FOCUS ON OBESITY AND WEIGHT MANAGEMENTThe Ability of Young Adults to Estimate Portion Size and Calorie ContentSchwartz, Jaime MS, RD; Byrd-Bredbenner, Carol PhD, RD, FADAAuthor Information Portable Nutrition, New York, NY (Ms Schwartz); and Rutgers University, New Brunswick, NJ (Dr Byrd-Bredbenner). Corresponding author: Jaime Schwartz, MS, RD, Portable Nutrition, 120 E 34th St Apt 14J, New York, NY 10016 (e-mail: firstname.lastname@example.org). Topics in Clinical Nutrition: April-June 2006 - Volume 21 - Issue 2 - p 114–121 Buy Abstract This study describes the ability of young adults (N = 177, 75% female) aged 16–26 years to estimate the size and calories in typical portions of common foods. Participants served themselves typical portion sizes of 8 foods at breakfast (n = 63) or 6 foods at lunch or dinner (n = 114). Portion size selections were unobtrusively weighed and converted to volume measures. Calories in the portions were then calculated. Only 34% of volume and 22% of calorie estimates were within 25% of their actual amounts. Nearly half the volume estimates were more than 25% greater than actual amounts. Approximately one third of the calorie estimates were underestimated by 26% or more. © 2006 Lippincott Williams & Wilkins, Inc.