How Many Calories Should You Eat?

Eating for fat loss doesn't have to be complicated. In fact, it can become totally intuitive and unconscious fairly quickly if you understand a few basic principles of energy balance and rules of nutrition.

The Body Fat Solution is all about simplicity and the 10 simple nutrition rules that you learn in chapter 6 of The Body Fat Solution book (pp 120-132), are designed to help keep you away from number crunching as much as possible.

By putting yourself into a feedback loop and using results-based thinking, calculating or counting calories becomes optional.

All you need to do is acknowledge the energy balance equation, become aware of your portion sizes and then increase or decrease your portions based on your weekly results (or alternately, adjust your activity level to produce the calorie deficit you need).

However, that doesn't mean calories don't count!

I can't emphasize enough the importance of maintaining a calorie deficit as an absolute requirement of burning fat. If you’re going to track numbers, calories are the most important number to know.

Here are four simple methods to calculate your caloric needs. Depending on whether you’re the analytical type or the “ballpark figure” type, select the method that suits your style the best.

1. The averages method

Use this method if you want a general ballpark estimate and you don’t like math!

For fat loss:
Men: 2100-2500 calories per day
Women: 1400-1800 calories per day

For maintenance:
Men: 2700-2900 calories per day
Women: 2000-2100 calories per day

* NOTE: These are average numbers, so they will be reasonably accurate if your body size or activity level are average. If you are very small-framed and or very sedentary, your calorie needs will be in the lower end of these ranges. If you are very large and or very active, your calories needs will be in the upper end of these ranges or even higher.

2. The quick method

Use this formula if you want a personalized ballpark estimate with one quick calculation. Use the lower number for lightly active, the middle number for moderately active and the higher number for very active.

Fat loss:
10 - 12 calories per lb. of bodyweight

Maintenance:
14 - 16 calories per lb. of bodyweight

3. Harris-Benedict formula

Use this formula for a very accurate estimate of your maintenance level if you know your body weight but not your body fat percentage. For fat loss, create a 20-30% deficit below maintenance.

Note: BMR = basal metabolic rate, which is the amount of energy you require for normal body functions at rest (does not include activity).

Men: BMR = 66 + (13.7 X wt in kg) + (5 X ht in cm) - (6.8 X age in years)
Women: BMR = 655 + (9.6 X wt in kg) + (1.8 X ht in cm) - (4.7 X age in years)

Note: 1 inch = 2.54 cm. 1 kilogram = 2.2 lbs.

Example:
You are female
You are 30 yrs old
You are 5' 6 " tall (167.6 cm)
You weigh 120 lbs. (54.5 kilos)
Your BMR = 655 + 523 + 302 - 141 = 1339 calories/day

Now that you know your BMR, you can calculate your maintenance level, (also known as total daily energy expenditure or TDEE), by multiplying your BMR by your activity multiplier from the chart below:

Activity Multiplier:
Sedentary = BMR X 1.2 (little or no exercise, desk job)
Lightly active = BMR X 1.375 (light exercise/sports 1-3 days/wk)
Mod. active = BMR X 1.55 (moderate exercise/sports 3-5 days/wk)
Very active = BMR X 1.725 (hard exercise/sports 6-7 days/wk)
Extr. active = BMR X 1.9 (hard daily exercise/sports & physical job
Or 2X day training, i.e marathon, competition etc.)

Example:
Your BMR is 1339 calories per day
Your activity level is moderately active (work out 3-4 times per week)
Your activity factor is 1.55
Your TDEE = 1.55 X 1339 = 2075 calories/day

4. Katch-McArdle formula

Use this formula for a very accurate estimate of your maintenance level if you know your body fat percentage and lean body mass. For fat loss, create a 20-30% deficit below maintenance.

BMR (men and women) = 370 + (21.6 X lean mass in kg)

Example:
You are female
You weigh 120 lbs. (54.5 kilos)
Your body fat percentage is 20% (24 lbs. fat, 96 lbs. lean)
Your lean mass is 96 lbs. (43.6 kilos)
Your BMR = 370 + (21.6 X 43.6) = 1312 calories
To determine TDEE from BMR, you simply multiply BMR by the activity multiplier:

Your BMR is 1312
Your activity level is moderately active (working out 3-4 times per week)
Your activity factor is 1.55
Your TDEE = 1.55 X 1312 = 2033 calories per day

Depending on your personality, you can either crunch numbers or you can take a "ballpark figure" or "portion-estimating" type of approach. Either way, the goal is the same: You have to be in a calorie deficit to burn fat. I hope you found the flexiblity offered from these different formulas helpful.

Your friend and coach,

Tom Venuto, author of
The Body Fat Solution

Don't have The Body Fat Solution yet? You can get the book in hardcover from Amazon.com, Borders, Barnes & Noble or your favorite local independent bookstore. It's also available on Audio CD and MP3 from audible, iamplify and itunes:

Click Here To Return To The Home Page