If your momma sent you off to school with a hearty breakfast, she had good reason.

In 1985, a national sample of Australian children reported whether they ate breakfast in the morning. Twenty years later, researchers followed up with 2,184 of the participants to see how they had fared. Those who skipped breakfast regularly as a child and as an adult had higher levels of cholesterol and fasting insulin (a risk factor for type II diabetes), along with a larger waist size.

Skipping breakfast was also associated with smoking, watching TV, eating a less healthy diet and being inactive. Even after controlling for sociodemographic factors (like marital status and education), smoking and physical activity, subjects who skipped breakfast still had bigger waists.

Skipping breakfast may pack on the pounds by altering your metabolism to store more fat, or leading you to eat more later. If you want a trim waist, wake up in time for breakfast, just like your momma made it!