As a practicing research microbiologist/molecular biologist it pains me to constantly be the naysayer when it comes to claims that some of my own colleagues have made and continue to make with respect to the “power” of DNA sequence data. To hear these people tell it with DNA sequence data alone we can cure virtually any disease, have perfectly optimized diets, maintain ideal weight with minimal effort or by following our DNA optimized fitness plan, and live in perfect health to the ripe old age of 300 at which point we will die peacefully in our sleep.
Just like with diet/weight loss and host of other complex conditions the ability of DNA sequence data to provide meaningful inputs into rational decision making is hyped so far out proportion to the reality that it makes our discussions about the capabilities of artificial intelligence seem sane and reasonable by comparison. Saying “the science has not caught up” about this is giving way too much credit to the pushers of these “plans”, and suggests that someday it might. In the area of “fitness” at least it most likely never can and never will.
To suggest that DNA can predict a perfect diet or “fitness” regime (however fitness is to be defined) is only slightly more absurd than suggesting DNA sequence data (alone) can predict one’s likelihood of suffering from any particular complex disease in their lifetime. Despite what many have claimed the nature vs. nurture question is not at all settled and environmental factors still play a huge (and highly variable and mostly still unknown) role in the disease process (from onset to severity). The fact that environmental factors are complex, variable, and mostly unknown is why we hear so much more about DNA which is simple, and increasingly totally known. In no sense does that make it any more or less important however. In the case of diet and nutrition and perhaps even fitness there is another massively confounding and contributing factor which is the impact of a person’s gut microbiome on weight management. The role of the gut microbiome, it’s importance, and mechanisms of action are still mostly unknown as research in this area is still in its infancy.
At this point in time, and possibly forever, DNA based diet/nutrition and “fitness” advice is worthless and I would be willing to go so far as to call it a scam or a hustle. The scam artists offering these services are exploiting the ignorance of the general population for their own profit. Personalized nutrition and fitness can work, but DNA sequence information as an input to a personalized nutrition/diet or fitness plan will give zero additional value at present. This could change in the future, though with complex processes, be it disease or weight, the influence of any one component (in this example DNA sequence) becomes more and more diluted. Therefore it is possible, likely even in my view, that there may never come a time when DNA sequence data is a useful input to a weight management or general nutrition plan because its overall impact on the process of weight management and to one’s overall nutritional health is simply too tiny to be of consequence in comparison to all the other inputs. Unfortunately these other inputs are complex, variable, and still mostly unknown (sound familiar?). In the case of “fitness” the difficulty is compounded by the fuzziness of the definition of the term itself which makes the job of the scam artist that much easier.