Could DNA-based diets reveal your ideal diet?
Is the secret to weight loss and metabolic fitness locked in our own genes?
Several genetic differences have been associated with obesity – the most famous of these genes is the FTO gene – and known specific gene variants are linked with the way some foods and nutrients are metabolized.
These findings led to the vision that the future of weight management lies with personalized, genetically tailored eating plans.
Food4Me is a European Union project tasked with studying the opportunities, challenges and potential of personalized diet plans. So far, its personalized diet plans integrating genetic information have demonstrated no clear advantage for weight loss.
Commercial genetics-based plans, such as Habit, Nutrigenomix and Profile are, however, already in the market, and offer their services directly to the consumer. They promise that their testing and individualized plans lead to better weight loss and disease prevention, and encourage you to start eating by your genes.
A group of researchers set out to analyze all the relevant scientific studies looking at the validity of genetics based diet recommendations. Their newly published findings appear in Advances in Nutrition.
Of the 10,000 articles in the scientific literature in the field, 39 met the criteria for inclusion. These studies looked at many genes associates with obesity, BMI, carbohydrate and fat metabolism, eating behaviors and appetite regulation.
The main finding was that there were no consistent associations between the genes and energy, fat and carb intake.
The authors conclude:
“The current knowledge is too limited to derive dietary advice for weight management on the basis of genetic information. More efforts and clinical trials are needed to understand the mechanisms behind genetic variants and how they may interact with the lifestyle and environment.”
Which is not to say that the gene-diet connection isn’t important, but rather that the researchers think that the science just isn’t there yet.
Genes, environment, behavior and choices
Personalization makes a lot of sense in pretty much every aspect of life, and much like there isn’t a one-size-fits-all in clothing, given our biologic variability, microbiome differences, diverse food preferences and food cultures, personalized diet plans are a great idea.
We now know that certain genes affect the inner works of our metabolism – we know the genes that affect caffeine metabolism and lactose intolerance, for instance, and we know that some people need to be much more careful about sugars, since their tolerance of it is imperfect, putting them at greater risk of diabetes.
On the other hand, it seems that diet recommendations based on genetic testing are based on some science, but the marketing may be way ahead of solid evidence. The predictive value of some of these gene variants is often way exaggerated, and finding a susceptibility gene might overstate the importance of genes, as behavior is often much more important than genetic makeup.
Nutrigenomics, the study of the interaction of nutrition and genes, holds great promise, but at this point, I think we need to be careful – there’s much we don’t yet know, and relying on technology isn’t necessarily better that heeding simple common sense – eat more plants, more whole foods, cut the highly processed stuff, limit added sugar.
What’s for sure, personalized plans and individual sessions make people pay attention to healthy eating. The investment of money and time may also help – the justification of the expense is extra subconscious motivation.
And thinking, planning, focusing on a better eating plan and healthier habits is in itself helpful.
In that sense, all thoughtful diets work.