The phrase "fewer calories" refers to a reduced amount or number of calories in something. Calories are a measure of energy that our bodies receive from food and drinks, and they play an important role in maintaining our weight, growth, and overall health. When we consume fewer calories than we burn through physical activity or basal metabolism, we lose weight. Conversely, when we consume more calories than we need, we gain weight. Therefore, "fewer calories" means a lower number of calories in the foods or beverages that we eat and drink to maintain our energy needs while controlling our body weight.