Neither diet nor exercise: this genetic detail is behind what your body weighs.
Even if you diet or train every day, DNA influences weight more than you think. This is how it impacts your metabolism and health.
DNA influences weight more than you think
In the midst of spring, with parks full of runners and plates full of fruits and vegetables, many people strive to lead a healthier life. However, a silent factor continues to have a huge impact on the outcome of those efforts: DNA influences weight, how our body responds to exercise, and also in the prevention of metabolic diseases.
Argentina faces worrying figures in nutritional health. According to updated data from UNICEF, 35% of the Argentine population lives with overweight. Even more serious, the Second National Survey on Nutrition and Health (ENNyS 2), published in 2025, revealed that 41% of children and adolescents aged 5 to 17 are overweight or obese. These alarming figures raise a key question: is it really enough to eat healthy and move more?
Beyond calories: genetics as a guide
What seemed like a distant future just a few years ago is now a concrete tool: genetic analysis can reveal how each person's body responds to food and exercise.
“There are people who have a variant in the FTO gene that predisposes them to obesity. This means they have a reduced feeling of satiety,” explains Adrián Turjanski, a researcher at CONICET and scientific director of Gen360. This means that for those with this variant, a restrictive diet may not work, and it is preferable to focus the plan on calorie burning with adapted physical routines.
Additionally, it has been proven that nutrients are not mere energy contributions. “They interact closely with our genes. This influences key aspects such as satiety, metabolism, the ability to absorb certain nutrients, the response to different types of diets, and even the risk of developing diseases. All of this helps guide what the best diet is for our body,” Turjanski expands.
Five fronts where metabolism and genetics intersect
Thinking about metabolism is no longer just about asking why one person gains weight more than another. There are five major axes where the link between genetics and metabolism becomes key:
- Obesity and body weight
- Metabolic diseases such as type 2 diabetes and cholesterol
- Food intolerances and digestive sensitivities
- Healthy eating adapted to DNA
- Individual response to physical exercise
For example, many people live with lactose or fructose intolerances, celiac disease, or gluten sensitivity, without knowing that there is a genetic basis behind it. Others have difficulties metabolizing histamine, a substance present in certain foods and released by the body during allergic reactions. This condition, called histamine intolerance, can cause symptoms such as hives, redness, headaches, or digestive problems. Genetic tests can detect these predispositions and improve quality of life by avoiding triggers.
Genes, cholesterol, and heart diseases
Regarding the most well-known metabolic diseases, such as type 2 diabetes and cholesterol, there is also a strong genetic connection. Turjanski emphasizes that keeping LDL and HDL cholesterol levels under control is essential, as imbalances in these lipoproteins are associated with the development of plaques that block arteries and increase the risk of heart attacks or cardiovascular events.
Various genes are involved in these processes. For example:
- PCSK9: under normal conditions, this gene reduces the amount of LDL cholesterol by increasing its degradation.
- LDLR: produces a protein that captures cholesterol from the bloodstream and transports it into cells.
- APOB: essential for transporting lipids in the blood, plays a key role in cholesterol levels.
Detecting variations in these genes allows for the identification of individuals with a higher predisposition to cardiovascular diseases and adjusting both their diet and lifestyle preventively.
Metabolic syndrome: a silent enemy
Another little-known but very common condition is metabolic syndrome, a set of factors that include abdominal obesity, elevated blood sugar levels, high blood pressure, and altered lipids. All these elements together drastically increase the risk of developing type 2 diabetes, heart diseases, and insulin resistance.
Here too, the genetic factor can make a difference. Knowing if a person has markers that predispose them to these disorders allows for early decisions, from dietary adjustments to changes in exercise routines.
Personalized nutrition: the new frontier of health
Experts agree that there is no universal diet. Standard recommendations may not work if each person's DNA is not taken into account. Through genetic analysis, it is possible to know how we metabolize certain foods, what types of fats affect us more, or which physical routines are most efficient.
“It is extremely important to maintain a balanced diet to have the necessary energy, prevent metabolic diseases, and make the most of nutrients during our daily activities,” says Turjanski. For this, he recommends following personalized diets that adapt to the unique functioning of each body.
Physical exercise and genetics: not everyone responds the same
Physical activity is another of the fundamental pillars. But even here, genetics makes a difference. Some people burn fat more easily; others require greater efforts. Endurance, muscle recovery, and the risk of injuries also vary.
“It is important to know the individual capacity to respond to exercise to avoid injuries and metabolize fat,” assures the CONICET scientist.
A genetic test can provide key information to choose the most suitable type of training, avoiding frustrations and improving results.
A new perspective on overall well-being
Today, genetic tests are no longer the exclusive domain of laboratory science. They are available to anyone who wants to better understand their body and make more informed decisions. They do not replace medical advice or the expertise of nutrition or physical activity professionals, but they serve as a powerful guide.
Knowing how the body reacts to certain foods, how it metabolizes fat, what type of exercise is most effective, and what diseases might appear in the future is no longer a matter of intuition or trial and error. It is concrete information, based on one’s own DNA.
And that information can be the first step toward real change.