Why Some People Feel Great on a High-Carbohydrate Diet While Others Gain Weight from the Same Foods

Why do some people thrive on a diet rich in carbohydrates, while others quickly gain weight from the same foods? Why does coffee provide energy to some and anxiety to others? The answer lies, at least in part, in our DNA. Nutrigenomics is the science that studies how genes influence the body’s response to food — a bridge between genetics and nutrition.

What a Genetic Nutrition Test Can Reveal

Genetic nutrition tests examine genetic variations (polymorphisms) that affect:

• how we metabolize carbohydrates, fats, and proteins;
• sensitivity to caffeine, alcohol, or sodium;
• predisposition to vitamin deficiencies (D, B12, folate);
• tendency toward inflammation, oxidative stress, or obesity;
• liver detoxification capacity.

Based on these data, a specialist can design a personalized diet that supports each individual’s unique metabolism.

Limitations of Genetic Nutrition Tests

The results are not absolute predictions. Environment, stress, sleep, physical activity, and age strongly influence how genes are expressed. In addition:

• the scientific foundation varies between companies — some tests are better validated than others;
• interpretation must be performed by a nutrigenetics specialist;
• these tests serve as guidelines, not diagnoses.

Examples of Diet Adaptation Based on Genetic Variants

• Individuals with a slow variant of the CYP1A2 gene metabolize caffeine more slowly. For them, excessive coffee intake increases cardiovascular risk, so moderation is advised.
• Those with a variant of the FTO gene, associated with a predisposition to obesity, respond better to a Mediterranean diet, rich in unsaturated fats and fiber.
• Variants of the MTHFR gene can affect folic acid conversion; supplementation with methylfolate is sometimes recommended.

Available Options in Romania and the EU

In Romania, several laboratories offer nutrigenetic testing — Synlab, GenetX, Bioclinica, NutriGenetix — some including nutritional interpretation. At the European level, companies such as DNAfit, MyDNA, or 23andMe provide similar services, some with digital platforms for progress tracking.

The Takeaway

Nutrigenomics does not tell us what to eat “forever.” Instead, it helps us understand how our bodies respond to different foods. Our genes are not our destiny — they are simply a guide for making smarter everyday choices in the kitchen.

Note: The information in this article is for informational purposes only and does not replace professional medical or genetic consultation.

(Photo: Freepik)