We all eat out from time to time, but have you ever wondered how many calories are in that restaurant food?

Deb Kelly, a registered dietitian at Rochester General Hospital, says a larger portion of fries can make a huge difference.

"The difference between these, in fries for example, is 400 calories," said Kelly, pointing at two different cheeseburger dinners. "In order to burn those calories, you would have to walk for an hour and a half."

It's a hard fact to face, when you're eating at a restaurant, portion size matters, especially when it comes to kids. Soda is a big culprit.

"20 years ago, we had a an eight ounce soda. Today, we have a 20 ounce soda," said Kelly.

Deb's best advice: Know the difference between a portion and a serving.

"A portion is what you eat. Serving size is what's listed on the nutrition label on a food product, and that's based on how large the package is."

A serving size is not a recommended amount of food to eat. Kelly suggests using reference points to determine the right portion for your children.

"A fist should be a cup of cereal or a baked potato. A half of cup fresh fruit, or a half a cup of ice cream should be the size of a baseball," said Kelly.

In addition to watching what they eat, as the weather gets warmer, Kelly says to get your kids outside too.

"It's important to get them outside, get them moving, involved in physical activities," said Kelly.