Note: I’ve created a reference page with links to the various resources I’ve used to compile my fat loss plan here.
This post is the first in a series of posts I am doing to work through a detailed plan to obtain each of my annual goals. The CEO at my last company always used to say “Plan your work then work your plan.” I’ve found through experience that this is the only way to achieve anything that requires more than a couple of weeks effort. The results are more gratifying when you achieve something you’ve had to to really push yourself to accomplish.
Losing weight by the numbers
As an engineer, when I attack a problem I typically try to break it down as scientifically as possible. I really like it when I can use simple math to prove or disprove that a plan has even the potential to be successful.
It is a fact that one pound of fat is roughly 3500 calories of energy. To lose one pound of body weight all you have to do is burn 3500 calories more than you consume . Spread over 7 days it takes a deficit of 500 calories a day on average to shed a pound of body weight:
Calories Consumed – Calories Burned = Calorie Deficit (or surplus)
While it requires a lot of discipline, it is fairly simple to total up how many calories you consume every day using a food journal and online food databases. Simply record everything you eat, when you eat it, and keep a running total to. This is the hardest part.
It’s a lot easier to figure out roughly how many calories you burn in a day by figuring out your Base Metabolic Rate (BMR) and then using a multiplier based on whether or not you worked out that day:
BMR x Activity Factor = Calories Burned
I used a free website to calculate my BMR at ~1900 calories. I use a multiplier of 1.2x on days that I work at my sedentary job and 1.7x when I have a great workout. This comes out to:
Off Day: 1900 BMR x 1.2 AF = 2,280
Workout Day: 1,900 BMR x 1.7 AF = 2,850
I know I want to run the Capitol 10K again this year on April 11th and I’d like to run that race 10 lbs lighter than I was last year (@199 lbs) which comes out to 189 lbs. Working backwards, I have to lose 14 lbs in the next 12 weeks which comes out to a 595 cal/day deficit or a little over 1 lb/wk. That will be a challenge but it is doable. The same calculator tells me that I can safely lose up to 1.9 lbs / week (even though that would require extreme discipline and will power).
So my daily food intake will have to look like this for me to win:
Off Day = 1,685 consumed – 2,280 burned = –595 deficit
Workout Day = 2,255 consumed – 2850 burned = –595 deficit
All of these calculations are based on general formulas and estimations of calories consumed so they can be subject to a margin of error. It would be reasonable to consistently be off by a few hundred calories every day. To help prevent this from happening, I use another online tool that calculates my actual weekly weight loss trend and daily deficits using scale weight (taken each morning prior to breakfast).
In 2007, I proved that all this works by losing 15 lbs in 8 weeks by running a 600+ cal/day deficit and losing 1.24lbs/week on average (See the graph below. The grey line was my actual weight each morning on a scale while the red line is a smoothed trend line. This graph was generated by The Hackers Diet Online). I was training for a 5K that December and I weighed in at 184.5 the morning of that race.
Losing the right weight
Running daily caloric deficits are not the whole story. I also need to make sure that I’m losing the right kind of weight. I’ll be following the principles laid out in the Body For Life program which uses resistance training + interval training + a balanced diet to make sure to lose fat and not lean muscle mass.
This can also be tracked by periodically measuring Body Fat using inexpensive calipers and then calculating “fat mass” by multiplying current scale weight by BF%. My current calculation is:
203.6 lbs x 22% = 45 lbs fat mass
If my diet and training routine work properly, I should see fat mass decreasing at a rate equal to or higher than scale weight decreases. If body fat shrinks slower than scale weight then I can assume that I must be dieting too hard and causing my body to break down muscle tissue for fuel. This would be counter productive to my goals and would signal that I need to re-evaluate the plan and possibly slow down my weight loss.
I’ve read that athletes can not lose fat and build muscle at the same time but that “beginners” can. In this context I think I’m still considered a beginner because my body is far from “optimal”. Periodic measurements will tell me if the plan is working regardless of what I feel should happen though. 😉
After April 11th
My 2010 goal is to weigh 180 lbs (or less) and to remain steady there. I want to lose the weight conservatively though. I’m also thinking about key dates based on a few races I know I want to enter this year (as part of my Be a Triathlete goal).
I’m currently only focused on losing 14 lbs for the Capitol 10K event in April with plans to reevaluate where I’m at after that race. Right now I think it would be prudent to hold around 190 lbs for a month or so to give my body time to adjust while training for my first Tri in May. After that I’ll have to set a new date to drop the final 10 lbs. I’m thinking about doing another Tri event in July and that would be good timing for losing another 10 lbs and finally reaching that 180 lbs goal.
So right now, my overall plan looks like this:
- January 1st – 206. Began counting calories and cutting.
- April 11th – 189. Run Capitol 10K race 10 lbs lighter than last year.
- April/May – 190. Hold weight for 1 –2 months.
- July – 180. Begin second calorie counting and cutting routine.
- July – Dec – 180. Hold 180 +- 5 lbs to achieve 2010 Goal #1