Background/Objectives:A potential risk factor for cardiometabolic diseases is irregular or inconsistent eating, however, research on this topic is scarce. We aimed to study associations between irregular consumption of energy intake in meals and cardiometabolic risk factors.Subject and Methods:Dietary intake data were derived from 5-day estimated diet diaries of 1768 participants of the National Survey of Health and Development. Energy intakes during predefined meals (breakfast, lunch, dinner, between meals) and daily totals were analyzed using a score for irregularity based on the deviation from the 5-day mean energy intake. Logistic regression models were used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for having the metabolic syndrome or one of its components. Models were adjusted for sex, physical activity, socioeconomic status, marital status and smoking.Results:Irregularity scores of energy intake ranged from 0-160 and were highest for between meals. An increased risk of the metabolic syndrome was associated with more irregular energy intake during breakfast (OR=1.34 (0.99, 1.81); P trend=0.04) and between meals (OR=1.36 (1.01, 1.85); P trend=0.04). Moreover, increased waist circumference was associated with irregular energy intake during breakfast (OR=1.90 (1.47, 2.45); P trend <0.01), evening meal (OR=1.36 (1.06, 1.75); P trend=0.02) and daily total (OR=1.34 (1.04, 1.72); P trend=0.01). No significant associations were found for the other components of the metabolic syndrome.Conclusions:Individuals with a more irregular intake of energy, especially during breakfast and between meals, appeared to have an increased cardiometabolic risk.