Here we go again. Arrrrrrrgh.
The diet industry can't help itself, there's so much money to be made in trying to reinvent the wheel that they're trying once more. If you haven't noticed yet, the latest trendy thing to do for your health and wellness is to get your DNA profiled to learn what foods supposedly stifle your performance and soften your physique, and what foods will improve you. Suddenly tomatoes and eggplants are the reason you can't shed belly fat, or (surprise!) fatty acids from avocados are especially good for you. Or..(brace yourself)...refined sugar produces an inflammatory response in YOUR body.
Famous athletes and celebrities have been all over this. I mean, we're talking DNA here, so it has to be true...right?
Other than generally being a waste of time and money, here are three gigantic problems with this new DNA nutrition trend:
1) It Misses the Point...Completely
There is no magic bullet when it comes to gaining muscle, losing body fat, and improving physical performance. NOTHING replaces hard work. Nothing. By hard work, I mean hard physical exertion in the gym or the training facility, and I mean the mentally hard work of changing your habits for how you eat and recover. I don't care what program or menu or "list of menacing foods" you're following, if you're not working toward changing your daily life in a SLOW and PERMANENT way, you're ultimately going to fail. Restriction diets - ones that focus right off the bat on having someone restrict caloric intake or restrict their array of permissible foods - may help someone drop some body fat (and water!) in the short term, but that person is headed for a rebound sooner or later. Why? Because the shift was too fast, too dramatic, and too much for the human brain and its habit-driven chemistry to handle.
One of the popular purveyors of the DNA nutrition fad is quite irritatingly and ironically calling itself "Habit". As if what they're selling has anything to do with coaching habit change. This company claims to offer "personalized nutrition design", which sounds like a good thing. But the reality is that despite the diversity of humans we think we see in the world, there is surprisingly little variation within our actual genetic code. We share more than 99% of our genetic code with chimpanzees. In fact, you're about 50% genetically the same as a banana. When it comes to the basic metabolic processes - like pumping blood through your heart and air through your lungs - we are all extremely alike. Do you want to know what your genetic markers are for body composition? Look at your parents.
2) It's Mostly Just a Blood Test
The science of genome studies is pretty new, and therefore easy to exploit. The truth is that we still have so many unanswered questions about what exactly DNA does. If we could make broad-based health conclusions based on your DNA, you would get your DNA mapped as a rule the first time you visit a doctor, and hold the keys to the rest of your physical life. It would probably even be covered by health insurance since it would save that industry so much money in the long run! Prickly ethics aside, I think the basic reason this isn't yet standard practice is that it's not reliable to draw conclusions about your health based on your DNA. In fact, a closer look at these "DNA for Nutrition" websites reveals that MOST of the conclusions drawn from the samples you submit are based on run-of-the-mill blood test results you'd get at your regular doctor - cholesterol, triglyceride, and blood glucose levels. They make you drink a giant sugar shake and then test your body's speed at metabolizing it. Guess what? That's a simple insulin response test that has nothing to do with your DNA. If you have Type I Diabetes then, sure, a DNA test might reveal a genetic marker for diabetes, but chances are MORE THAN HIGH that you ALREADY KNOW THIS.
If you want to know how if you have actionable high cholesterol or high fasting blood glucose, have blood work done at your doctor's office AND, while you're at it, have an endocrinologist look at your hormone levels (something these DNA tests conveniently don't include). And while it might be helpful to know if your body is especially sensitive to caffeine (something the "DNA" test does include), you don't need a DNA test to know. If you've ever paid attention to how a cup of coffee makes you feel, that's enough to go on.
3) It Might Actually Harm You
So what about the other things these tests claim to show you, like gene variants for weight gain (the so-called "Fat Gene") and vitamin absorption? At best, drawing any conclusions from gene variants is questionable, and at worst, they could influence your lifestyle negatively.
For example, a DNA test that says you carry a gene variant that makes it harder for you to metabolize Vitamin D does NOT mean that it's harder for you to metabolize Vitamin D. It just means that it's a possibility. Far more significant factors? Your body's current hormonal profile and whether or not you engage in bone-building resistance training. Which do you think is more likely - that the recommended "nutrition plan" the DNA test company gives you afterward will include a simple Vitamin D supplement, or a prescription for 3x heavy resistance training? Gosh, I can't imagine what would be easier for them to "coach". In 12 months' time, I wonder if the person just taking a Vitamin D supplement will still be at risk for bone density disease.
Another example - let's say that your DNA test does show that you carry genetic markers for slower fat metabolization. How helpful is that? It doesn't mean that these genes will ever express themselves, nor does it mean that you need to be on a low-carb diet to affect fat loss. This is NOT "personalized" nutrition.
Don't Waste Your Precious Time or Money
What is perilous about this new DNA nutrition fad is the information you might misconstrue as significant and, once again, the re-packaging of optimal health as something easy to obtain - as EASY as a DNA test! Don't let the diet industry lead you down another rabbit hole. Quality coaching is rooted in behavioral science, not DNA pseudo-science. If you suspect that you have genuine allergies to certain foods, contact an allergist and find out (again, NOT accomplished through a DNA test). Women - at the onset of pre-menopause, get a bone density test and a hormone test (including thyroid). Men - get your hormones profiled as well. Don't skip your recommended colonoscopies and reproductive organ screenings. If you want to lose body fat at any time of life, pay attention to what you eat and how your body responds. Lift heavy weights regularly. Work with intelligent coaches who can guide your exercise and your habit change. These are the things you should do. You should not send away for a DNA nutrition test.