Drop the sodas, diet or not. Even the no-calorie versions have waist-widening effects: studies have found that diet soda was associated with increased waist size, BMI, and total percentage of fat. One theory as to why this happens is that because diet sodas have no calories, their sweet taste messes with our hormonal systems, and our bodies crave sugar even more than if we had regular soda because our need for sugar hasn’t been satisfied. Replace caloric beverages—including sweetened tea, juices, sugary shakes, coffee drinks, cocktails—with water and you’ll save an average of 200 calories per day. That equates to nearly a pound lost in two weeks just from making one swap.