What’s a calorie anyway?

Written by Dr. Linda Kennedy

Whenever the topic of weight-watching or dieting comes up, one inevitably hears about calories. This in understandable as, all other things being equal, the balance between calorie intake and consumption is what determines whether your can maintain your ideal weight. Caloric values can be found on the labels of food products. Some cookbooks as well as the menus of some health-conscious restaurants list the calorie content of their foods along with their ingredients, but these are very few and far between. Caloric values can also be found on nutritional products such as vitamin pills, liquid vitamins and other whole food supplements. But what exactly is a calorie? Where do calories come from? How many calories do you need? And most importantly, how can you attain your ideal physique by being calorie conscious?

What’s a calorie?

In physics, there are various forms of energy, such as light and heat. Simply put, a calorie is a unit of heat defined as the amount of energy needed to raise the temperature of 1 gram of water by 1 degree Celsius. Food calories are measured in kilocalories. That means that the 1 calorie found in your diet soda can be transformed into enough heat energy to raise by 1 degree Celsius the temperature of 1 kilogram of water, which is equivalent to 1 litre.

Where do calories come from?

Fruits and Vegetables

All food products digestible by the body are in the form of carbohydrates, fats, or proteins. These 3 types of nutrients can be metabolized by the body to produce energy. Proteins and carbohydrates can produce 4 calories per gram. Fats are more energy-dense foods: they can produce 9 calories per gram. All the energy from our food is either used by the cells of our body for normal functioning or to build more tissue. Protein in our diet can be used to build new muscle. Alternatively, any excess energy is stored for later use, mainly in the form of adipose (or fatty) tissue.

How many calories do you need?

The human body requires a certain amount of calories per day to function properly. An average-sized adult male requires around 2500 calories a day. An average-sized non-pregnant woman needs less, around 2000 calories per day. These figures can vary greatly depending on a number of factors. Changes in environmental temperature, increased core body temperature, and increased level of physical activity, among other things, increase the caloric requirements of the body. Children and the elderly typically require less energy daily. Calories are normally obtained from the food that we eat. However, the body can also obtain calories from nutrients derived from the body’s own stores of energy, and even from the breakdown of muscle.

How can you attain your ideal physique?

Measuring Tape

Now that you understand what a calorie is and how it affects your body, we can begin to understand how our body weight is affected by your calorie intake. Given that our body has a daily calorie requirement for everyday activities, then anything in excess of that gets stored within the body. If there is no muscle tissue to repair as the result of a lack of exercise, excess calories are stored as fat and glycogen. This last is the storage form for carbohydrates in the human body. Carbohydrates can be consumed in their simple form – namely bread, cereals and pasta – or in their complex form- namely phytonutrients rich foods such as fruits and vegetables.

The most abundant form of energy stores in the human body is fatty tissue. Because 1 gram of fat releases 9 calories of energy, this makes fat the most ideal form for storing energy. Fats can be taken in both as meat products and oils used for cooking. Most of the excess calories in the diet, beyond what is needed by daily calorie requirements, are converted into adipose tissue. This is referred to as calorie surplus or calorie excess. As the body accumulates adipose tissue, excess weight is gained. If the energy stored as fatty tissue is not used, or if the diet contains more calories than needed, weight simply continues to increase.

On the other hand, if you need to lose weight, the fat stores of the body need to be utilized for energy. Weight loss happens when the body experiences what is referred to as a calorie deficit. If one decreases the amount of calories required by the body, or decreases the daily calorie intake, the result is weight loss. This gives you two ways in which to lose weight: reducing  the amount of calories consumed a day or increasing the calories required a day. Both will lead to a calorie deficit.

Exercise Ball Crunches

The best way to increase the daily caloric requirement of the body is through exercise. Most exercise falls into two general types: cardiovascular exercise and muscle-building exercise. Both types of exercise increase the calorie requirement of the body. Cardiovascular exercise usually entails prolonged periods of exertion. Heart rate and respiratory rate are increased to meet the metabolic demands of the body because of the use of muscles for movement. Fat stores are then decreased as more calories are required by the body to meet these metabolic demands. More intense exercise that uses more muscle groups will require more calories.

Muscle-building exercises like weightlifting do not last as long and do not require as many calories as cardiovascular exercise. This is due to the fact that fewer muscle groups at a time are being used and only for shorter periods of time. However, in the long run, muscle-building exercise induces the same amount of calorie burn as cardiovascular exercise since the former increases the muscle mass of the body. Larger muscle mass increases the daily calorie requirement of the body.

In conclusion

Calories are not a bad. They are required in adequate amount so that the body and mind can function properly. However, as with everything else, excess calories are detrimental to health and wellness. Excess caloric intake turns into fat moving one further away from his ideal body. Carrying excess weight makes one prone to diseases such as diabetes, heart disease and even cancer. With a balanced diet and adequate exercise, one will be able to shed excess weight by reducing the calories stored in the body.