Understanding the Calorie
The island nation of Yap, located in the Pacific Ocean, is known for its unique currency. On this group of islands, stones are used in commerce (the bigger the stone, the higher the value). Though this seems odd or different compared to our economy in the U.S., an economy forged on the basic building block of the dollar, things are actually quite similar in principal. In fact, this type of organization is common to virtually all countries, organizations, and even organisms. It seems that most everything runs on something as the building block of commerce. For our bodies, this building block is the calorie.
Many of us fight an economic battle with the calorie that often culminates in obesity. In fighting this battle, I have found that a more in-depth understanding of the calorie helps with some of the pitfalls of weight loss. To that end, this blog will examine the calorie as the economic building block of energy in our body.
Science Behind the Calorie
The calorie was first defined by Nicolas Clement in 1824 as a unit of heat. The definition of the calorie is the amount of heat needed to raise one gram of water by one degree Celsius. This unit was primarily used in chemistry and physics and eventually lost favor to the Joule, which is presently the preferred unit. Prior to this change, however, calories were used in the science of the body - nutrition and exercise physiology.
The calorie is still the primary currency when it comes to communicating about energy in the body. As the calorie is a relatively small amount of heat, the kilocalorie (kcal) is the preferred unit. A kcal is the amount of heat required to raise one kilogram (one liter) of water one degree Celsius. It is a simple assumption that the reference to calories is simply, in fact, kilocalories.
Energy In: Nutrition
In 1900, it became U.S. law that any packaged food sold commercially must have the caloric value placed on the label. It still holds that any food purchased in package has the nutrition content and calorie value displayed. Beyond this, many restaurants publish caloric values and there exist cell phone apps and internet sites with this information. Inquiring minds must wonder, however, where this information comes from. Why are some foods higher in calories than others?
The old-school method of measuring calorie content came from submerging the food product in a metal canister and submerging it in water. The food item was burned, and the water temperature was measured for change based on its volume.
New-school techniques measure the content of the basic food building blocks (protein, carbohydrate, fat, and alcohol) and calculate the caloric value. It is a recognized standard that protein and carbohydrates are four kcal per gram, fat is nine kcal per gram, and alcohol is seven kcal per gram. Thus, foods that are higher in fat or alcohol content are higher in calories.
Energy Out: Exercise
We are always using or "burning" calories. Behind the scenes, metabolic processes are occurring such as a beating heart, digestion, and even thinking. We burn different amounts of calories during different parts of the day and with different activities.
While there are many variables to consider, some trends are important. First, everyone has a different resting metabolic rate (RMR). This depends upon body mass (weight) and body composition (muscle vs. fat). A higher weight and higher muscle content both boost the RMR. Typically, while awake, a person's RMR may span between 100 and 200 Calories per hour. This may not sound like a lot, but it adds up significantly, considering every waking hour day to day and week to week. While asleep, the body shuts down a lot of processes, and the caloric burn slows to a rate of 30-80 kcal calories per hour.
Exercise turbo boosts the body's caloric burn. While also dependent on body weight, a person may burn hundreds more calories per hour, depending on the activity. For example, a 185 pound person burns 1100 calories when running for one hour. While some disorders in the body, such as low levels of thyroid or sex hormones, can affect the metabolic rate, for the most part, we're on the same economic scale.
Sorting Our Finances
At the end of the day, the balance between calories eaten and burned can be thought of like a bank account. The tally may amount to a deficit, a surplus, or breaking even. Fat is that bank account. A surplus is stored in fat, while a deficit comes from the stored account, thus causing a shrinking of the fat. In general, there are about 3500 calories in a pound of fat. Therefore, it takes a deficit of 3500 Calories accumulated to lose a pound.
Many of us are working on losing weight, shrinking fat. In finding success, a smarter, more informed approach can turn the tables. Understanding the calorie, the basic unit in the balance of our weight and fat composition, may be the key to help with achieving a successful, healthy weight.