This is a term used by many dietitians and nutritionists often, but what does it really mean? First, we need to review what a calorie actually is.
Calories are not bad things, truly. Once you realize that, your relationship with food instantly improves. A kilocalorie, or to us just a calorie, is a measurement of energy. That's correct- calories are not actually a measurement of shame or disgust, but of fuel. Every living thing expends energy and needs energy to survive. Just as a car cannot run off a AA battery but a potato can illuminate a bulb, there is a balance of energy that needs to happen for a body to function at its best. The more you move and the larger you are, the more energy you need.
In high school, my best friend was a swimmer. He was incredibly fit and around 6 feet tall. I remember watching in awe as he would pack a lunch and snacks for throughout the school day, in addition to getting a school lunch. He told me at that time that he needed to consume a minimum of 6,000 calories a day. I was fascinated! But my friend was swimming for hours every night, training to be able to sprint, while competing in peak condition. If I had chosen to join him in his high calorie meals, I would have gained significant weight very quickly.
We know that 3500 calories equals 1 pound of human body fat. Therefore, if a person simply ate 100 calories more each day than their daily need, in theory they would gain over 10 pounds in a year! As we all know from 100 calorie pack snacks, 100 calories is not a lot to overeat and can easily be done. It's probably eye-opening also to see now how easy it is to gain a few pounds over the holidays, but difficult to lose it afterwards in the cold! My swimmer friend was able to eat 6000 calories a day because he was using 6000 calories worth of energy consistently, therefore not needing to store the energy for later.
How can you know how much fuel your body needs? There is a simple formula that dietitians use called Basal Metabolic Rate (BMR). This gives you a ballpark average to shoot for that only takes into account your current height, weight, sex, and age. BMR is the estimate of the amount of energy that your body would need to function properly if you only lie in bed all day long, without moving. You can use a BMR calculator online to find this number easily, without doing any math yourself. After finding that base number, you can multiply by another rate that takes into account your physical activity to give you a good starting point of how many calories you need in a day to stay fit.
Now that we fully understand what calories are and know how to find out how many we need in a day, let's circle back to what it means for calories to be "empty".
Any food with protein, carbohydrate, or fat contains calories. They are the three categories of nutrients that provide energy. We know that saturated fats (those that are usually solid at room temperature) and sugar are needed in very small quantities, even though they are very tasty to an addicting level. Foods that are high in calorie but contain no significant nutritional value outside of saturated fat and/or sugar are not providing any "nutritional bang for the calorie buck", if you will. Both of these ingredients in high quantities have been linked to higher risk of cancers, heart problems, diabetes, dementia, and kidney failure. Foods that fall into this category are fast food, regular soda, candy, pastries, creams, potato chips, and alcoholic beverages. When wondering if a food contains a lot of empty calories, check out the nutrition fact label to see the saturated fat and sugar content.
It's not that you can't indulge in a treat every now and then. Sometimes it is nice to have a slice of cake at a birthday party, a beer at a ball game, or an alfredo dish! Just remember that you simply can't run on empty all the time.