Summary Moderate intake of alcohol is consistently associated with lower risks of coronary artery disease and diabetes. The only way to investigate this is by a large-scale trial and such a trial is currently being planned by an international consortium with an expected launch in 2016. Objective and smart measures of compliance are therefore highly needed at this time. The planned study also opens unprecedented possibilities to perform mechanistic studies into the biochemical, physiological and psycho-social effects of moderate drinking to better understand individual responses. MCAT will add a number of ancillary studies to the planned large-scale intervention trial, including investigations of novel sampling and fast screening methodologies for assessing longer-term average alcohol consumption. Other goals are to closely explore the metabolic, physiological and psychosocial consequences of changing drinking habits into either moderate consumption or abstaining. The methodologies will among others include metabolomics and advanced statistical prediction modelling. The major perspective is better individual health counselling with respect to moderate drinking based on solid, high-quality evidence. This could be used as a paradigm for elucidating effects of additional life-style factors and improving basic understanding of individual health. A secondary perspective is to use the novel insights into health mechanisms in other aspects of food production.