Calculating YourDaily Calories

Ever wonder how nutritionists

or personal trainers are able totell you exactly how many

caloriesyou need to lose the extra weightyou put on over the holidays, or to gainthe muscle mass you have been strivingfor? Well, there are various methods

health professionalsuse to estimate yourdaily calorie needs. Let's first discusswh~t elements comprise your caloriereq~irements and then discuss how youca~ estimate your needs.

Yourdaily energy needs (caloric require-ment) are determined by three factors.These are your resting metabolic rate(RMR), thermogenesis (caloriesrequiredfor heat produCtion),and physicalactivity.Yourresting metabolic rate is, essentially,the amount of energy (measured incalories) expended by the body duringquiet rest.

Your RMR makes up between 60 and75% of the total amount of caloriesyouuse daily. Physical activity is the secondlargest factor contributing to your dailycalorie requirements. This is the mostvariable component of RMR, as thisnumber changes based on the frequency,intensity,and duration of your workouts.Thermogenesis, also referred to as thethermic effect of food, is the smallest

component. This is the amount of caloriesneeded to digest and absorb the foods

you eat. While certain diets claim toenhance this component (e.g. foodcombining programs), no researchexiststo support that concept. The bottomline is that regularphysical activity is thebest way to make a huge impact on yourcalorie needs.

Calculating YourEnergyNeedsThere are numerous ways to calculateyour daily calorie needs. For a simplemethod, refer to the chart below and

multiply your weight (in pounds) by theconversion factor.

Estimating Your DailyCalorie NeedsMultiply your weight (in pounds) by theconversion factor listed below. This will

giveyou an approximation of how manycalories your body needs to maintain itscurrent weight, based on your activityleveland gender. To lose or gain weight,see the section below.

Another method, which takes into your

account your weight, height, age, andgender, but requires some calculations isprovided below.

Use the following equation and plug inyour weight (kg), height (cm), and age(years) in the following formula:

Males:

66 + (13.7 x Weight)+ (5 x Height)- (6.8x Age)

Females:

655 + (9.6 x Weight)+ (1.7 x Height)- (4.7xAge)

Note:.To determine weight in kg:divide weight in Ib/2.2.To determine height in cm:multiply height in inches x 2.54

Table 1. Conversionfactors for estimating daily caloric requirements based ongender and activity level.

* Light activity level: walking (level surface, 2.5 - 3.0 mph), housecleaning, child care, gol£

Moderate activity level: walking at 3.5 - 4.0 mph, cycling, skiing, tennis, dancing.

Heavy activity level: Walking with load uphill, basketball, climbing, football, soccer'.

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To this, you must add an activity factorbetween 1.2 and 1.5 to account for youraverageamount of physical activity'.

. 1.2 bed rest

. 1.3sedentary

. 1.4active

. 1.5 very active.

I know my calorie needs,how does this affect myweight?Once youhavean estimateofhowmanycalories you need daily, you must thendecide if you are trying to lose, gain, ormaintain weight. In order to changeyourweight by one pound, you must increase(to gain) or decrease(to lose)your intakeby 3500 calories. For weight loss, it isad~isable to reduce your daily caloricintake by 250 calories per day (to loseone pound per week) and to increaseyour daily expenditure (through exercise)by 250 calories.This 500 Calorie differ-ence, when multiplied by 7 (days in oneweek)will allowyou to offsetyour caloricbalanceand resultin one pound of weightloss. Double these numbers if you aretrying to lose 2 pounds per week. Mosthealth organizationsrecommend a weightloss rate of 1 - 2 pounds per week.

To gain weight, add 300 - 500 caloriesto your daily intake in order to promotea weight gain of up to one pound perweek. Be sure to continue your exerciseroutine so that the additional caloriescan be used to fuel muscles, rather than

simply store additional fat. Follow yournew calorie plan for a few months andmakechangesas needed....

References1. BaechleTR, Earle RW (Eds.). (2004).

Essentials of Strength Training andConditioning (2nded.). Champaign, IL:Human Kinetics.

2. Roitman J (Ed). (2001). ACSMs&source Manual: For Guidelines forExerciseTestingand Prescription(4° ed.).Philadelphia: Lippincott, Williams andWilkins.

About the AuthorDebra Wein,MS, RD, LDN, NSCA-CPT,

is a faculty member at the UniversityofMassachusetts Boston and teachesgraduate

nutrition coursesat Simmons College. She

is the President of The Sensible NutritionConnection, Inc. (www.sensiblenutrition.com).

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