How Many Calories Should I Eat to Lose Weight?

Many people wonder how many calories they should eat to lose weight. This article will answer this question. But, before you can know how much calories you should eat to lose weight, you need to know your maintenance level calories.

"Maintenance level calories" can be called as, "daily caloric needs" or "total daily energy expenditure" or in short as TDEE.

TDEE (or maintenance level) is the level that your deposit calories are exactly equal to your withdrawal calories.

TDEE is the total calories our body burns in 24 hours (including basal metabolic rate and all activities.)

For example, you have 2500 calories per day as your maintenance level (TDEE).

• If you consume less calories than your TDEE (for example 2400), you will lose weight.

• If you consume more calories than your TDEE (for example 2600), you will gain weight.

• If you consume same calories as your TDEE (for example 2500), you will maintain the same weight.

In short, to lose your weight, first you need to know your TDEE (maintenance level) and then make sure that you consume less calories than your TDEE.

There are 4 ways to calculate your maintenance level calories. Some are easy to calculate. Some are more accurate. We will discuss those 4 methods on how to calculate your TDEE (or maintenance level calories).

1. The Average Method - This one is easy, but less accurate.

2. The Quick Method (based on bodyweight) - This one is also easy, but less accurate, too.

3. The Harris-Benedict Formula - This one is moderately accurate.

4. The Katch Mcardle Formula - This is the most accurate method.

How to Calculate Your Maintenance Level Calories

1. The Average Method

According to exercise physiologists William McArdle and Frank Katch, below is a table of average TDEE of people in United States.

According to exercise physiologists William McArdle and Frank Katch, below is a table of average TDEE of people in United States.

This is average calories range only. It is not really accurate. But it may give you an idea of your TDEE. (Note: TDEE for everybody will vary from person to person.)

2. The Quick Method

This method will use your total bodyweight to calculate your TDEE.

This method is very easy to estimate your TDEC, but no really accurate. It might over-estimate or under-estimate for some people.

3. The Harris-Benedict Formula

The formula will use basal metabolic rate (BMR) and activity factor to calculate the TDEE (maintenance level calories).

There is different formula for men and women.

This method is more accurate than the two methods above, but not as accurate as Katch Mcardle Formula.

How This Formula Calculate:

• First, you calculate the BMR.

• Then, multiply BMR with activity factor.

• Finally, you will get the TDEE.

The Formula:

For men, the formula for calculating BMR is:

BMR = 66 + (13.7 x Weight in Kilograms) + (5 x Height in Centimeters) - (6.8 x Age in Years)

For women, the formula for calculating BMR is:

BMR = 65.5 + (9.6 x Weight in Kilograms) + (1.8 x Height in Centimeters) - (4.7 x Age in Years)

And

TDEE = BMR x Activity Factor

(Note: 1 inch = 2.54 centimeters, 1 kilogram = 2.2 lbs.)

The Table of Activity Factor and TDEE:

Example 1 (Male):

You are male, weight 75 kg, height 170 cm, 30 years old, and lightly active (or 1.375).

Your BMR = 66 + (13.7 x Weight in Kilograms) + (5 x Height in Centimeters) - (6.8 x Age in Years)

= 66 + (13.7 x 75) + (5 x 170) - (6.8 x 30) = 1739.5 calories

Then, your TDEE = BMR x Activity Factor

= 1739.5 x 1.375 = 2391.8125 or round up as 2392 calories

Example 2 (Female):

You are female, weight 65 kg, height 165 cm, 30 years old, and lightly active (or 1.375).

Your BMR = 65.5 + (9.6 x Weight in Kilograms) + (1.8 x Height in Centimeters) - (4.7 x Age in Years)

= 65.5 + (9.6 x 65) + (1.8 x 165) - (4.7 x 30) = 845.5 calories

Then, your TDEE = BMR x Activity Factor

= 845.5 x 1.375 = 1,162.5625 or round up as 1163 calories

4. The Katch Mcardle formula (based on LBM)

The formula will use lean body mass (LBM), basal metabolic rate (BMR) and activity factor to calculate the TDEE (maintenance level calories).

The formula is for both men and women.

This method is the most accurate among all methods.

How This Formula Calculate:

• First, you calculate lean body mass (LBM)

• Next, you calculate your BMR.

• Then, you multiply BMR with activity factor.

• Finally, you will get the TDEE.

The Formula:

LBM = (Weight in Kilograms) - (Weight in Kilograms x Body Fat percentage)

BMR = 370 + (21.6 x Lean Body Mass in Kilograms)

And

TDEE = BMR x Activity Factor

Example:

You are male, weight 75 kg, body fat 15%, and lightly active (or 1.375).

(Note: You can know your body fat percentage by get a skinfold test.)

Your LBM = (Weight in Kilograms) - (Weight in Kilograms x Body Fat percentage)

= (75) - (75 x 0.15) = 63.75

Your BMR = 370 + (21.6 x Lean Body Mass in Kilograms)

= 370 + (21.6 x 63.75) = 1,747 calories

Then, your TDEE = BMR x Activity Factor

= 1747 x 1.375 = 2402.125 or round as 2402 calories

Conclusion:

First, you need to know your TDEE (or maintenance level calories) by using Harris-Benedict Formula or Katch Mcardle Formula. Then choose to do what you want:

• If you want to lose fat (weight), ensure that your total daily calories from the meal are less than your TDEE.

• If you want to maintain the same weight, ensure that your total daily calories from the meal are equal to your TDEE.

• If you want to gain weight, ensure that your total daily calories from the meal are more than your TDEE.

Back to the question, "How many calories should I eat to lose weight?" The answer is to eat less calories than your maintenance level calories.

You may still wonder how much less calories you should go for. This is another question that this article will answer.

As theory, to lose weight, you must create negative calorie balance (called "calorie deficit"). There are two ways you can create a calorie deficit.

Option 1: You increase your activities (aerobic exercise and weight training).

Option 2: You decrease calories consumed.

The best option to lose weight faster is you combine the two options above.

The most efficient approach to healthy weight loss is to increase your activity a lot and decrease calories a little.

1) General Guideline of Cutting Calories (Absolute Number Method):

The general guideline is to reduce calories by 500 to 1000 less than your calorie maintenance level.

For examples:

• A lady with a 2000 calorie maintenance level, then a 500 calorie deficit will put her at 1500 calories per day. (If calculate as percentage: 500 / 2000 = 25%)

• A man with a 2800 calorie maintenance level, then a 500 calorie deficit will put him at 2300 calories per day. (If calculate as percentage: 500 / 2800 = 17.86%)

2) Lose One Pound or Two Pounds per Week:

A 500 calorie deficit over 7 days is 3500 calories deficit in one week. There are 3500 calories in a pound of fat. This means that a 500 calorie deficit would result in a loss of one pound of body fat per week.

By the same calculation, then a 750 calorie deficit would result in a loss of one and a half pounds per week while a 1000 calorie deficit would result in a loss of two pounds per week.

But this is in theory only. In real life, the body has weight regulating mechanism, and in the long run, fat loss seldom works like this calculation.

3) The Better and Individualized Guideline of Cutting Calories (Percentage Method):

A 500 to 750 calorie deficit below the calorie maintenance level is usually huge. It might lead to the activation of starvation response. By the way, the better and preferred approach is to decrease your calories about 15 - 20% of your calorie maintenance level.

For examples:

• A lady with a 2000 calorie maintenance level, 20% will be a 400 calorie deficit, which will put her at 1600 calories per day.

• A man with a 2800 calorie maintenance level, 20% will be a 560 calorie deficit, which will put him at 2240 calorie per day.

The reason behind using the percentage is better because using number like 500, 750 or 1000 calories as deficit might put you into a danger zone.

From the above example, a 500 calorie deficit of 2000 calorie maintenance level for the lady is 25%. This might be too high for her. While a 500 calorie deficit of 2800 calorie maintenance level for the man is 17.86% is a proper one.

Ok, back to our first answer, "How many calories should I eat to lose weight?" The answer now is you should eat less than your maintenance level calories 15% to 20% (as we have discussed in the above examples).

Hope this article gives you the satisfied answer to the question, "How many calories should I eat to lose weight?"