or 200 years and obesity is escalating year on year. This is not attributed to genes but to how people live. Everyone is looking for the Holy Grail of dieting and a solution to their problems. What makes all the difference is how much you eat and how much you exercise.

This holds true for the followers of any popular diet: Atkins, South Beach, Sure Slim, Weight Watchers, Anne Fill, X and Weighless. You name it.

When the Sunday Times staff did their own experiments, dubbed the Fat Wars, into how well these diets work, one point was clear: you only get results if you stick to the plan. And most of the volunteers had more fun feasting and drinking than eating green vegetables.

But back to the latest offering. To follow the DNA diet you must have eight genes tested which influence metabolism and fat loss. Results will suggest whether a low-carb, a low-fat, low-Gl (moderate carb, low fat) or healthy balanced diet will work best for you.

DNAlysis is the second company in the world to offer a DNA diet, according to its CEO, Dr Daniel Meyersfeld. He says the company tested more than 100 people in the first week of operation last month, but it is too soon to know if they will have success in losing weight. Meyersfeld, a molecular biologist, says the product is based on scientific research from the past ten years. The DNA Diet falls under an exciting new frontier in weight control known as nutrigenomics; that is, how genes and food interact. He says: The DNA Diet is not a fad. We know people respond differently to low- carb and low-fat diets. The point is to skip the guess work. Ten years ago nutrigenomics was out there scientifically and now it is in mainstream universities.

However, South African dieticians and scientists are cautious about the potential of a DNA diet. They warn it is jumping the gun to offer a diet linked to the results of a few gene tests, when about 600 genes relate to metabolic functioning and obesity.

Celeste Naude, a researcher and dietician at Stellenbosch University’s division of human nutrition, says: Analysing a few gene variants and ignoring other possible interactions within this vast genomic diversity may result in incomplete analyses and the possibility of misguided interventions.

She said the scientific evidence was in its early developmental stages. Any personalised genetically based dietary advice is premature.

The president of the Association for Dietetics in South Africa, Rene Smalberger, says: The field of genetic testing and the link between genetics and dietary prescriptions have been investigated for the past few years, with mixed results. I believe there is not enough conclusive evidence to prove the link between genetics and weigh t loss.

Gene testing and products associated with their results are available in the US. Meyersfeld said DNAlysis wanted to bring existing biotechnology to South Africa even though it was still in its early stages. Who decides when there is enough research? We are bringing in the best available test now and in a year’s time there may be 10 more genes worth testing.

Meyersfeld says the DNA test results would allow people to attain the best health, based on small lifestyle changes. We are looking at low penetrance genes. By themselves they do not cause disease or weight gain but in combination with poor lifestyle choices they can.

Till says: Low penetrance genes do not cause problems and don’t express themselves unless mixed with an unfavourable environment. She adds that there is no magic bullet to losing weight, and that DNA clues could reinforce the need for behaviour change to an individual who has a health risk. For instance, if a person finds out that they have an increased risk of high cholesterol, they should modify their diet.

Meyersfeld says that a person on a DNA diet may feel more motivated to stick to a diet designed on a case by case basis rather than a one size fits all diet. In the worst case we will have a person who does not respond well. We are not putting people onto medication or making drastic changes.

The jury is still out on whether DNA diets will deliver results but the interest in nutrigenomics is gaining momentum.



HOW IT WORKS

You sign up for the DNA diet online, pay a fee and receive a DNA diet test kit. The kit has instructions and a sterile swab inside a tube. Taking the swab is easy (I tested it). You just scrape around inside your cheek, then seal the swab stick back in the tube. You sign a consent form, fill in a questionnaire arid post the tube to the laboratory. Your DNA diet report will be ready in about 14 days The report has five parts and the key message is simple: Remember, your genes cannot change, but your diet and lifestyle can.

A summary, like this sample, gives you the results: Your genetic make-up says you are more likely to follow a Carb smart diet and a moderate intensity exercise programme compromising 15 met hours (which measure the intensity) of exercise per week. Your exercise potential is as a power athlete.