Schedules are more relaxed, so diets can slip.
Children's Hospital of Philadelphia Dietitian Liz Coover says, "There's no longer an exact time for breakfast, or lunch, there's no after-school hour."
However, Coover says it's actually a great time to adopt healthier eating.
"Fresh fruit and vegetables are a little bit more accessible, and readily available - and less expensive," said Coover.
In addition to getting more fruits and vegetables, families may also want to cut back on sweetened drinks.
So Coover says to boost the water and hold the line on the rest.
"Lemonades, fruit punches... some of them can have up to 200-250 calories," she said.
Snacks are another spot ripe for improvement.
Coover says they should be filling and nutritious.
"Green light snacks" include fruits like berries and oranges; whole wheat crackers and popcorn, which have lots of fiber; nuts; and string cheese, which has calcium and protein.
Pretzels and many crackers fall in between.
"Not terrible, but they're really not going to fill your kids up," said Coover.
And it's very easy to overeat them, too.
Put the brakes on, and check the labels when you see what look like single-serve foods.
Coover says, "There's about 300 calories and 21 grams of fat."
Adding food labels to your summer reading can help you make good choices.
But remember, these portion sizes are for teens or adults.
"For younger ages, we recommend halving that serving size," said Coover.
Just as it takes a number of tries before kids will eat a new food, Coover says you need at least 3 to 4 weeks to make healthy habits stick.
For a free cookbook with healthy makeovers of your favorite recipes, click Nutrition in the Kitchen to get your copy.