Altering portion sizes and eating rate to attenuate gorging during a fast food meal: effects on energy intake.

Objective: Eating large amounts of food at a rapid rate, defined as gorging, may contribute to excess energy intake. We aimed to evaluate whether altering portion sizes and eating rate could decrease energy intake during an extra-large fast food meal.

Methods: Subjects were adolescents (n = 18), 13 to 17 years of age, who reported eating fast food > or =1 time per week. BMI exceeded the 80th percentile for all subjects. Three feeding conditions were evaluated with a crossover design. Total amounts and types of foods and beverage served during the meal were held constant across conditions, equaling approximately 125% of that consumed during a baseline assessment visit when subjects were offered unlimited amounts. The meal (chicken nuggets, French fries, and cola) was presented as 1 large serving at a single time point (condition A, standard), portioned into 4 smaller servings presented at a single time point (condition B, effects of portioning), or portioned into 4 smaller servings presented at 15-minute intervals (condition C, effects of portioning and eating rate). Energy intake across conditions was compared by using analysis of variance.

Results: Energy intake was not significantly different, whether expressed in kilojoules (mean +/- SEM: condition A, 5552 +/- 357 kJ; condition B, 5321 +/- 433 kJ; condition C, 5762 +/- 500 kJ) or relative to total daily energy expenditure (mean +/- SEM: condition A, 51.9 +/- 3.5%; condition B, 48.2 +/- 4.0%; condition C, 53.0 +/- 4.3%).

Conclusions: Adolescents consumed approximately 50% of energy needs regardless of manipulations in portion sizes and eating rate to attenuate gorging. This finding suggests that nutritional factors inherent to fast food, such as low levels of dietary fiber, high palatability, high energy density, high fat content, high glycemic load, and high content of sugar in liquid form promote excess energy intake.