What was once America's breakfast of champions has recently become fare for the unfit, as the diet industry has dealt cereal a cruel blow in its crusade against carbs, sugar, and gluten – all fairly maligned for causing weight gain and other health problems – and all found in abundance in the cereal aisle of any grocery store. But is cereal really that bad for you?

The short answer is no. Choose a whole-grain cereal high in fiber and protein, yet low in sugar, and eat that cereal in moderation and America's favorite breakfast food can also be a healthy one for your morning meal – or your lunch, dinner, or evening snack. Yep, it's that healthy – at least, if you're not talking about Lucky Charms or Frosted Flake. Here are rules to follow to find the best cereals – the kind you can eat whenever you want.

Drop "Enriched Wheat," And Go For "Whole-Grain"
When shopping for cereal, go straight to the ingredient list on the box's nutritional label. If the first ingredient does not specify "whole-grain" wheat, oats, or another grain, put the box down. Refined grains like "enriched wheat" are processed and low in nutrition.

Banish High-Fructose Corn Syrup
While you're scanning the ingredient list, if you see high-fructose corn syrup on the label, ditch it and move on.

Take Note of Serving Size
From the ingredients, raise your eyes up to the serving size, which varies widely in cereals, from a measly 1/4 cup to 1 1/4 cups. If the serving is less than 1 cup, round up calories, fiber, protein, and sugar in your head (grade-school math!) so it equals a cup.

Keep It Under 250 Calories Per Cup
If your cereal has more than 250 calories per cup, it's probably not a cereal, but a granola, muesli, or other super energy-dense blend that shouldn't make up the majority of your bowl, but should be used sparingly, like a 1/4 cup sprinkling over your cereal, if you feel the need for extra flavor.

The Less Sugar, the Better
The healthiest cereals have at least 5 grams of fiber and 5 grams of protein per cup, with fewer than 10 grams of sugar. The less sugar, the better.

Try a Real Serving
When you're ready to eat your healthy cereal, complete this eye-opening experiment: Measure out a cup in a bowl. Small, isn't it? That's a serving size. You can go up to 2 cups in a bowl (up to 500 calories) if you're eating the cereal alone as a meal–reduce the amount if you add a sprinkling of a granola, muesli, or other energy-dense blend.

Add Fruit and Yogurt
To make a balanced meal out of a bowl of cereal, top approximately 350-calories worth of your favorite flake with sliced fresh fruit, a tablespoon of crushed or sliced nuts, and/or a dollop of Greek yogurt. More food groups equals more nutrients equals better health.