Most cereals are ultra-processed. That means they're infused with preservatives, packaged in plastic bags, and sprinkled with sugar.

Scientists are beginning to zero in on the dangers of processed foods like this: People who rely on these types of convenience foods tend to eat more (about 500 extra calories a day) and gain more weight than people who stick to unprocessed fruits, vegetables, grains, and other edible plants.

Instead of starting the day with cereal, many dietitians and nutrition experts suggest having a cup of plain Greek yogurt topped with nuts and berries. That will give your body healthy fats, protein, and fiber to keep you full.