New research suggests that a person’s genetic makeup may help explain why low-carbohydrate diets affect cholesterol levels differently from one individual to another.

The findings indicate that people who are genetically predisposed to higher levels of low-density lipoprotein (LDL) cholesterol may be particularly sensitive to saturated fat while following a low-carb diet.

The study, presented at NUTRITION 2026 by researchers including Alexa Barad, a postdoctoral scholar at Stanford University School of Medicine, examined data from the DIETFITS trial.

The original study involved more than 600 adults who followed either a healthy low-carbohydrate or healthy low-fat diet for one year.

For the new analysis, researchers examined 431 participants who had available genetic information.

They looked at the relationship between participants’ genetic characteristics, their consumption of saturated fat, the type of diet they followed and changes in their LDL cholesterol after six months.

The results showed a notable pattern. Among people following the low-carb diet, those with a greater genetic tendency toward high LDL cholesterol were more likely to experience an increase in the cholesterol level.

The increase was particularly pronounced among those who consumed more saturated fat.

Researchers believe this may help explain why two people can follow seemingly similar diets yet experience very different results.

While one person may see little change in cholesterol, another could experience a substantial increase.

The researchers used thousands of genetic variations to create what is known as a polygenic score, allowing them to estimate an individual's overall genetic tendency toward higher or lower LDL cholesterol.

In the future, such information could potentially help doctors identify people who may be more sensitive to certain dietary changes.

However, the researchers stressed that genetic testing is not necessary for people to take a practical lesson from the findings.

Instead, people should pay attention to how their bodies respond to dietary changes and monitor cholesterol levels when making significant changes to their diets.

For people following a low-carb diet, researchers suggest choosing healthier sources of fat, including nuts, seeds, olive oil and avocado, rather than relying heavily on butter, beef tallow, fatty cuts of meat and processed meats.

The researchers also cautioned that the findings are preliminary because they were presented as an abstract at NUTRITION 2026 and have not yet undergone the same peer-review process required for publication in a scientific journal.

Further studies will be needed to confirm the results and determine whether they apply to broader populations.