Childhood provides an opportunity for establishing healthful lifestyle habits, yet little is known about diet and physical activity patterns of elementary school-aged children. A cohort of 35 boys and girls in grades 3 through 5 (mean age=9.5 years) was studied during the course of the 2004-2005 school year, providing seasonal assessments of diet and physical activity. Objectively measured data included height, weight, and pedometer step counts. Subjective data included seasonal 3-day diet diaries, a food frequency questionnaire, and a physical activity questionnaire. Participants were white, well-nourished, and within the healthy range for body mass index for age. Only three students (9%) were overweight and another three were "at risk" for overweight. Food intake patterns fell far below MyPyramid guidelines for average daily servings of fruits and vegetables. High intakes of saturated fat (average of 12% of calories) and sodium were noted, along with inadequate fiber intakes. Snacks, desserts, and entrees that contributed most to calorie and saturated fat intake were identified. Self-reported physical activity appears in line with recommendations, but step counts fall short, particularly for girls and during winter months. These findings identify targets for behavioral and environmental interventions to reduce childhood obesity risks. Additional research involving more diverse populations is warranted.