If you're serious about cutting calories, perhaps you should start your diet this weekend. A study found that Americans tuck away an average of 82 extra calories each Friday, Saturday and Sunday compared with other days of the week. Adults between the ages of 19 and 50 were especially prone to indulging on their days off, eating an average of 115 extra calories per weekend day. Although most people in the study got fewer calories from protein and carbohydrates on the weekend, they made up the deficit with large increases in fat and alcohol consumption, says Pamela Haines, associate professor of nutrition at the University of North Carolina and an author of the study. Over the course of the year, weekend splurging could result in weight gain of almost five pounds.