Just because there are less calories in a particular food, does not mean that it is necessarily better for you or your diet. Often, less nutritious foods will have less calories, but will also have less nutrients.
Low calorie foods can also leave you feeling hungry and empty. This will ultimately lead you to having more cravings for unhealthy foods.
Zero calorie drinks are good for dieting
Just because a drink does not contain any calories, does not mean that it will not have any effect on your body. Often, zero calorie drinks will contain carbohydrates, which are processed by your body and, if not used, stored as fat.
When a flavored beverage has zero calories, it most likely has artificial colors, flavors and preservatives that can be worse for you than consuming a full-calorie drink. Your body cannot process most artificial sweeteners and they are stored as the dangerous fat around your vital organs.
A calorie is a calorie
Not all calories are created equal. Calories can come from carbohydrates, fats or proteins and each of these nutrient groups are processed differently by the body.
For example, consuming 100 calories in sugar (simple carbohydrate) will have extremely different outcomes to consuming 100 calories in chicken (protein).