Our first thesis is that the bulk of knowledge that is currently flowing from nutritional research institutes does not match the major societal challenges of the twenty-first century, i.e. the demographic transition towards an ageing population, the increasing burden of non-communicable disease attributable to lifestyle, and the urgent needed for sustainability. The mismatch imposes limits to the capability of nutrition science to contribute to real-world health. This capability is restricted in at least three ways: by the questions we pursue, by the technical and methodological characteristics of our approach, and by the organisation of nutrition science.

The nutrition questions have evolved throughout the centuries. The alleviation of nutritional deficiencies and the discovery of vitamins were followed by the heyday of nutrition science as applied biochemistry. Presently, mirroring the clinical evolution towards evidence-based medicine, the quest is for evidence-based nutrition, which underpins guidelines, health claims and policies. Yet the questions for the next decennia in the context of (regional) nutrition abundance are very different. New challenges lie in gaining healthy life years, preventing multifactorial diseases and multi-morbidity, designing personalised and public health nutrition strategies, providing healthy and safe diets, but also in realising food and nutrition security, and in working on a sustainable food system.

Hence, the methods in nutrition science need to change to accommodate these new questions. Reductionism is indispensable to answer questions related to specific ingredients and has been a highly successful approach for nutrition science for decades [1, 2]. However, and possibly as a result of this, exclusive emphasis on thinking in terms of substances easily becomes a dogma [12], hampering nutrition science’s ability to diversify its views on individual and public health beyond the statistical or biochemical behaviour of single molecules. To investigate the effects of isolated substances and to demonstrate causality as required by the reductionist approach, the randomised controlled trial (RCT) is the highest ranked tool in the evidence pyramid. However, in nutrition, it is difficult to transfer such trial outcomes to diets and food patterns in daily life. The composition of foods differs according to region and climate, while dietary habits and meal patterns shift per week, month, season, and food availability. Questions elicited by this real-life picture cannot be explored in the artificial environment of the RCT. Hence, while recognising the emphasis on internal validity of RCTs, the external validity of such controlled trial results is a matter of scientific and societal concern. Nutrition science needs to actively seek and embrace the addition of new, innovative concepts to adequately study the effects of nutrition on health maintenance and disease prevention in real life, in collaboration with other relevant disciplines.

The organisation of nutrition science is still strongly influenced by a reductionist focus that orients public and commercial incentives in specific directions and obscures others. Partly due to changing governmental research policies, significant funding comes from the food industry. The industry is more focused on products and nutrients than on diets and food patterns, which is further strengthened by the subsequent emphasis on health claims [12]. To re-establish its capability, nutrition science needs to adapt to changing societal contexts and revisit its organisation and financial structures. It is also important to allow for novel concepts, study designs and challenging end points, such as biomarkers for maintaining health or enhancing resilience. Drawing from the interdisciplinary richness of nutrition science, alternative perspectives on health are already available, including new dynamic concepts of health [13].