The “calorie” measure used commonly to discuss the energy content of food is actually a kilocalorie or 1000 real calories; this is the amount of energy required to raise one kilogram of water (about 2.2 pounds) one degree Centigrade.

Different foods can be used by the body to produce different amounts of energy – which is why a handful of nuts can have hundreds more calories than a similarly sized piece of lettuce. However, since calories are a measure of energy, there cannot be, as some diet books claim, different “types” of calories. A fat calorie has the same amount of energy as a carbohydrate calorie by definition. It’s just that a gram of nuts has 9 calories compared to 4 calories per gram for carbohydrates and proteins.

A person’s caloric need is determined using a variety of mathematical equations. Age, current weight, desired weight, and height are taken into account. However, there are numerous equations one can use to do this, which many find confusing. And, regardless of which equation you use, each will return similar caloric values. Also, the value of caloric needs you obtain are still an average. This is due to individuality, activity level, BMR (base metabolic rate), current fitness level, gender, and a number of other factors.

What’s an easy way to calculate how much energy/food I need?

One of the simplest methods is based on the Resting Daily Energy Expenditure, RDEE or REE for short. This is the amount of calories you need to intake if you do not exercise. We have also stated this in other areas of the web site so that you will become accustomed to calculating your daily needs.

If you exercise, you must add the number of calories used in the exercise to the following calculation. A list of various exercises and calories burned per duration of exercise are listed in the Burning Fat section under comparisons.

Question: How Many Calories Do I Need Each Day?

Answer:
REE = Body Weight x 10 + 200.

For example, Sam weighs 200 pounds so, REE = 200 x 10 + 200 = 2200 Calories (for days he does not exercise).

Many often ask how much food they should eat. Just remember that food is calories and weight gain is simply a function of energy (food calories) in minus energy out. Following is a rule of thumb, i.e., it is an average and you must adjust it. As a rule of thumb, if you’re gaining weight, reduce caloric intake and if losing weight, add caloric intake. Try 200 Calories per day difference to go one way or the other as a beginning. If you have questions, browse other sections of MyHealthandFitness or contact us.

Energy Balance

This balance is dependent upon energy input and energy output. Both influence energy stores in the body and whether or not we build adipose tissues, i.e., become fat, uh, anorexically challenged!

Think of energy balance this way:

Food Intake – Energy Output = Weight Change.

It’s a very simple concept. If you eat 3000 kcal (common term is calories) per day and only expend about 2000 calories per day because you’re overeating the energy requirements your body needs, e.g. your intake is more than your output, you will gain weight. Someone eating this way would gain about 100 pounds over 12 months. Impossible? No! People have actually done this.

If you eat 100 calories per day more than you need, you will gain 10 pounds during 12 months, on average.

Eating more than you expend, will lead you to a positive energy balance and a weight gain.

If you eat less than you expend, you will be in a negative energy balance and will lose weight.

To maintain your weight, you must expend the same amount of energy that you eat, which will result in no change in weight.

Energy Intake

Energy demands by the body are met by food intake, represented by the numbers of kcal that we eat each day. Determining the appropriate amount of calories and the type of food we should eat to match our energy requirements is a big challenge for a great many of us.

The problem we have currently is that, given ever present supplies of foods, many of us seem to be too successful in attaining the food energy we need. Today, instead of hunting food in the wild, our hunt leads us to the nearest vending machine, drive-up windows, parties, and even office desks where someone always seems to be celebrating something. This really helps us in our quest to overeat and have a fit, trim figure. Also, many of us become junk-food junkies.

How Much is Too Much?

You must match exercise activity to caloric needs. Scientists do this with what we term the resting energy expenditure (REE). Without getting too difficult, let’s use this formula:

Body Weight x 10 + 200 = REE.

It’s an approximation, but works well and will assist you in your initial quest. For example, if you weigh 150 pounds, you would need 1700 kcal daily to maintain your current body weight. This is without exercise.

If you exercise, you will need to determine how many calories you expended during exercise and add that to the above. As an example, suppose you rode a stationary bike for one hour and burned 450 kcal as indicated on the monitor on this device in your gym. You then must add 450 + 1700 = 2150 kcal for this day’s caloric intake. Ah, but this means you’ll have to know how many calories you burned during a given exercise.