On the cereal diet, you eat cereal and milk for two meals a day, while keeping your third meal and snacks modest in calories. It may help with short-term weight loss, but it is neither long-term or nutritionally balanced. Rather than looking at corn flakes as a way to lose weight, think of them as a way to fill up without going over budget. The same amount of energy is in a cup of oats, a slice of bread, or a piece of fruit - about 40 calories. Going back to the original question: yes, you can lose weight by eating corn flakes. However, it is not a healthy option. Your body needs different nutrients at different times, so giving it only one thing to work with limits its ability to function at its best. Consider adding some whole-grain toast, a banana, or strawberries to your breakfast so you're taking in more of the good things that nature provides.