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.
Don’t let extra hours lounging in bed stand between you and a flatter belly. While getting enough sleep can help boost your metabolic rate, sleeping in may undo any benefit you’d enjoy from catching a few extra winks. One study reveals that late sleepers who snoozed past 10:45 in the morning ate nearly 250 more calories over the course of the day, despite eating half as many fruits and vegetables as their early bird counterparts. Even worse, they chowed down on more salty, sugary, and trans fat-laden fast food than those who woke up earlier. If you happen to head out of the house early, you’re in for an additional metabolic boost; researchers at Northwestern University have found that people exposed to just a short period of early morning sunlight had lower BMIs than their late-waking counterparts.