Big Soda has agreed to go on a diet and scale back the calories in its sugary drinks.

A consortium formed by the American Beverage Association, Coca-Cola (KO), Dr. Pepper Snapple Group (DPS) and PepsiCo (PEP), has reached an agreement with the Alliance for a Healthier Generation to reduce beverage calories by 20% by 2025.

To accomplish this, the soda industry plans to offer smaller portions of soda and to promote water and other non-calorie or lower- calorie beverages.

Related: Remember Surge soda? It's back

The industry is also planning to launch an education campaign by posting calorie counts and "promote calorie awareness" on 3 million vending machines as well as self-serve fountain dispensers and coolers in stores and restaurants.

Susan Neely, president of the American Beverage Association, called this "the single largest voluntary effort by an industry to help fight obesity."

The Alliance for a Healthier Generation was founded by the American Heart Association and the Clinton Foundation. Former President Bill Clinton said the soda industry consortium "can be a critical step in our ongoing fight against obesity."

Related: Food stamp soda ban can save children from obesity

More than one-third of all U.S. adults are obese, costing the economy nearly $150 billion per year in medical costs, according to the Centers for Disease Control. Obesity can lead to heart disease, stroke, type 2 diabetes and certain types of cancer.

This summer, a study by Stamford University medical researchers showed that banning soda from food stamps would prevent at least 141,000 from getting fat and another 240,000 from getting diabetes.