The term “calorie” is typically only used in a negative context, but, objectively, calories are just energy. They’re the fuel that our bodies require to function. Much discussion occurs related to consuming more calories than our bodies need, but it’s important to understand that our bodies do still require a minimum amount of this energy. In certain eating disorders, particularly anorexia and ARFID, calories may be significantly deficient.
Many clients I talk to are surprised to learn just how much energy is necessary to support basic metabolic functions on a daily basis. By “basic,” I mean that your body needs this amount of energy if you did absolutely nothing all day, literally not even getting out of bed. As an example, here’s an estimate of these basic, minimum energy needs for a 30-year-old woman who is 5’4” and weighs 125 pounds:
· Liver: 400 calories
· Brain: 270 calories
· Heart: 130 calories
· Lungs: 115 calories
· Kidneys: 90 calories
· Other basic functions: 270 calories
This adds up to around 1275 calories per day. Remember, this doesn’t account for any physical activity whatsoever, any of which will increase energy needs.
Think about all the trendy diets and apps that promote calorie intake below this number. With few exceptions, daily calorie intakes of 1200 calories or less are unsustainable and counter-productive. A calorie deficit of this magnitude – which may be amplified by excessive physical activity with an eating disorder – leaves essential functions of the liver, brain, and heart running on empty.
Our energy needs are individual, and myths and misinformation about calories are everywhere. A dietitian may be able to help you better understand the reality of your energy needs, and get you on the right track to fueling properly.