A Calorie is a unit of energy used to track food intake and exercise. Calories taken in from food is the body's source of fuel and provides it with the building blocks it needs to make new tissues and repair damaged ones. Calories can come from a wide variety of foods some healthy and others not.
Why are calories important?
Calories are important because they will dictate what happens to your weight, which has a huge impact on your overall health. Problems such as strokes, cardiovascular disease and diabetes are closely related to obesity. The relationship between how many calories you eat and how many you burn (your calorie balance) will determine what happens to your body weight.
Whether or not you are actively trying to control your weight, calorie balance has three possibilities: maintaining weight, losing weight and gaining weight. Creating a calorie deficit (burning more than you eat) will cause weight loss. Creating a calorie surplus (eating more than you burn) will cause weight gain. Eating the same amount of calories as you burn will result in your weight remaining unchanged. Your first step in managing your weight, regardless of the goal, is to figure out how many calories your body needs each day. You can use the calorie calculator which takes into account your age, size, gender and physical activity level to come up with an estimation.
Losing weight requires that you create a calorie deficit meaning you need to burn more calories than you eat. If you burn 2,500 calories per day and only eat 2,000, your body has to come up with that 500 calorie difference from somewhere. You can compare this to how your bank account works. If you spend $2,500 each month but only make $2,000, that $500 will have to come from a source other than income, for example your savings account. This will cause your savings account to shrink. That 500 calorie per day deficit will force your body to dip into its energy stores which will cause you to lose weight.
Gaining weight requires that you create a calorie surplus meaning you need to eat more calories than you burn. When you combine a calorie surplus with a strength training routine, your body will use those extra calories to expand muscle tissue which results in gaining weight and strength. Simply eating more without exercise will lead to fat gain.
The premise behind maintaining weight is simple. If you burn the same amount of calories that you eat, your body will neither build up fat stores nor break them down. Your weight will remain the same.
Types of Calories
Though weight is dictated by the number of calories you eat, your overall health is dictated by the types of calories you eat. It's possible to lose weight by eating junk food just as it's possible to gain weight by eating healthy foods.
Fats. Fats are an essential part of a healthy diet. Though some wrongly associate eating fats with gaining unwanted weight, fats do not make you fat, excessive calories do. Fats provide your body with energy and are involved with hormone production and absorption of fat soluble vitamins. There are three types of fats: unsaturated, saturated and trans fat.
Unsaturated fats are known as the healthy fats. They can help lower your cholesterol and decrease your risk for strokes and heart attacks. Sources include mostly non-animal products such as vegetable oils (particularly olive and canola), nuts, seafood and avocados.
Saturated and trans fats are known as the unhealthy fats because they can raise your levels of cholesterol and increase your risk for strokes and cardiovascular disease. Sources of saturated fats include animal products such as dairy, meat and eggs. Sources of trans fats include any food that contains hydrogenated vegetable oils.
Carbohydrates. The public image of carbs has suffered in recent years due to the popularity of low carb diets. These diets preach that cutting carbs will lead to weight loss. The reason that these diets are successful is because cutting carbs out of your diet will lead to a drastic reduction in calories. This calorie reduction is what causes weight loss.
Carbohydrates are the body's main source of energy. All carbs are made up of a certain number of sugar molecules. There are two types of carbs: simple and complex. Simple carbs are made up of only a few sugar molecules while complex carbs are made up of hundreds or even thousands of sugar molecules.
Simple carbohydrates are digested and absorbed into the system a lot quicker than complex carbs. Because of this characteristic, simple carbs can be unhealthy if eaten in large quantities. Simple carbs lead to a large influx of calories into your body in a short period of time. If you don't burn that energy off right away, the body will store it as fat for later use.
Complex carbs are digested and absorbed a lot slower which leads to a more stable release of energy over a longer period of time. They can keep you full for a lot longer than simple carbs which can lead to a lower calorie intake throughout the day.
Simple carbs are not always bad. Before, during and after a workout is the best time to have a meal high in simple carbs. The calories will be absorbed quickly and give your body the energy it needs to workout and recover. Your intake of simple carbs should be limited throughout the rest of the day. Sources of simple carbs include fruit juices, soda, candy, cookies, refined flours (white bread) and other baked goods (cakes, muffins, cup cakes). Sources of complex carbs include vegetables, 100% whole wheat products (bread/pasta), brown rice, beans and legumes.
Proteins. Proteins are the building blocks for tissue in the body. You need protein to grow new tissue (hair, nails) and to repair damaged muscles after a workout. Simply eating more protein will not force your body to make your muscles bigger. Protein can be converted into fat so eating too much protein will make you fat, not muscular.
Proteins are made up of amino acids. A protein can be described based on the types of amino acids it is composed of. The body has the ability to make some of the amino acids on its own. If it can make a certain amino acid, it is called non-essential. If it can't make an amino acid, it's called an essential amino acids. Since the body can't make essential amino acids, they must be taken in through the diet.
Proteins are all made up of different amino acids. If a protein contains all of the essential amino acids it's called a complete protein. If it's missing any of the essential amino acids, it's called an incomplete protein. The body needs all of the essential amino acids to build and repair tissue. You can aid your body in this process by eating a wide variety of proteins. They don't all have to be complete proteins, a wide variety of foods will enable your body to get all of the essential amino acids, even from incomplete sources. Good sources of protein include low-fat dairy, soy, nuts, peanut butter, beans, seafood, eggs and lean meats.
The other side of the calorie balance equation is how much energy you burn. You can increase the amount of calories your body burns through physical activity - exercise. There are two main types of exercise: cardiovascular and strength training. Cardiovascular exercise, or cardio, is any activity that increases your heart rate over an extended period of time, typically 20 minutes or longer. Good examples include running, biking, swimming, playing most sports and circuit training. Strength training is an exercise that puts a load on your muscles causing them to grow. Good examples include weight lifting and body weight exercises (push ups).
Get a free personalized workout routine.
The Bottom Line
The bottom line is that calories not only control your weight but also your overall health. Eating a wide variety of healthy foods, keeping your calorie intake at the appropriate level and exercising on a regular basis will improve your overall health.