Diets low in sugar and carbohydrates have been shown to improve blood glucose levels in individuals carrying the TCF7L2 risk allele, particularly the T allele of the rs7903146 polymorphism, which is linked to impaired insulin secretion and increased risk of T2D (Kondratyeva et al. 2022; Hossen et al. 2024). The gene discussed is TCF7L2; the disease is type 2 diabetes mellitus.