BOSTON (CBS) – A new Tufts University study looked at the home packed lunches of more than 600 third and fourth graders and found that none of the meals contained servings from all five food groups.

The five food groups are fruits, vegetables, grains, dairy, and protein.

READ MORE: Hillsborough County School District Principal Arrested After Sending Explicit Texts

School cafeterias have come under fire for not serving nutritious meals to their students, but as Dr. Mallika Marshall reports, a new study finds that what parents pack from home is often much worse than what’s offered at school.

Joan Salge Blake, a Registered Dietician and Nutrition Professor at Boston University says, “There is so much backlash about the national school lunch program, but when you look at the study, you say wait a minute, what’s coming from home is not as good as what is being served in our schools.”

So Salge Blake has some tips on how to improve the quality of home packed lunches.  For example, she advises parents to shop for food with their kids.  “Allowing them to go shopping with you,” she says. “And asking what fruit do you want to have in your lunchbox.  Same with vegetables.  Not only will it be packed, it will be eaten.”

For the dreaded vegetable Salge Blake says, “The biggest secret is salsa.  Kids love salsa and it’s a serving from the vegetable group.”

READ MORE: The 16th Annual Paws In Motion Walk-A-Thon Coming Back To Manatee County

Serve the salsa with whole grain tortilla chips.

Instead of milk, you can substitute yogurt or cheese.

“All of us should be getting three servings of dairy a day,” Salge Blake explains.  “And we are falling short of that.”

Salge Blake suggests lean sandwich meats for protein and, “Think about hummus,” she says.  “And of course peanut butter sandwiches are another easy one to have.”

When asked if parents can include something sweet in a child’s lunch, she says, “If the majority of the foods are healthy, a little dessert is absolutely okay.”

MORE NEWS: Dolly Parton Released A Line Of Southern-Style Cake Mixes, But You May Have To Wait To Try Them

Salge Blake recommends the following website for more information on healthy school lunches: