Drink your vegetables: Center shows kids it can be easy and tasty to be green

By Marjorie S. Miller
August 11, 2015

Hiding vegetables inside other foods may not be the only way to get kids to eat their greens. The Center for Childhood Obesity and Research has another idea: Draw attention to them.

The Green Smoothie Taste Test is an outreach program of the center, in which staff members travel around the community to demonstrate making “green smoothies” — containing green vegetables — for children. Students are involved in choosing and mixing the ingredients, tasting the creations and discussing their experiences. The next demonstration will be later this month at Ag Progress Days.

The goal of the Green Smoothie Taste Test is to get youngsters to eat more vegetables. 

“Fruits and vegetables are rich in nutrients and antioxidants, and are recommended in the USDA 2010 Dietary Guidelines as a part of a healthy diet,” said Brandi Rollins, research assistant professor in the center, in Penn State's College of Health and Human Development. “Additionally, diets high in fruits and vegetables have been shown to be protective against overweight during childhood and may lower the risk of developing cancer and stroke later in life. Yet, according to recent national data, the diets of young children do not meet the USDA recommendations for fruits and vegetables, and are particularly low in dark green vegetables.”

Currently, the USDA recommends that children consume one cup of dark green vegetables per week, she said.

Green smoothies, in particular, contain dark green vegetables, fruit and often dairy. They are low in energy-dense foods and therefore may be a good way to increase children’s intake of dark green vegetables, Rollins said.

“As most parents can attest to, children eat the foods they prefer and avoid the foods they dislike,” said Jennifer Savage Williams, interim director at the center and assistant professor in the Department of Nutritional Sciences at Penn State. “Most children tend to prefer flavors that are sweet and dislike flavors that are bitter — a taste found in many dark green vegetables. It is important to give parents a toolkit of strategies that they can try if they have a picky child or child that has food neophobia, which refers to the fear of new or unfamiliar foods. Parents are often told what not to do; the key is to give them some fun and easy things that they can try to take the struggle out of mealtimes."

Children are also predisposed to easily develop preferences for energy-dense foods, which may promote high-calorie consumption and excessive weight gain.

“Identifying novel methods for increasing children's liking and eating of fruits and vegetables and reducing their intake of energy-dense foods is necessary,” Rollins said. “Given that food preferences track over time from childhood into adolescence and adulthood, intervening early can have long-term impacts on health.”

It’s not easy being green

Many dark green vegetables can taste bitter and have a tough and fibrous texture. Blending them with other tastes and textures may make them more palatable to children than the vegetables in their raw, whole form, Rollins said.

In research led by Rollins, dark leafy greens, including collards and spinach, were added to five fruit-based smoothies containing whole fruit and 100 percent fruit juice, and served in a preschool setting. The research found that 84 percent of children tried the green smoothies when initially offered by an interviewer. All who tried the green smoothies rated at least one of the five green smoothies as “yummy,” and when served their preferred smoothie during snack time, the children on average consumed 8 ounces of their preferred smoothie.

On test days, on average, children met 31 percent of their USDA weekly recommended intake for dark green vegetables.

“Together, these findings suggest that children may be willing to consume green smoothies regardless of their level of pickiness or previous exposure to fruits and vegetables. Thus, serving children green smoothies may be an effective method for increasing children’s intake of fruits and vegetables; however, our study was small and, given its promise, it deserves replication in a more diverse, less advantaged population of children,” Rollins said.

Mixing it up around town

In April at Radio Park Elementary School in State College, staff members from the center conducted the green smoothie taste test with about 40 children.

“The kids enjoyed looking at all of the beautiful ingredients, the freshly sliced fruits and veggies on a big platter, and tasting some of them,” said Patricia McKenna, on-site supervisor of Community Education Extended Learning for the State College Area School District.

McKenna said the students were intrigued by the idea of mixing all the ingredients into a drink. 

“They were shocked that something with kale in it could taste good,” she said.  “Tasting and comparing three different smoothies was very fun for them. The children even discussed the differences and their preferences among themselves and were excited to be asked for their opinions.”

The center staff performed a similar taste test at the Park Forest Elementary School health fair, also in State College.

In that taste test, children were served 2-oz samples of a “green” smoothie made of common fruits, such as bananas, and dark green vegetables, such as spinach.

The children were asked to taste the smoothie and decide whether they thought the smoothie was “yummy,” “yucky,” or “just okay.” Next, the children were asked to guess what was in the smoothie, and for each ingredient, a picture of the ingredient was shown so everyone could see what the fruit or vegetable looked like.

As each ingredient was identified, the presenter indicated key nutrients, such as vitamin C, contained within the ingredient, and briefly described what the nutrient was good for.

green smoothie graphic

Center staff performed a taste test at the Park Forest Elementary School health fair. Children were served 1oz-tasting cups of a green smoothie, and decide whether they thought the smoothie was “yummy,” “yucky,” or “just okay.” The smoothies were comprised of common fruits, such as bananas, and dark green vegetables, such as spinach. 

IMAGE: Dennis Maney

This game was played with 25 groups of 15 to 20 children in kindergarten through fifth grade, reaching about 500 children over the course of the day.

In June, Rollins and Alison Borkowska, instructor in the Department of Nutritional Sciences at Penn State, demonstrated two green smoothie recipes at the 2015 College of Health and Human Development cooking program, “Cook Like a Chef.”

The smoothies contained a mix of spinach, kale, pineapple, bananas, orange juice, apple juice and soy milk.

“I think it is important to illustrate to children that there are more versatile and tasty ways to incorporate leafy green vegetables into your diet,” Borkowska said.

The camp, located on the University Park campus, included about 30 elementary school-aged children.

“I was thrilled to see how much the kids enjoyed drinking the smoothies,” Borkowska said. “They were pleasantly surprised. Children who were reluctant to try it, when they did, pretty much all enjoyed it. I can't think of a child who tasted it who did not like it.”

Rollins and center staff will next bring the Green Smoothie Taste Test to Ag Progress Days, hosted by Penn State’s College of Agricultural Sciences, in Pennsylvania Furnace, Pennsylvania. Rollins’s demonstration will take place from 4 to 4:30 p.m. on Aug. 18. Ag Progress Days runs from Aug. 18 – 20.

  • Green smoothies

    Green smoothies, as part of the Green Smoothie Test, is an outreach program of the center, in Penn State’s College of Health and Human Development. Staff members travel around the community to demonstrate making “green smoothies”—containing green vegetables—for children. Students are involved in choosing and mixing the ingredients, tasting the creations, and discussing their experiences. 

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    IMAGE: Brandi Rollins

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Last Updated August 13, 2015