1. If you pick up any health or fitness magazine, you’ll likely see an array of diet and calorie
recommendations, most of which are designed for weight loss. Some say 1200 per day. Another
may say 1500 per day. So, how much is enough? Calories come from all the different foods and
beverages we consume and provide energy for our bodies. The energy in food is measured in
kilocalories (Kcal), also known as Calories (C). However, it is common practice in non-scientific
writing to use the term "calorie," with a lowercase c, when discussing the energy value of food.
Estimating Calorie
and Nutrient Needs

2. When you see the term "calorie" in relation to diet and nutrition, it refers to the kilocalorie.
Both calorie and kilocalorie are units of energy. To be precise:
1 calorie = the amount of energy (heat) needed to raise 1 gram of water 1 degree Celsius. 1
kilocalorie (Calorie) = the amount of energy (heat) needed to raise 1 kilogram of water 1 degree
Celsius.
The fat in the foods we eat provides 9 calories per gram, alcohol provides 7 calories per gram
and carbohydrate and protein each provide 4 calories per gram. This is why many health
professionals recommend cutting back on fat and empty calories from sugar or alcohol to aid in
weight loss.
Reducing fat, and sugar and alcohol intake may also reduce risk of heart disease, diabetes and
certain cancers. The type of fat you consume does make a difference. For example, olive and
canola oil are heart-healthy, while saturate and trans fat and detrimental. However, both types
of fat still contain the same amount of calories per gram.
The calories (or energy) we consume from food are needed for breathing, metabolizing and
absorbing nutrients, maintaining body temperature, thinking and other physiologic functions,
including exercise. To maintain body weight, calories you consume must equal calories you
burn (through normal bodily functions and/or exercise). When excess calories are eaten and
not burned up by the body, the extra calories are stored as fat and result in weight gain. When
fewer calories are eaten than are burned, weight loss is the result.
You can estimate calorie requirements through a variety of formulas that are based on a
person's:
? Height
? Weight
? Age
? Sex
? Activity level
Therefore, everyone's calorie requirements are different. In general, most individuals need a
minimum of 1200 calories per day to maintain normal physiological functions. If you consume
less than this, your body may feel as though it is ?starving? and will lower your metabolism. You
will also likely not consume enough calories to meet the RDAs for most nutrients. Very low
calorie diets are not advised, though may be used by medical weight loss centers that are
monitored by medical personnel.
How to Calculate Energy Needs

3. Resting Metabolic Rate (RMR) A common formula used to estimate calorie needs is called the
Mifflin-St. Jeor Equation (named after the scientists that developed it). It is used to determine a
person's RMR (metabolic rate). This represents the amount of energy (calories) the person uses
for basic bodily processes, such as breathing and maintaining blood pressure. The RMR does
not take into account a person?s physical activity.
The formula is as follows:
Men: RMR= 5+10 (weight in kgs) + 6.25 (height in cms) ? 5 (age in years)
Woman: RMR= 161+10 (weight in kgs) + 6.25 (height in cms)- 5 (age in years)
Total Energy Expenditure (TEE) Your TEE, or total energy expenditure, is your RMR multiplied by
an activity factor. This is the amount of energy you use during a normal day, including calories
for physical activity. To put this in context, your RMR reflects the calories you need to carry out
normal bodily functions such as breathing and maintaining body temperature. Your TEE takes
into account how active you are. Are you a couch potato, or a marathon runner?
The TEE takes into account the extra calories your body needs to keep up with your daily
activity. Exercise is the most variable way to adjust calorie needs. The more physically active
you are, the more calories your body requires to maintain or gain weight. The following
exercise factors are used in calculating your calorie needs for weight maintenance:
? 1.200 = sedentary (little or no exercise)
? 1.375 = lightly active (light exercise/sports 1-3 days/week)
? 1.550 = moderately active (moderate exercise/sports 3-5 days/week)
? 1.725 = very active (hard exercise/sports 6-7 days a week)
? 1.900 = extra active (very hard exercise/sports and physical job)
Decreasing your physical activity level, or consuming more calories than your daily TEE will lead
to weight gain. Increasing your activity level, or eating fewer calories than your body needs, will
lead to weight loss. To lose 1 pound of weight per week, subtract 500 calories per day from
your TEE. For example, if your maintenance needs are 2000 calories/day, you would need to
limit your intake to 1500 calories per day to lose.