1 kcal = 1 large calorie. So 4.5 kcal/lb per day * 10 lb = 45 large calories per day, not 450. > The small calorie or gram calorie was defined as the amount o

1 kcal = 1 large calorie. So 4.5 kcal/lb per day * 10 lb = 45 large calories per day, not 450. > The small calorie or gram calorie was defined as the amount of heat needed to cause the same increase in one gram of water. Thus, 1 large calorie is equal to 1000 small calories. > In nutrition and food science, the term calorie and the symbol cal almost always refers to the large unit. It is generally used in publications and package labels to express the energy value of foods in per serving or per weight, recommended dietary caloric intake, metabolic rates, etc. Some authors recommend the spelling Calorie and the symbol Cal (both with a capital C) to avoid confusion; however, this convention is often ignored. > In physics and chemistry the word calorie and its symbol usually refer to the small unit; the large one being called kilocalorie. https://en.wikipedia.org/wiki/Calorie https://en.wikipedia.org/wiki/Calorie