Demographic and dietary determinants of the association between dietary fibre intake and obesity in Japanese adults with type 2 diabetes: a cross-sectional study (JDDM 78).

OBJECTIVE

To evaluate the association between dietary fibre intake and obesity in Japanese outpatients with type 2 diabetes, as well as the demographic and dietary factors influencing this association.

DESIGN

Cross-sectional study with nationwide registry data on Japanese type 2 diabetes outpatients (2014–2019). Diet was self-reported via a FFQ. Obesity was defined as BMI ≥ 25 kg/m.

SETTING

Clinics throughout Japan.

PARTICIPANTS

1565 Japanese outpatients with type 2 diabetes (63·1 % men; age range 30–89 years).

RESULTS

Multivariate analysis revealed that a higher dietary fibre intake was associated with a lower risk of obesity in all participants (95 % CI = 0·439, 0·795, trend = 0·002). Stratified analysis showed a significant inverse association between fibre intake and obesity in men and the older age groups (59–89 years), but not in women or the younger age group (30–58 years). In men, higher fibre intake was associated with healthier lifestyle behaviours, including increased physical activity ( < 0·001) and non-smoking ( < 0·001), with stronger associations compared with women. Vegetables, fruits and soyabeans/soya products were strongly correlated with fibre, while grains had a weak correlation. Folate was the micronutrient most strongly correlated with fibre.

CONCLUSION

Higher fibre intake was associated with lower obesity risk, particularly in men and older age groups. These findings emphasise the need for targeted public health initiatives promoting the intake of diverse fibre-rich foods to effectively manage obesity. Further research is needed to understand sex- and age-specific factors in the fibre–obesity relationship in diverse populations.