Visual Cues and Food Intake: Distortion Power of Plate and Spoon Size on Overweight and Obese University Staff

Abstract

Background: This study was designed to evaluate the effect of the size of plate, spoon, and fork on food and energy intake during a meal in obese or overweight staff. Methods: This was a crossover randomized controlled trial that was conducted on 40 obese or overweight clerical staff of the university. The staff was invited to have lunch randomly, receiving either a large or a small set of plate, spoon, and fork. Washout period was 3 weeks, and the participants were then invited to have lunch in a second intervention period and received opposite sizes of dishes compared to the first period sizes. The meal was composed of roasted chicken (kebab), cooked rice, vegetable salad, dairy drink, and soda. Changes in food intake between large and small utensils (plate, spoon, and fork) were analyzed with paired t-test. Results: Rice intake using small or large eating utensils was different (P = 0.02). But total energy intake was not different. The Pearson correlation test demonstrated a positive and significant correlation between rice consumption and waist-to-hip ratio (P = 0.02). Soda (P = 0.02), carbohydrate (P = 0.01), and total energy intake (P = 0.03) were negatively correlated with the age of the participant. Conclusions: It seems that only the amount of grain products consumption changes with changing in dishware size with no significant effect on total energy intake. It is recommended that the independent effect of visual cues on food intake for foods with different textures be investigated in future studies.