The effect of plate and bowl sizes on portion size and calorie consumption by adults and children is well documented in literature. Larger the dish the more food you or the server is likely to put on it. But how much of a difference are we really talking about?
What we know about portion size from previous studies:
- Adults and children serve themselves portions that are relative to the size of the plate partially because of the Delboeuf illusion that makes a standard portion size look smaller on a large plate and bigger on a small plate. People tend to scoop more food onto bigger plates without realizing it (4,5,6).
- Larger serving dishes and utensils also influence us to take more food (3).
- Even food and nutrition experts who are aware of proper portion sizes are susceptible to big bowl illusions (1)!
A 2013 study from the Cornell Food and Brand Lab helps to give perspective on the extent to which size of a cereal bowl impacts how much cereal children request and how much they consume. The study sought to answer two questions: Does bowl size affect the amount of cereal requested among children and does larger portion size translate into higher consumption and waste?
What this study found:
To determine the effect of bowl size on amount of cereal requested, consumed, and wasted by children two studies were conducted. In the first study, 69 preschool aged children were randomly given either an 8 or 16 ounce bowl and asked to tell servers when the bowl contained the amount of cereal that they wanted for a morning snack. The bowls were measured and researchers found that in alignment with previous findings that children:
- Requested about twice as much cereal in the larger bowls than smaller bowls.
The second two day study looked at consumption and waste. Eighteen school-aged children were randomly given either a small (8oz) or large (16 oz) bowl at breakfast one day and the opposite size the following day. As in the other study, participants were asked to notify servers when they received the amount of cereal that they desired. These slightly older children also requested over twice as much cereal in the larger bowls. Regardless of gender or BMI these children:
- Consumed 42% more cereal from the large bowl vs. the small bowl
- Wasted 26% more cereal when give the large bowl vs. the small bowl
Children in this study were also asked to indicate what size bowl they used at home from a selection of various sized bowls to determine the average bowl size that they normally eat from at home. The average bowl size that children reported using at home held 19.2 ounces (2)! According to the Academy of Nutrition and Dietetics one serving of cereal, before adding milk should be about 1 ounce.
What we can take away from this study:
Children unintentionally request more cereal in larger bowls indicating that they use the bowl as a reference for how much food they want. To combat this bowl size trickery:
- Purchase smaller bowls! An eight ounce bowl will hold a full serving size of most cereals.
- If new bowls are not an option, measure out the cereal before putting it into the bowl to maintain portion size despite the size of the bowl.
Follow these easy tips and your children may consume fewer unneeded calories and your cereal may even go farther!
- Painter, James E, Van Ittersum, Koert, and Brian Wansink. (2006). Ice Cream Illusions: Bowls, Spoons, and Self-Served Portion Sizes. American Journal of Preventative Medicine, 31(3), 240-243.
- Payne, C.R, K. Van Ittersum, K. and B. Wansink. (2013). Larger Bowl Size Increases the Amount of Cereal Children Request, Consume, and Waste. Journal of Pediatrics, 164(2), 323-326.
- Shimizu, Mitsuru, Ellen Van Kleef and Brian Wansink. (2012). Serving Bowl Selection Biases the Amount of Food Served. Journal of Nutrition Education and Behavior, 44(1), 66-70.
- Wansink , Brian, and Koert Van Ittersum. Do Children Really Prefer Large Portions? Visual Illusion Bias Their Estimates and Intake. Journal of the American Dietetic Association. (2007): 1107-1110.
- Van Ittersum, Koert, and Brian Wansink. (2012). Plate Size and Color Suggestibility: The Delboeuf Illusion’s Bias on Serving and Eating Behavior. Journal of Consumer Research, 39(2), 215-228.
- Van Ittersum, Koert and Brian Wansink. (2006). The visual illusions of food: Why plates, bowls, and spoons can bias consumption volume. FASEB Journal, 20(4), A618.