Introduction:
High-glycaemic index diets, particularly those containing white rice, are strongly associated with insulin resistance and type 2 diabetes. While maternal dietary effects are well described, the contribution of paternal diet to offspring metabolic health remains underexplored. Understanding paternal dietary programming has implications for disease prevention across generations.

Aim:
This study investigated whether paternal consumption of white rice induces intergenerational and transgenerational metabolic dysfunction in offspring, compared with brown rice and control diets.

Methods:
Male Drosophila melanogaster were raised on control, 50% white rice, or 50% brown rice diets and maintained for 7 days (n = 30 per group, three biological replicates). Males were mated with virgin females on a standard diet to generate F1 and F2 offspring. Offspring were maintained on either a standard or high-sugar diet. Metabolic outcomes assessed included body weight, locomotor performance, haemolymph glucose, trehalose, glycogen, triglycerides, and mRNA expression of insulin-like peptide 2 (ILP2) and acetyl-CoA carboxylase (ACC). Data were analysed using one-way and two-way ANOVA with Bonferroni post-hoc tests (p < 0.05).

Results:
Paternal consumption of white rice induced insulin-like phenotypes, including hyperglycaemia, hypertriglyceridemia, elevated trehalose, and reduced locomotor performance in fathers. Female F1 and F2 offspring exhibited significantly increased glucose, trehalose, and triglyceride levels despite no direct dietary exposure (p < 0.05). Male offspring showed elevated triglycerides with milder glycaemic effects. ILP2 expression was upregulated predominantly in female offspring, while ACC expression was increased in both sexes. These effects were exacerbated by a high-sugar dietary challenge. Offspring of brown rice showed metabolic profiles comparable to those of controls.

Conclusion:
Paternal white rice consumption programs sex-specific insulin resistance–like phenotypes across generations, with female offspring being more vulnerable. These findings highlight paternal diet as a modifiable factor in metabolic disease prevention and support dietary quality, not just caloric intake, as a transgenerational health determinant.

Ethical Compliance:
All experimental procedures were conducted in accordance with institutional guidelines for invertebrate research and approved by the relevant departmental research ethics committee.

 

Keywords: White rice, paternal dietary programming, transgenerational inheritance, insulin resistance, metabolic health