Welcome to Common Core Texts, a project by Michael DeJoseph. Here you'll find high-quality reading passages for grades 3 to 12 in ELA, Social Studies, History, Science, Technology, Engineering and Math (STEM) and many other topics.

Counting Calories
A Reading Comprehension Passage by Common Core Texts

On the back of every packaged food item sold at your local grocery store is a label containing nutritional information. The very first number on this label tells customers the number of calories that the food contains. An important component of healthy eating is paying attention to this “calorie count.” Most people know that calories tell us how much of a food we should eat. But did you know that a calorie count is not a measurement of fat, nutrition, or vitamins? It is actually a measurement of energy.

All physical matter contains energy, and food is no exception. The energy contained in our food is what fuels our bodies, keeping us active and energized. But how do scientists measure the number of calories contained within food? The answer is simple: they burn it! When food is burned, it produces heat. The more energy contained within the food, the more heat is given off. For example, oils and other fats are high in energy. When they are burned, they give off a lot of heat. Lower-energy nutrients such as carbohydrates and protein give off less heat. That is why foods containing fats have a higher calorie count than foods containing carbohydrates or protein.

In order to measure the heat given off by food, scientists use a device called a calorimeter. A calorimeter has a sealed chamber containing food. This sealed chamber is surrounded by water. Using electricity, the food is burned. This causes the chamber to heat up, warming the water surrounding it. A thermometer can then be used to measure the change in water temperature.

Leave a Reply