"Cal" is an abbreviation of "calorie," which is a unit of measurement used to quantify energy in food and drinks. It tells us how much energy our body gets from consuming a certain amount of food. Full definition
The more low cal meals per week you get, the easier it will be to lose or maintain your weight. (exercise-fitness-nutrition.com)
You should give baby no more than 4 - 6 oz of juice per day (this is roughly equivalent to 1 serving of fruit and this recommendation is based on a baby consuming less than 1600 k / cal per day). (homemade-baby-food-recipes.com)