Bread, wholegrain consumption and weight change from middle to late adulthood: a prospective cohort study

Bread is a global staple with large variations in carbohydrate quality. The role of bread for weight regulation has been controversial and few studies have investigated associations of bread consumption with long-term weight changes. Therefore, our objective was to investigate the associations of baseline intake of bread, different types of bread, and whole grains as well as plasma alkylresorcinol - a biomarker of wholegrain wheat and rye intake - with weight changes during a follow-up covering the 6th and 7th decades of life.

The current analyses were conducted in 1764 men and women (47.4 ± 0.6 years at baseline) participating in the second and third wave of the Hordaland Health Study. A food frequency questionnaire was used to estimate baseline bread and wholegrain intake. Baseline plasma alkylresorcinol concentrations were determined in blood samples. The outcome was weight change (kg) during the 20-year follow-up. Multivariate linear regression models were applied.

Participants gained on average 2.1 ± 7.4 kg during follow-up. While total bread intake at baseline was not associated with weight change, a higher white bread intake was associated with weight gain (0.017 kg/g white bread/day, 95% CI: 0.002, 0.032 kg/g white bread/day). Wholegrain consumption - but not wholegrain bread - was inversely associated with weight gain (-0.013 kg/g whole grain/day, 95% CI: -0.026, 0.000 kg/g whole grain/day). Accordingly, plasma alkylresorcinols were inversely associated with weight gain (-0.004 kg/nmol/L alkylresorcinol, 95% CI: -0.007, -0.002 kg/nmol/L alkylresorcinol).

The current study suggests that weight regulation is associated with the carbohydrate quality of breads, i.e., refined versus wholegrain breads. Wholegrain intake, based on both self-reported dietary data and objective biomarkers, may improve weight regulation from middle to late adulthood.