Soda and carbonated soft drinks -- two names for the same beverage -- consist mostly of water, which means they help keep you hydrated. But sodas don’t nourish your body, and if they're sweetened with sugar, the calories add up quickly. All types of soda, including diet soda, contain ingredients that may weaken bones or cause tooth decay.
Contribute to Hydration
Even caffeinated sodas help you stay hydrated. All beverages, except alcohol, contribute to your daily water needs. Caffeine slightly increases elimination of fluids through urine, but not enough to cause dehydration.
Limit sugar-sweetened soda to no more than 8 ounces daily and keep diet soda consumption to 16 ounces or less, recommends the Harvard School of Public Health.
Even though caffeine isn't dehydrating, it's still best to limit daily caffeine intake to fewer than 300 milligrams, reports Family Doctor. One cup of a caffeinated cola has 22 milligrams.
Health Risks From Sugar
The large amount of sugar added to soda represents a significant health risk. Sugar-sweetened soda is high in calories that cause weight gain. Drinking sugar-sweetened soft drinks is associated with a higher risk of type-2 diabetes and cardiovascular disease, according to an April 2014 report in Diabetes Care.
One cup of sugar-sweetened cola has 101 calories and the equivalent of nearly 7 teaspoons of sugar. And that’s just an 8-ounce serving. A can of soda is 12 ounces, and a large fast-food serving jumps up to 32 ounces, which has 403 calories and 26 teaspoons of sugar.
Impact on Bones
Many sodas contain phosphoric acid, which may weaken bones. The body strictly regulates the amount of calcium and phosphate in the bloodstream. This balance is disrupted if you consume more phosphorus than calcium, which is easy to do by drinking too much soda. When levels of phosphorus in the bloodstream are higher than calcium, the body pulls calcium out of the bones to restore balance.
Consuming a large amount of caffeine may affect bones because caffeine can interfere with calcium absorption. But you'd have to drink about 10 caffeinated sodas daily to worry about that risk.
Acids Damage Teeth
You can dodge sugar consumption by drinking diet soda, but most sodas contain phosphoric acid or citric acid. As a result, soda is acidic enough to erode tooth enamel. Sodas are more acidic than fruit juices, and the level of acidity in diet cola is about equal to a regular cola, according to a study in Nutrition Research in 2008.
Tips for Cutting Back
Whether you start small and gradually reduce, or cut out all soda at once, the most important thing is sticking with your goal. After deciding how many cans of soda to eliminate daily, choose replacement beverages and stock the pantry. At the same time, stock less soda so it’s not easily available.
Sparkling water with a dash of juice, water and plain tea and coffee are alternatives recommended by the Harvard School of Public Health. Fruit and vegetable juices are options that provide vitamins and minerals, though they're still high in sugar, lack beneficial fiber and are often acidic enough to contribute to tooth decay. Watch for sodium content in vegetable juice, and go with 100 percent fruit juice to keep sugar and calories down.