Calories: Why do I need them?

When we talk about how much energy our bodies need throughout our day, we first need to understand what energy is. We gain energy from our diets through the consumption of carbohydrates, fats, proteins, and alcohol (in moderation). When these nutrients are consumed, our bodies digest, absorb, metabolize and either use the energy immediately or store it until it is needed for movement or exercise. A more commonly known word for energy measurement within the body is Calorie (or kilocalorie).

Although Calories often get a bad reputation for being the cause of weight gain, it is important to remember that we need Calories to live and function. It is however more important that we find ways to balance how many Calories that we consume a day to that in which we need per day in order to control fluctuations in weight and energy levels. As healthy active individuals we should think of Calories as our energy needed for our daily living tasks and energy necessary for optimal performance during exercise.

So you may be wondering, “How many Calories do I need then?” This is a tough question to answer because there are many different factors that influence energy balance for each individual. Some common factors that affect energy balance are:

• Age
• Gender
• Body Composition
• Metabolic Rate
• Tissue Growth
• Intensity and Duration of Activity

Some general recommendations for Caloric intake have been made and consensus among researchers show that the amounts needed can be categorized into four separate groups of individuals and their requirements. Below is a table that shows the different groups and the recommendations that have been given to each.

Group	Requirements	Example**
Sedentary Men and Non-Pregnant Women	Approximately 31 Calories / kg* of Body Weight	60kg x 31= 1860 kcal
Male and Non-Pregnant Female Recreational Athletes	Approximately 33-38 Calories / kg* of Body Weight	(Low End) 60kg x 33= 1980 kcal (High End) 60kg x 38= 2280 kcal
Endurance-Trained Athletes	Approximately 35-50+ Calories / kg* of Body Weight. Needs vary depending on specific sport and training regime.	(Low End) 60kg x 35=  2100 (High End) 60kg x 50= 3000 kcal
Strength-Trained Athletes	Approximately 30-60 Calories / kg* of Body Weight. Needs vary depending on specific sport and training regime.	(Low End) 60kg x 30= 1800 kcal (High End) 60kg x 60= 3600 kcal

*  To convert weight from pounds to kilograms, divide weight by 2.2.

**Example 132lbs / 2.2 = 60kg

Individuals who continually consume too little Calories often do not consume enough nutrients which in turn can cause a decrease in performance and overall energy levels. If low-Caloric, low-nutrient diets put the individual at risk for muscle and bone mass loss, inability to gain muscle or bone mass, fatigue, illness, menstrual changes, and injury. For those who need to maintain a restricted Calorie diet should work closely with a professional dietician to plan nutrient-rich, low Calorie diets that will enhance their training performance while achieving training goals.

Blog post by Craig Moody.