Know Your Numbers

From: Eating Supportively

Nutritional Targets: So what are these targets? Well, it can be different depending on who you ask. Let's start with some basics: Protein contains 4 calories per gram and it is recommended that approximately 10-35% of your daily calories come from protein. Carbohydrates also contain 4 calories per gram and comes from fruits, vegetables, and whole grains, and it is recommended that approximately 45-65% of your daily calories come from carbohydrates. Fats contain 9 calories per gram and it is recommended that approximately 20-35% of your daily calories come from fat (less than 10% from saturated fats and the majority from polyunsaturated and monounsaturated fats).

The next piece of the puzzle is determining your specific resting metabolic rate (RMR) which represents the number of calories it takes to fuel your body (ventilation, blood circulation, temperature regulation, digestion, etc.). The Mifflin-St. Jeor equation is the most accurate estimation of RMR and is outlined below. Some info you need to know to complete the formula are your weight in kilograms (1kg=2.2 lbs and you can easily convert by dividing pounds by 2.2), your height in centimeters (1 inch=2.54 cm and you can easily convert by multiplying inches by 2.54).

For men: RMR = 9.99 x wt(kg) + 6.25 x ht(cm) - 4.92 x age(yrs) + 5
For women: RMR = 9.99 x wt(kg) + 6.25 x ht(cm) - 4.92 x age(yrs) - 161

The RMR value derived from the predication equation is then multiplied by the appropriate activity correction factor below to determine your total daily energy expenditure (TDEE). Note that this equation is more accurate for obese than non-obese individuals.

*Sedentary (little or no exercise): 1.200
*Lightly active (light exercise/sports one to three days per week): 1.375
*Moderately active (moderate exercise/sports six to seven days per week): 1.550 (if you workout with me this is the calculator you would use)
*Very active (hard exercise/sports six to seven days per week): 1.725
*Extra active (very hard exercise/sports and physical job): 1.900

Example:
For a moderately active 38 year old 140 lb 5'6" female then;
weight in kg = 64 (140/2.2)
height in cm = 168 (66 x 2.54)
RMR = 1,341 ((9.99 x 64) + (6.25 x 168) - (4.92 x 38) - 161)
TDEE = 2,079 (1,341 x 1.550)

The Dietary Guidelines recommend that those trying to lose weight aim for a 500 calorie deficit per day, achieved through decreased calorie intake and/or increased physical activity. Even for fat loss you would take the above derived number and decrease it by 500 for your total daily caloric total. From there you can break out the particular nutritional targets: protein, carbohydrates, and fat based on the previously provided information.

Example:
If your TDEE is 2,079 then your total daily caloric intake should be 1,579 (2,079 - 500) then;
Protein would be 474 calories and 118 grams (1,579 x 30% / 4)
Carbohydrates would be 711 calories and 178 grams (1,579 x 45% / 4)
Fats would be 395 calories and 44 grams (1,579 x 25% / 9)

Be sure to reevaluate your nutritional targets about every 5 to 10 pounds lost.