@Everyone: thanks again.
@leaner:
To establish your caloric deficit, you'll need to establish some benchmark numbers that are custom to you. To clarify, these are:
ML = Maintenance Level
RMR = Resting Metabolic Rate (same as BMR)
LAF = Lifestyle & Activity Factor
Your maintenance level represents the number of calories (energy) your body needs every day, accounting for all the activities you perform, and at your ML, you would not gain or lose weight. Of course, this is an average number, since our energy needs fluctuate from day to day. However, it represents your energy output for an average day, given your routine. Your ML is also referred to as your "Total Daily Energy Expenditure" (TDEE) in some texts. Here is the formula for figuring your ML/TDEE:
ML = RMR x LAF
HOW TO FIGURE YOUR RMR
To figure your RMR, you can either have it measured by getting yourself tested at a facility where RMR testing is offerred, or you can calculated it based on some well known formulas. To have it measured, they will have you sit comfortably in a chair for 20 minutes while you breathe into a tube, and your nose is pinched. If you don't have access to this, the calculated method works just fine. (I've actually done both, and in my experience, the numbers are very close. So just use the calculated method to get started.) When calculating your RMR, it's best to use a calculator that takes into account your current weight, height, age and gender (this is a good one ---> ) For example, when I did mine at my starting weight of 225 lbs, height of 5'5", male, age 38, my RMR was calculated at 1,859 kcal per day. (I rounded down to 1800 kcal per day just to keep the numbers simple.) Your RMR, however, only represents the number of calories/energy that it takes to keep your body alive (heart beating, organs functioning, etc.) and does not account for any physical activity at all. Your RMR is the calories your body burns just by you laying there, not moving. So your RMR is just the starting point. Next you'll need to figure your LAF.
HOW TO FIGURE YOUR LAF
The various LAF are provided by the Harris Benedict Formula, to cover your daily activity and your workout routine.
1. If you are sedentary (little or no exercise): LAF = 1.2
2. If you are lightly active (light exercise/sports 1-3 days/week): LAF = 1.375
3. If you are moderatetely active (moderate exercise/sports 3-5 days/week): LAF = 1.55
4. If you are very active (hard exercise/sports 6-7 days a week): LAF = 1.725
5. If you are extra active (very hard exercise/sports & physical job or 2x training): LAF = 1.9
In my example, I have an office job (sedentary) and my workout regimen is 3x per week. In my case (and for most people), item number 3 from above is the one that fits. So the LAF is 1.55
So, at this point, we have figured the RMR (1,800 kcal/day) and the LAF (1.55)
ML = RMR x LAF
ML = 1800 x 1.55 = 2,790 kcal/day
Now I know that my "guestimated" Maintenance Level was roughly 2,800 kcal/day. That ML number is never perfect, but it's a starting number from which you back off your calories to create that deficit.
The deficit that you choose will be based on:
1. Your Goals
2. Your Current Weight
Your Goals - here is what I mean by this. One (1) pound of fat is approx. 3,500 calories. You would need to create a deficit of 3,500 calories for every pound of fat you want to remove. If your daily caloric deficit is 500 calories, then over the course of seven days this would equal 3,500 calories for 1 lb per week. Increase the deficit to 1,000 calories per day, and your fat loss is 2 lbs per week. Before I started my personal program, I had coincidentally been at my Doctor's for a routine yearly physical and I asked him what the safe rate of weight loss per week was. He told me that they recommend a safe rate of 2.0 lbs per week. So personally, I went with 2 lbs per week as my goal.
Daily calorie intake (DCI) to create a caloric deficit:
DCI = ML - 1000
DCI = 2800 - 1000 = 1,800 calories per day
So in my case, my average daily intake number was 1,800 calories.
Before deciding on your daily caloric deficit, please read below.
WARNING - THIS IS IMPORTANT - PLEASE READ
Okay, so no one ever told me this, but it's something I learned along the way through personal experience. Let me explain this just by using real-life numbers. The numbers below show my ML numbers:
ML = RMR x LAF
ML = 1800 x 1.55 = 2,800 kcal/day @ 225 lbs (when I started)
ML = 1500 x 1.55 = 2,300 kcal/day @ 155 lbs (my current weight)
Here's what I want you to notice: everyone's Maintenance Level changes as you drop weight. It's not like you have to figure it every week. You don't. But notice that in the beginning, I could easily achieve that 1,000 cal/day deficit, because my calorie intake was 1,800 calories. If I tried to create that same 1000 calorie deficit today, that would put my daily calorie intake at just 1,300 calories! How do I know that's too low (for prolonged periods)?
Because it's below my RMR.
IMO... staying below your RMR for an "extended" period of time is unhealthy and counter-productive. Even the major health and fitness organizations recommend that minimum calorie levels are 1200 for women and 1500 for men. The bottom line is that the heavier you are (excess fat, not muscle) the easier and faster you will lose weight just by the sheer fact that your body is carrying around all those extra pounds, which makes your ML higher. My advice?
Don't go below your RMR.
Keep in mind that your ML is an estimated number. Once you establish a daily intake for fat loss, try it on for size for a couple of weeks. If you don't drop enough fat, reduce your calorie intake by 10% and make sure your workouts stay intense. Also, make darn sure you are actually accurately tracking your caloric intake. I jotted everything down and added it up at the end of every day to see where I was. Of course, I didn't *have* to do it this way, but I didn't want to take 14 months to accomplish something that I could safely accomplish in 7 months. So I chose to track calories to make sure I was hitting my numbers. And I made sure to always keep my workout routine in place. (Remember that your ML is based on your activity level. If you don't work out, you won't be achieving the deficit you're targeting.)