Knowing your Basal Metabolic Rate: A Great Strategy to Lose Weight !

Have you ever wondered why some people are thin and others are overweight even though they seem to eat about the same amount of food ?

There could be many explanations for that behavior. Researchers have looked at many different options but we want to explore only one of them:

Your Basal Metabolic Rate = BMR

Fluctuations in our weigth are a result of our energy intake and our energy expenditure. The relationship between what we eat versus what we do is what we known as the Energy Balance Equation.

Energy Balance : Energy Intake = Energy Expenditure

To lose body weight, we have to consume more calories than we expend. This is known as a negative energy balance. To gain weight we have to consume more calories than we expend. This is known as a positive energy balance.

Energy Expenditure Is More Than Just
Physical Activity

Energy expenditure is the energy that our body expends to maintain it's basic functions such as respiration, circulation, synthesis of new cells, secretion of hormones and nervous system activity. This is what we know as Basal Metabolic Rate (BMR). About 60-70 percent of our energy/calories output every day, is a result of our BMR. That means that 60-70% of our calories are used only to maintain our body basic activities. That does not include our daily physical activities. By knowing our BMR we know the calories that our body is going to need to perform it's daily functions. The other 20-35 percent of calories are needed for our physical activities.

How do we estimate our BMR?

Convert your current body weight in pounds to kilograms. Divide pounds by 2.2
Ex. 175lb/2.2=79.5kg

Males can assume that their kilograms are almost equivalent to the kilocalories they expend per hour. That is 79.5 kcal/hour. Therefore, the BMR for a 24 hr. day is 76.5 X 24 = 1,908 calories needed for body daily functions.

Females your BMR is considered 90% of the BMR of males. If you are a women, convert your current body weight to kilograms, dividing pounds by 2.2 as shown above, then multiply your body in pounds by 0.9. Ex. 175lb/2.2 = 1,908 x 0.9 = 1,717 BMR for women.

Now that we know how to estimate our BMR,
How do we estimate the total calories that we need per/day ?

As we know already BMR account for nearly 60-70% of the energy/calories that we need to stay alive every day. How do you know how many calories do you need for your daily physical activities ? To estimate the calories that we need every day we need to know our level of activity. That is what we know as Physical Activity Level or PAL. To determine how many additional calories we need, we have to multiply our BMR by our activity level as shown below.

Acitivity Factors Based on Routine or Lifestyle

Physical Activity Level = PAL
Very lightly active
lifestyle 1.2 -1.4

Sedentary active
lifestyle 1.4 -1.7

Moderately active
lifestyle 1.7 -2.0

Vigorously active
lifestyle 2.0 -2.4

Therefore, if you have a BMR of 1,717 and you have a moderately active lifestyle you need:

BMR = 1,717 x 1.7 = 2,918 calories

But I am overweight, How can I lose weight?



Pound of fat:
represents aproximately 3,500 calories. To burn this amount of energy/calories we need to reduce our intake and increase the level of activity. We need to create a negative energy balance. As we mentioned before that occurs when you expend more calories than you consume.

To lose 1 or 2 pounds per week, a daily deficit of :

500/1,000 calories is required

Following our previous example a total of 2,918 daily calories were needed to mantain a moderately active level style. If we decide to lose 2 pounds per week we need to substract to that amount, 2,918 a total of 1,000 calories every day. That will result in a diet of 1,900 daily calories. We should always have in mind that a daily intake below 1,200 calories is not recommended. It will be difficult to get all the daily nutrients that we need with such a restricted diet.

Achieving a healthy weight is important but an aggresive weight loss regime can result in loss of lean body mass. Loss of lean body mass can reduces energy needs. In addition the heart is a muscle, and rapid weight loss can weaken it. That's why your weight maintenance strategies should be designed to promote fitness.

Think fitness first and then body weight!




Tips to lose weight

1. Distribute your daily calories.
2. Eat small portions and snacks between meals.
3. Increase your fruit and vegetable
consumption.
4. Include whole grains, lean protein and low
amount of fat. That is a good combination for
weight loss.
5. Move to lose !!


BMR varies widely among people. Factors that influence your BMR:

1. Lean Body Mass - is more metabolically active than fat tissue, therefore more calories are needed to maintain it.

2. Gender - women have less lean body mass than men. This result in women having a lower BMR (up to 10% lower).

3. Age - for adults BMR declines about 1-2 percent per decade after the early adult years

4. Body size - taller individuals will have a higher BMA due to increase surface area compared with shorter individuals.

5. Stress - hormones release during emotional stress increase BMR.

6. Starvation - and fasting for more than 48 hours lower BMR.