While the old cliché about breakfast being the most important meal of the day still holds true—because you’ll consume fewer calories over the course of the day, have stronger cognitive skills and be 30 percent less likely to become overweight or obese—new studies reveal something of a surprise for most diners: that breakfast may also be the most fattening.

According to a recent study published in the International Journal of Obesity, basing your breakfast on the wrong nutrients can sabotage your weight-loss efforts. People who began their day with high-quality protein over refined carbohydrates were able to lose 65 percent more weight, and also reported higher levels of energy throughout the day.