Portion Control Opportunities in Children’s Diets Femke W.M. Damen, Ellen Van Kleef, Carlo Agostoni, and Eva Almiron-Roig | November 2017, Volume 71, No.11

While the current food environment of large serving sizes, high calorie density, and plentiful and inexpensive options makes it difficult for parents to properly feed their kids, practical tools are emerging that support portion size management for children.

Girl eating salad

The number of overweight people worldwide is growing at an alarming rate. An estimated 42 million children, including adolescents, worldwide are overweight (Ng et al. 2014). Consumers often believe that what they eat is more important than how much they eat. However, the rise in overweight and obesity is partly believed to be caused by the rapid growth of “supersized” portions of high-calorie foods in grocery stores and restaurants over the past decades that encourage excessive consumption.

Recent research has robustly shown that people eat more when they are served larger portions and packages but do not compensate for this increased consumption by eating less at later times. A review of 104 portion size studies showed that doubling of portion size leads to an average consumption increase of 35% (Zlatevska et al. 2014). This so-called “portion size effect” has been shown to occur for various kind of foods such as pasta, snacks, beverages, chips, and vegetables and in a variety of contexts.

Similar to adults, children tend to eat more when more food is presented to them and this tendency has been detected among children as young as 2 years of age (Fisher and Kral 2008). Although not all children respond equally, research has shown that from age 2 to 5 years, meal size promotes faster growth regardless of how often food is eaten (although frequency is also important if portion sizes are large) (Syrad et al. 2016, Duffey and Popkin 2011). This faster growth carries an associated greater risk for obesity later in life. Clear information on recommended portion sizes may help prevent excess weight gain in children.

Portion size management is therefore essential in the development of healthy eating habits of children. This means both using portion size to limit less healthy food consumption and possibly calories but also encouraging the intake of healthier foods, such as fruit and vegetables.

This article explores key factors that make it hard for both parents and children to manage portion size and some recent developments on how to support portion size management on a practical basis.

Factors Challenging Portion Control
There is no easy way to change eating habits for the good. Research may explain why it is so difficult to control our portion and serving sizes. Food consumption is often seen as a rational process with well-reasoned decisions on what to choose and how much to eat or drink. But in reality, many of these decisions are taken in a rather impulsive and intuitive way. A key problem is that today’s food environments in most Western-world countries are not very supportive of healthy portion choice. In our more accessible food environment, food and particularly nutrient-poor and calorie-dense food is plentifully available, appealing, and relatively inexpensive. This is especially the case in environments in which large amounts of foods are readily accessible, such as fast food restaurants and supermarkets. In these environments, our body’s system of hunger and fullness is often overruled by external temptations and cues on what is “normal” to eat. In other words, in such circumstances consumers may pay less attention to signals of fullness while eating.

Consumers find it difficult to precisely assess what is a suitable portion. Instead, they trust visual indicators of what a proper portion is, such as the shape and (unit) size of serving utensils and packages (Wansink 2004). Changes to the unit size, for example, can unknowingly impact how much consumers serve and eat. For example, consumers find it more acceptable to eat one larger unit (e.g., one large chocolate bar) compared to eating the same amount from smaller units (e.g., five small chocolate bars) (van Kleef et al. 2014). A complicating factor is that many people have the tendency to finish entire servings or units from a food, the so-called “completion compulsion” or plate-cleaning tendency (Siegel 1957). We simply do not stop because we are feeling full. This may be the result of being taught to clean your plate and eat what is served as a child. It has been estimated that adults eat on average 92% of what they serve themselves (Wansink and Johnson 2015). Moreover, consumers are also attracted to purchase larger portions because they seem a good deal (“value for money”).