['To compare the difference between self-reported and calculated daily energy requirements of\xa0adults within different body mass index (BMI) categories.', 'Adults (n = 978) self-reported daily energy requirements, demographic information, and height, weight, age, and physical activity level (PAL) to calculate total energy expenditure.', 'The main effects of BMI, gender, PAL, and dieting status on the difference between self-reported and calculated energy requirements for weight maintenance were significant (P < .05); age, race/ethnicity, level of education, and being in a health-related field had no effect. Individuals across all BMI categories underestimated their energy requirements, but obese individuals underestimated to the greatest degree. Males, current dieters, and those who reported a low-active or active PAL underestimated to the greatest extent in each category.'] Do adults in all body mass index categories underestimate daily energy requirements?