The typical US diet includes almost 20% of calories from beverages. Thus, the substitution of plain water, either in part or even entirely, as the primary drink is a simple, scalable, inexpensive way to reduce mean calorie intake by up to 200 calories/day, assuming a 2000 calorie diet. Observational data support the concept that increasing plain water intake is associated with reduced calorie consumption. Sugar-sweetened beverages (SSBs) should be limited or avoided because of strong associations with abdominal obesity and type 2 diabetes. Artificially sweetened beverages may be safer than sugar-sweetened beverages but less desirable than plain water.