The aim of the present investigation was to study the relationship between the consumption of an inadequate breakfast and energy profile imbalance in the whole diet of preschool children. Food intake at breakfast and over the rest of the day was monitored for seven consecutive days in 110 Spanish children between 2 and 6 years of age. ‘Precise individual weighing’ was used to monitor all food taken at the subjects' day care centres. A ‘Food Record’ was used to register all other foods taken. Subjects who took breakfasts which provided ≥ 20% of daily, total energy intake showed lower daily intakes of energy, proteins, fats, saturated fatty acid (SFA), monounsaturated fatty acid (MFA), polyunsaturated fatty acid (PUFA), cholesterol (in mg/day and mg/1000 Kcal) than those who took inadequate breakfasts (which provided < 20% of daily, total energy intake). Further, their energy profiles were more favourable. The results showed that subjects who took inadequate breakfasts (breakfasts that provided less than 20% of daily, total energy intake) had total diets with worse energy profiles and fat qualities. Breakfast may simply be a reflection of overall food habits, but it is possible that the choice of breakfast foods conditions choices made over the rest of the day. It would therefore seem advisable to monitor and improve the content of this meal even during this very early stage of life.