The consumption of carbonated drinks is discouraged after weight loss surgery. In fact, there is a wealth of information that documents the detrimental health effects of carbonated drinks for each individual. These include osteoporosis, obesity, and premature dental decay, just to name a few. Indirectly, carbonated drinks have been found to increase risk of stroke and Cardiac events. There are studies that show a 48% increase in heart attack and stroke rates for individuals who drink diet sodas vs. those who drink it rarely or not at all.
There is also no health benefit to diet carbonated drinks. In fact, there are animal studies that show that rats who consume no-calorie sweeteners found in diet sodas experience an increased appetite (Susan Swithers, PhD- 2004).
There are also other factors to consider. The carbonation comes from a mixture of dissolved gasses that are released when the container is opened. The Carbon Dioxide gas dissolved in the drinks, amongst others, can distend the stomach. Potentially, stretching your stomach. There is also acidity that needs to be corrected by the body. This has been shown to result in changes in the bacterial population in the GI track, resulting in significant bloating and reduced absorption of nutrients.
Calcium loss is caused by the leaching of the calcium from the bones with carbonated drinks, which can cause osteoporosis.