Can a DNA test determine your best weight loss diet?
The basics of weight loss are always the same – use more calories than you consume – but anyone that’s spent weeks on a diet without seeing the scale move can tell you that not all diets are created equal. Sometimes it’s a matter of trial and error to find the right plan.
But what if a DNA test could help pinpoint the perfect diet? It sounds too good to be true, but a 2007 study done at Stanford University shows that this could be a promising option.
The study was fairly small, looking at only 138 women. Each participant provided a cheek swab. Based on the results, the women were divided into three groups: low carbohydrate diet responsive, low fat diet responsive, and balanced diet responsive.
Each participant was then assigned one of four diets:
- A low carbohydrate diet (Zone diet)
- A very low carbohydrate diet (Atkins)
- A very low fat diet (Ornish)
- A ‘health professionals’ diet (a low fat diet based on the United States Department of Agriculture food pyramid)
Of course, all of these diets have at least some degree of proven effectiveness, so how to determine whether genetics made a difference? In this case, some women were assigned the diet the DNA test suggested as appropriate, and some were not.
A year later, the researchers took stock. Not surprisingly, regardless of which diet the participants followed, some women lost weight, some didn’t, and some even gained. In the past, this would probably have been written off as a compliance issue – some people simply stick to diets better than others.
The differences became apparent when researchers looked at the individual dieters, based on whether the assigned plan matched the DNA recommended results. When reviewed in that light, it didn’t matter whether the diet was low carb, low fat, or balanced. All were effective, but the women on the plan that the DNA test had predicted as the best diet lost at least twice as much weight as women on an ‘inappropriate’ diet.
A DNA test for the best diet isn’t a magic bullet. Mindy Dopler Nelson, Ph.D., is a nutritional scientist at Stanford University. She pointed out to Health Daily News, “You do need to be on a reduced calorie diet. You still need to eat healthy. But there is a difference in how people process calories. Knowing your genotype is just one more tool to help the weight-loss process.”
Although the results haven’t been tested yet in larger studies, DNA test kits are already available for dieters willing to experiment, but as always, buyer beware. Even before the study was done, there were companies promising customized diet advice based on DNA. In just one investigation in 2006, the Government Accounting Office (GAO) bought DNA kits from several websites. Two employees submitted DNA samples for 14 fictitious customers.
The results were disappointing. Instead of receiving a personalized assessment, they received generic advice, like warnings that a poor diet can increase the risk of heart disease and to stop smoking. Not surprisingly, these companies attempted to entice customers into making more purchases of supplements and vitamins, sometimes costing hundreds of dollars.
Interleukin Genetics, the company that produced the test kits used in the study, also offers testing to the general public. Their basic weight management test sells for $169.00, which includes not only the test, but personalized diet and exercise recommendations and access to their online weight loss tools. A one-on-one phone consultation with a genetic expert is also available. Interleukin Genetics also offers DNA analysis aimed at identifying heart disease risks, nutritional needs, and osteoporosis risk. These tests can be purchased separately, or combined in a package to reduce cost.