When you drink liquid carbs, like the sugar in soda, your body doesn't register them the same way as, say, a piece of bread, according to a review of studies published in Current Opinion in Clinical Nutrition & Metabolic Care. That means, even though you're taking in calories, your fullness cues aren't likely to signal that you're satisfied once you finish off a can. And that can lead to consuming more overall.
And as people get older they tend to become less active, which means you burn fewer calories all day long. Plus, you naturally lose muscle mass due to hormonal changes, which further drops your daily calorie-burn rate. Muscle tissue burns more calories than fat tissue, so a body with less lean tissue has a lower metabolism and is prone to weight gain.
Work your core. When many people think of core strengthening, they think of stomach crunches. Crunches are helpful for building abdominal muscles, but contrary to popular belief, crunches won't do much to lose the layer of fat stored in your belly, and can actually cause significant damage to the spine. Instead, try a workout routine that strengthens your whole core, like yoga, or try abdominal presses and planking.
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.