The aim of the study was to characterise substantial out-of-home (SOH) eaters, describe the nutritional quality of their diet, compare SOH eaters and non-SOH eaters for a set of nutritional indicators and evaluate the quality of meals consumed at home and at different places outside the home. Information on food intake was collected with two 24 h recalls. Habitual food intake was estimated by the Nusser method. Non-dietary variables were obtained using a face-to-face questionnaire. SOH eaters were defined as individuals who consume at least 25 % of their daily energy out of home. A representative sample (n 3245) of the Belgian population aged 15 years and older was randomly selected from the National Register using a multi-stage stratified procedure. Of the Belgian population, 35·2 % were defined as SOH eaters. Energy intake, energy density of the total diet and daily consumption of most food groups, except for fruits and vegetables, were substantially higher among SOH eaters compared with non-SOH eaters. Out-of-home eating was more common among men than women and decreased with increasing age. There were considerable differences in portion sizes, consumption frequency of different foods and diversity of meals according to different places of consumption. Out-of-home eating is a significant nutritional issue in Belgium and is associated with a more adverse dietary profile. Out-of-home eating, places of consumption, and specific population groups, eating substantially out of home, should consequently be taken into account when designing and evaluating nutrition policies.