Hey kids, is that broccoli in your casserole?

Does your preschooler turn her nose up at broccoli, zucchini, and everything else green? Try hiding the veggies in her spaghetti, researchers suggest.

A new study found that youngsters got more of their daily greens when researchers pureed veggies and added them to kids' main dishes at breakfast, lunch, and dinner on the sly. And the kids didn't seem to notice that anything was different -- or to like the meals any less than non-veggie-packed fare.

"We think of it as not deception, but recipe improvement," said Barbara Rolls, one of the study's authors from Pennsylvania State University in University Park.

"In this group of kids, we got most of them meeting their daily vegetable requirements -- that's pretty amazing," she told.

Although the study was done in daycare centers where kids were fed pre-made and measured meals, co-author Maureen Spill said parents could easily do similar recipe-doctoring at home. All they need is a blender.

And the technique could work for the whole family, including older kids, Rolls said. She previously found that adding pureed vegetables into adults' meals meant they ate more veggies and fewer total calories. Most of them couldn't taste the extra veggies either.

For the new study, the researchers fed prepared meals to 40 kids, age 3 to 5, one day a week for three weeks. The meals looked the same each day -- zucchini bread at breakfast, pasta with tomato sauce at lunch, and a chicken noodle casserole at dinner and for a night snack.

One day's worth of meals was prepared normally, with a typical veggie content in each entree. On the other two days, researchers added pureed cauliflower, broccoli, squash, zucchini and tomatoes to triple or quadruple every dish's dose of vegetables.

After each meal, researchers weighed the food to determine how much kids ate. The preschoolers were also allowed to eat non-doctored side dishes and snacks during the day, including fruit, cheese, and crackers.

Compared to the day when they ate standard meals, tots almost doubled their total veggie intake on the day when they chowed down on high-veggie dishes.

And more hidden vegetables in the main dish didn't mean they ate any less fruit or vegetable side dishes.

Kids also ate about 140 fewer calories on days when their meals were most veggie-packed -- which may be a particularly important finding for overweight and obese kids, the researchers wrote in the American Journal of Clinical Nutrition.

And the kids seemed to like the doctored recipes as well as the standard ones.

Rolls said parents could adopt this technique at home by pureeing their own vegetables in a blender and starting to add them slowly into family meals. The strategy works better with some recipes than with others. For example, pureed broccoli is easily recognizable in a light-colored casserole, Spill added.

The researchers also emphasized that recipe-doctoring should not be the only way to get kids to eat their veggies.

"I would urge parents to try to get vegetables into their kids' meals wherever they can," Rolls said. "This is an additional strategy that you put on top of exposing kids to real vegetables, eating the vegetables with the kids, (and) being persistent in exposing them" to vegetables.

She hopes more companies will start selling pre-pureed vegetables to make it easier for parents to add them into family meals.

Kraft has taken up a similar strategy by adding a blend of powdered cauliflower to some of its boxed macaroni and cheese, and other companies have promoted veggie-packed tomato sauces.

But the researchers encouraged parents to get involved in making the dishes themselves, and not just for their little kids. "Almost nobody is eating enough vegetables," Rolls said.