TUESDAY, Aug. 4, 2026 (HealthDay News) -- Genetic background and change (Δ) in saturated fat (SFA) intake contribute to low-density lipoprotein cholesterol (LDL-C) response for individuals following a healthy low-carbohydrate (HLC) or healthy low-fat (HLF) diet, according to a study presented at NUTRITION 2026, the annual meeting of the American Society for Nutrition, held from July 25 to 28 in Washington, D.C.
Alexa Barad, Ph.D., R.D.N., from the Stanford University School of Medicine in California, and colleagues conducted a secondary analysis of the DIETFITS trial involving adults aged 18 to 50 years with overweight or obesity to examine the independent and interactive effects of genetic risk and ΔSFA intake on six-month ΔLDL-C. Participants were assigned to HLC or HLF diets (223 and 208 individuals, respectively). Genetic effects on LDL-C were summarized using a polygenic score (PGS-LDL).
The researchers found that in both diet groups, there was substantial heterogeneity in LDL-C response. At six months, the percent ΔLDL-C varied from −36 to +126 percent and from −53 to +145 percent in the HLC and HLF diets, respectively. Higher genetic risk and greater ΔSFA were independently associated with greater ΔLDL-C in both diet groups. In HLC, but not HLF, there was a significant PGS-LDL x ΔSFA interaction. The association between ΔSFA and ΔLDL-C strengthened across tertiles of PGS-LDL in HLC, but not in HLF (−1.6, 5.0, and 10.5 in the lowest, middle, and highest risk tertiles, respectively).
"Our findings suggest that some individuals may be more sensitive to the LDL cholesterol-raising effects of saturated fat, particularly in the context of a low-carbohydrate diet, because of their genetic background," Barad said a statement.
