The Food Journal and Food, Nutrition & Science

An alliance between The Lempert Report and The Center for Food Integrity

Food Prices and Childhood Obesity

Food Prices and Childhood Obesity

Health and Wellness

July 29, 2012

Price increases for some high-calorie foods and beverages can lead to lower children’s BMI (body mass index), according to a recent study from Economic Research Service (ERS). They found that a 10% increase in the price of sodas lowered BMI .42% over a year, and that same increase in the price of 100% juices and starchy vegetables lowered BMI .3% over a year.

Childhood obesity has become a global epidemic, and the fight against it is now a national priority. It is the topic of much discussion and debate across the country from schools to nutritionists, health professionals to the food industry. Even the First Lady, with her Let’s Move campaign, is at the forefront of the fight to make our children healthier. 

But what causes childhood obesity, and how can we prevent it? In general, childhood obesity is the result of eating too many calories and not getting enough physical activity. However, we know that there are a number of environmental factors that influence the eating and lifestyle choices of parents and children. Some of these factors, like living in a food desert where there is limited access to fresh fruits and vegetables and easier access to energy dense foods, make it difficult for families to make the healthy choice.

An additional factor is that many high-calorie foods have lower prices than healthier foods. These low prices therefore encourage households to buy and consume more unhealthy items. In fact, some public health advocates believe that lowering the prices of low-calorie foods could boost purchases of these items and lead to healthier BMI’s. 

To investigate this theory, ERS researchers took a look at children’s BMI’s from a nationally representative survey of children in kindergarten in the 1998-99 school year (that then tracked their heights and weights through eighth grade) and linked this data to prices for eight foods and beverages in the ERS Quarterly Food-at-Home Price Database.

They found that there were small but statistically significant effects of price on children’s BMI. For example, a decrease in the price of sweet snacks during the previous quarter is associated with an increase in BMI of .27%. On the flip side, a 10% decrease for low fat milk is associated with a decrease in BMI of approximately .35%. Similarly, a 10% decrease in the price of dark green vegetables is associated with a reduction in BMI of .28 percent. Household economic framework played a role here too, as lower income households were more responsive to price changes than their higher income counterparts.

“There are a number of factors that affect how consumers respond to price changes. The size of the price change, both nominal and relative to total income, matters. The larger the price change, the more likely consumers will change purchases. Hence, the higher household income, the smaller the price change is relative to total income, and the less responsive households are likely to be,” says Dr. Jessica Todd, Agricultural Economist for ERS and the study co-author.

Interestingly, increases in the price of carbonated beverages resulted in the highest decrease in BMI. While previous studies have looked at this issue for food prices, the effect of beverage prices on BMI had not been previously reviewed. Given the recent attention and popularity of taxing soda, Todd thought it important to contribute to the discussion/policy debate with empirical research on beverages as well. 

So what can we do with these findings? Todd says that parents help shape and have some control over children’s diets, yet we know that there are many factors that influence what children eat, especially as they get older. Retailers can provide information, but consumers then need to use that information, and sometimes they may be less likely to read information about nutrition. 

Subsidizing healthy food could be another effective strategy to getting children to eat healthier – the topic of much recent research, including experimental studies within the Supplemental Nutrition Assistance Program (SNAP) – but Todd also points out that price is not the only factor that affects food choices. 

The Centers for Disease Control and Prevention reports that approximately 17% (or 12.5 million) of children and adolescents aged 2 to 19 are obese, and childhood obesity has tripled over the last 30 years. Obese children are more likely to become obese adults, and if children are overweight, obesity in adulthood is likely to be more severe. Adult obesity is associated with serious health risks including diabetes, some cancers and heart disease.