Skimp on fluids, and your body will release an antidiuretic hormone that leads to water retention that could affect the scale, Dr. Setlzer says. While this sneaky effect is one reason why the scale is a poor measure of body mass loss, you can outsmart it by drinking more—particularly if you fill your glass with water or non-calorie alternatives like unsweetened coffee and tea.
Eat Breakfast Every Day. One habit that's common to many people who have lost weight and kept it off is eating breakfast every day. "Many people think skipping breakfast is a great way to cut calories, but they usually end up eating more throughout the day, says Elizabeth Ward, MS, RD, author of The Pocket Idiot's Guide to the New Food Pyramids. "Studies show people who eat breakfast have lower BMIs than breakfast-skippers and perform better, whether at school or in the boardroom." Try a bowl of whole-grain cereal topped with fruit and low-fat dairy for a quick and nutritious start to your day.