Should you genes dictate your diet?
How do you choose your food?
- By its macronutrient ratio?
- By its nutrient density?
- By your desire for it?
- By your genetic makeup?
Most of us will have made food selections based on the first three; but how many of us would base our food choices on our genes? In fact, why would that even matter?
The era of personalized nutrition
Nutrigenomics – the process of using genetic testing to direct nutritional recommendations – really became a topic of interest once the Human Genome Project was published in 20031. This HGP allowed us to look at the full sequence of human genes and begin to make connections about how minuscule changes in an individual’s DNA would change how they reacted to a certain stimulus2.
In nutrigenomics, that stimulus is related to diet and the effect that the composition of the diet or a specific nutrient in a particular food would have on that individual, because of the composition of their DNA3.
Now, we’ve known for a long time – with research to prove it – that two people who may appear to be very similar in all aspects of their physical bodies, may react very differently to a similar diet plan. When we look at their response to food on a molecular level, we observe that it’s likely at least in part because of minor DNA changes between the two that dictate their individual reaction.
Many studies into nutrigenomic processes have used obesity as a focus point to evaluate the effects.
Obesity, genetics, and diet
With obesity being such a prevalent health concern in our modern-day society, much research has gone into the how, why, where, and when it occurs.
The observation that some people respond extremely well to interventions that suppress appetite, restrict calorie intake and adapt macronutrient distribution but not for others is a great topic of interest in research. This non-responsiveness in certain individuals leaves us wondering about the genetic implications of these interventions.
The question is: why wouldn’t they work?
The answer to that may come from a 2015 genomewide association study, or GWAS. Authors of the study suggest that around 20% of the variation seen in BMI across a sample of individuals comes from genetic variation4.
Without going into too much of a scientific explanation, genes are pairs of molecules along the DNA strands. When lined up in a sequence, these gene groups ensure that a specific function takes place. Within these genetic groups, errors in the coding may take place. When the DNA is being put together as you grow in the womb, typos may occur, much like when you’re quickly typing away on your keyboard and you press the wrong key. These genetic variations give rise to a slightly different function when compared to the genetic groups without the error.
One of the most commonly studied genes in obesity is called the FTO gene, which is a fat mass and obesity-associated gene.
Research shows that genetic variants in FTO can lead to higher body weight and higher risk of falling into a higher BMI category, even when other variables that may influence weight are adjusted for5.
Individuals with such variants in the FTO gene are said to respond really well to diet and lifestyle changes. That’s great! So we can simply test everyone for the FTO gene and suggest the same diet and lifestyle changes to help them to lose or maintain a healthy weight? Not so fast…
Further variations – that’s right, a genetic variation can have further variations or more ‘typos’ within the gene group! – may mean individuals that have different FTO variations respond better to certain types of diet and lifestyle interventions.
Some may gain weight by eating more dairy, others may lose weight. Some may lose more by following a high fiber diet, others may need slightly less fiber to maintain their weight. Others still simply need to do more intense bouts of physical activity to see weight loss while others need to simply move more6.
Again, this shows that there is no one-size-fits-all approach to health, and another reason you may respond poorly to dietary and lifestyle interventions that seemingly have done wonders for someone else.
While research is still being conducted in other areas of nutrigenomics, health, and the approach to dietary interventions on an individual and genetic basis, from what we see in obesity and the FTO gene, we can begin to approach our own eating patterns in a better way based on how our genes are laid out so as to benefit our bodies more and improve our response to our diet7.
A comprehensive approach
Determining your more ‘risky’ genes may offer some great insight into a personalized approach to your eating patterns, but there are additional factors to consider while doing so.
Being sure to:
- Eat whole, unprocessed foods
- Reduce toxins from your environment as much as possible
- Avoid refined and excessive sugar
- Restricting alcohol intake
- Ensuring enough good quality sleep every night
- Moving more and getting the required amount of physical activity to stay healthy
A personalized approach to your body, eating the foods that make you feel energized and well, and factoring in the above lifestyle and dietary habits are some of the most important things you can do for your health. Looking into your genes and what they may respond better to is just another piece of the puzzle that can allow you to look forward to that complete picture of health and wellbeing that you may have been seeking.
- Mathers, J.C., (2017). Nutrigenomics in the modern era. Proceedings of the Nutrition Society. 76(3), 265-275.
- Kohlmeier M, De Caterina R, Ferguson LR, et al. Guide and position of the International Society of Nutrigenetics/Nutrigenomics on personalized nutrition: part 2 — ethics, challenges and endeavors of precision nutrition. J Nutrigenet Nutrigenomics. 2016;9(1):28-46.
- Chadwick, R. (2004). Nutrigenomics, individualism and public health. Proceedings of the Nutrition Society. 63(1), 161-166.
- Locke AE, Kahali B, Berndt SI, et al. Genetic studies of body mass index yield new insights for obesity biology. Nature. 2015;518(7538):197-206.
- Fawcett KA, Barroso I. The genetics of obesity: FTO leads the way. Trends Genet. 2010;26(6):266-274.
- Gardner CD. Tailoring dietary approaches for weight loss. Int J Obes Suppl. 2012;2(Suppl 1):S11-S15.
- Ordovás Muñoz JM. Predictors of obesity: the ‘power’ of the omics. Nutr Hosp. 2013;28(Suppl 5):63-72.