Think you’ve got your diet under control? You may be gulping down hundreds of unwanted calories without even knowing it.

“Believe it or not, more than 20 percent of our daily calories come from the things that we drink,” says Susan Aaronson, M.S., R.D., wellness coordinator for the M-Fit Health Promotion Division at the University of Michigan Health System. “In fact, the World Health Organization recommends that people consume only about 10 percent of their calories from liquids. So those extra calories from liquid beverages are adding to American’s obesity epidemic, making it more difficult for people to lose weight.”

According to the National Health and Nutrition Examination Survey, about 136.5 million Americans are overweight. Of these people, about 64 million are obese.

And for the millions of Americans who are trying to lose that extra weight, the solution may not be in what you eat, but what you drink, says Aaronson. To help you make healthier beverage choices -  from soda and sports drinks to fruit juice and milk -  and cut back on calories, Aaronson offers the following tips.

Soda
“Soda is full of sugar and empty calories, making it a major contributor to the obesity problem in the United States,” says Aaronson. “If you chose to eliminate one can of soda each day, which contains about nine teaspoons of sugar, you can lose about a pound in one month; and over the course of a year, you can lose up to 15 lbs.”

And since it has no nutritional value, filling up on soda also prevents you from getting calories from sources that do contain essential vitamin and minerals. But if you absolutely can’t live without a soda, Aaronson instead recommends drinking diet soda, or reserving it only for special occasions.

Fruit and vegetable juices
Are you drinking ‘fruit juice’ or some beverage labeled ‘fruit drink’? The difference can mean extra calories and few nutrients, says Aaronson.

“Read the label carefully,” cautions Aaronson. “If a juice label says that it’s ‘made with real fruit juice’, it may actually contain less than 10 percent of ‘real’ juice and about seven teaspoons of sugar. The best juice drinks to pick are those that say they contain ‘100 percent juice.’”

Parents should be particularly vigilant about how many juice boxes they allow their kids to drink each day. Just one juice box contains 100 calories, and four of them are equal to about a quarter of the amount of calories a child should consume in one day.

Aaronson recommends limiting yourself to one serving, or five ounces, of juice a day. The rest of your daily servings of fruits and vegetables should come from actual pieces of fruits and vegetables. Real fruits and vegetables contain the daily fiber your body needs that you won’t find in fruit drinks.

Milk
Choosing low-fat milks can help you save hundreds of calories each day, says Aaronson.

Milk also contains vital nutrients like calcium, protein, vitamin D, and vitamin A that you won’t find in other beverages. Plus, it is recommended that you get three servings of dairy every day.

To get the most from your milk, Aaronson says to choose 1 percent, 1/2 percent, or skim milk. With these options, you will still get all the nutrients your body needs but without the extra calories and fat.

Sports drinks and energy drinks
Although sports drinks replenish your body with electrolytes that help you retain water and stay hydrated, they still contain a lot of calories -  one-half to one-third the amount of sugar you’ll find in soda.

“Sports drinks were actually developed for endurance athletes,” explains Aaronson. “So if you plan to exercise for more than one continuous hour, then sports drinks are for you.”

And you won’t find a lot of nutritional value in energy drinks, either, notes Aaronson.

“Energy drinks are not only loaded with calories, but they’ll give you a quick high, followed by an extremely-low low afterward,” explains Aaronson.

Alcohol
If you are planning an evening of dinner and drinks, remember that you could have the calorie-equivalent to a whole meal in drinks only, before you’ve eaten anything at all.

The average glass of wine has about 100 calories and a 12 oz. beer contains approximately 150 calories.

According to Aaronson, it’s not uncommon for a mixed drink to have about 300 calories and the decadent frozen drinks like daiquiris to have 500 or more calories each. So limiting the number and types of drinks you have before eating will make a major difference for your waistline.

Water
So what is the ideal beverage to quench your thirst? It’s the colorless, odorless, and tasteless refresher that makes up over half of our body mass: Water.

“Water is the single most important beverage that we can consume,” says Aaronson. “A person could drink only water and be just fine, as long as he supplements his diet with food sources that contain calcium and other nutrients that one may find in other beverages such as milk and juice.”

In general, 80 percent of a person’s liquid calories should come from water depending on their height, weight, and where they live. That means the average adult should drink between 4 and 6 cups of water a day, which should be supplemented with milk and 100 percent juice to meet total daily liquid requirements.

Another option is flavored water that is fortified with vitamins. But Aaronson says if you’re already eating a healthy diet, there’s no reason to drink vitamins in the form of water.

The bottom line: “The next time you think about digging into the fridge for a soda, save yourself the money and the calories and reach for the tap instead,” says Aaronson.

University of Michigan Health System