Ottaviani, J. I.; Sagi-Kiss, V.; Schroeter, H.; Kuhnle, G. G. C.

The chemical composition of foods is complex, variable, and depends on many factors. This has a major effect on nutrition research as it affects the ability to estimate actual intake of nutrients and other compounds, and the impact and consequences are largely unknown. Here, we investigate the impact of food content variability on nutrition research using three bioactives as model: flavan-3-ols, (-)-epicatechin, and nitrate. Our results show that the variability in the composition of the same foods impedes the accurate assessment of intake by the current approach of combining dietary with food composition data. This suggests that the results of many nutrition studies using food composition data are potentially unreliable and carry greater limitations than commonly appreciated, with considerable impact for dietary recommendations and public health. This limitation should be addressed by the development of better dietary assessment methods, in particular nutritional biomarkers.