Gulping down sugary sodas can lead to unwanted weight gain, according to Dr. Jo Ann Carson, an associate professor of clinical nutrition at UT Southwestern Medical Center at Dallas. “By adding one can of soda daily to your otherwise healthy regimen, you could theoretically gain 15 pounds in a year’s time,” said Carson. The average 12-ounce can of soda contains 150 calories. Americans are consuming twice as much soda as they did 25 years ago, and as the serving sizes of soda containers continue to increase, so will the number of calories. Caffeine-free diet sodas, vegetable juices and sugarless ice teas are healthy alternatives to calorie-laden sodas. “Water with a bit of lemon is also a great choice,” Carson said.