I've received quite a bit of positive feedback regarding my recent series of posts on resveratrol dosage. So since you all enjoyed the multi-part posting I have decided to try it again.
What is calorie restriction? If you search the web for an answer to this question you will most likely find the following answers:
Calorie restriction (CR) is...
Starving yourself.
Eating less calories then normal.
Starving yourself.
Eating less calories then your Basal Metabolic Rate (BMR) suggests.
Starving yourself.
A lifestyle of less caloric intake based on your own personal body makeup.
So I am trying to point something out with the list above. A caloric restrictive diet is NOT starving yourself. It is however a diet in which you take a lot of time to setup and live out. You need to know certain things about yourself prior to determining what level of CR is right for you. Lets start with Basal Metabolic Rate (BMR).
What is your Basal Metabolic Rate (BMR)? BMR is a measurement of the amount of energy your body uses while at complete rest. This means no movement and an inactive digestive system which is why you need to fast for approximately 12 hours prior to testing. BMR is most commonly quoted as the amount of calories per day your body uses to maintain normal body functions.
How do I determine my BMR? The most popular method is by using the Mifflin St. Jeor equation. Here is the formula:
Men 9.99*w + 6.25*h - 4.92*age + 5
Women 9.99*w + 6.25*h - 4.92*age - 161
w = weight in kg, h = height in cm
Multiply the number you get above by an activity factor:
1.200 = sedentary (little or no exercise)
1.375 = lightly active (light exercise/sports 1-3 days/week)
1.550 = moderately active (moderate exercise/sports 3-5 days/week)
1.725 = very active (hard exercise/sports 6-7 days a week)
1.900 = extra active (very hard exercise/sports and physical job)
Conversions & Examples:
1 pound = 0.45359237 kilograms (example: 160lbs = 72.58kg)
1 inch = 2.54 centimeters (example: 5'8" = 68" = 172.72cm)
So lets go through an example with the numbers listed above:
Moderately active 32 year old male:
9.99*72.58 = 725.07
6.25*172.72 = 1079.50
4.92*32 = 157.44
725.07 + 1079.50 - 157.44 + 5 = 1652.13
Add in your "activity factor" and you get:
1652.13 * 1.55 = 2568.55kcal
Remember as with all calculations this is just an estimate. Please keep in mind there are many variables that can change your BMR.
The most effective way to measure your BMR is to use an "Indirect Calorimeter" which many nutritionists and physicians have access to. If you can have this done then by all means get the results from this machine. It is much more effective in measuring accurately and will give you a great baseline from which to work from.
Why does BMR matter so much? It is the basis of which we can determine how many calories our bodies need to "get by" on a daily basis without damaging our organs. With this measurement we are able to determine where to start with a calorie restricted diet. Deciding how many calories to cut your diet by is crucial and should be taken slowly. Never make drastic immediate changes to your diet. Take it slow.
Here is a brief look at upcoming posts in this 3 part series:
Part 2: How does trans-resveratrol relate to a Calorie Restricted Diet? (SiRT1)
Part 3: Is Calorie Restriction something I should do in conjunction with resveratrol?
As for explaining the mathematical portions of the equation any better I am not sure I am capable. However, I am working on creating a small program where you can enter some brief information about yourself (height, weight, age, and activity level) and the calculation will be done for you. It will take me some time to get together but I'll do my best to get it out over the next 2 weeks.
Many BMR calculations don't take into consideration your activity level. Now I don't have any scientific information to back-up what I am about to say and it could be completely worng, but I believe a 200lb, 30% body fat, individual would have different BMR results then the same 200lb person with only 10% body fat and an active lifestyle. I am going to look into this hypothesis to see if there are any studies out there to support it. I'll post the info if I find it.
Posted by: Admin | July 18, 2008 at 09:05 AM