Schools participating in the National School Lunch Program, which reimburses schools for lunches provided to kids in need, are required by law to serve meals that meet these nutrition requirements:

Fruits and Vegetables Schools are required to offer at least one 1/2-cup serving of fruit and 3/4 cup of veggies per meal, and there are weekly requirements for green, red or orange, and starchy vegetable choices. Children must take at least one fruit or vegetable with their meal.

Whole Grains All grains offered must be whole-grain-rich.

Fat School lunches must be trans-fat-free, and no more than 10 percent of calories can come from saturated fat.

Dairy Milk must be fat-free, and no more than 10 percent of calories can come from saturated fat.

Calories Meals must meet age-appropriate calorie limits and portion sizes (elementary school lunches must be 550 to 650 calories, and middle school lunches must be 600 to 700 calories).

Sodium Schools must gradually reduce sodium levels in school meals until elementary school lunches contain fewer than 640 mg sodium and middle school lunches contain fewer than 710 mg.

What about snacks? All foods and beverages sold outside school programs—including vending machines, snack bars, and a la carte lines—must also meet nutrition standards. These items must be whole-grain-rich; have a fruit, vegetable, dairy product, or protein food listed as the first ingredient; be a combination food that contains at least 1/4 cup of fruit and/or vegetables; or contain 10 percent of the daily value of calcium, potassium, vitamin D, or dietary fiber and must also adhere to calorie, sodium, fat, and sugar limits. (These standards do not apply to food brought from home or sold during non-school hours, weekends, or at off-campus events such as sporting events and school plays.)