Sunday, August 30, 2009

Calculating my Daily Recommended Calorie Needs

It is of importance that we calculate the Daily Recommended Calorie Needs (DRCN) so that we know exactly how much our body needs. Weight-loss is not as simple as ensuring the loss of calories, we also need to ensure that we do not "over-lose"hence enabling the 'starvation response'.


The formula below can look menacing at one glance but it's really simply primary school mathematics, all you need a calculator or MS Excel to do the calculation for you.

In order to get the DRCN value, we need to calculate our Basal Metabolic Rate (BMR):

Harris Benedict Equation:
Formula for women:
BMR = 655 + (9.6 x wt/kg) + (1.8 x ht/cm) - (4.7 x age/yr)


Formula for men:
BMR = 66 + (13.7 x wt/kg) + (5 x ht/cm) - (6.8 x age/yr)



Using the value you've gotten, multiply it with the value assigned to your activity level to get your DRCN.

Example:

I am a woman, weighing 54 kg, 165 cm tall, 28 years old and lightly active.

Using MS Excel, I'll key in "=655+(9.6*54)+(1.8*165)-(4.7*28)" to get my BMR as 1338.8 cal.

My DRCN is therefore = 1338.8 x 1.375 = 1840.85 cal

To give you an idea of how much you can eat a day, a plate of Char Kway Teow (something like fried noodles for the foreign friends) is about 700 cal and a Mac Fish Burger Meal (Upsized) is about 850 cal... so... have you been over-eating??

In order not to reach the "starvation response", we should not cut more than 20% from our DRCN. Which means, in order to lose weight, I should try to consume only (1841x0.8=)
1472.8 cal per day. Note that you calorie intake should increase with each increase in activity level, and also note that this 20% range will take you at least 3 mths to lose a mere 4kg (estimate, varies from person to person due to difference in age, weight and height). If you really can't wait, the lowest level of DRCN a women need is 1200 cal, but you'll have to take care of the health consequences that will follow (e.g. sharp increase in weight the moment this low-cal diet is stopped, muscles degenerate, low metabolism, lethargic, dizzy-spells etc.)

1 comment:

  1. Coming up: "How to lose weight" for the next blog.
    Stay Tuned!

    ReplyDelete

 
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