Over the past week, several people have asked me: "How did you lose so much weight so fast?"  I wanted to convince myself and wanted to be confident that the path to my goals was sustainable as the rate of my weight loss levels off.

My immediate, significant weight loss makes sense because of the immediate, significant changes made in my life.  It was easy to determine from information I had logged that a big chunk of the month's loss was in the very first week.   That result was a one-time deal and for good reason.  In my opinion, my body lost a lot of water and purged itself of toxins and waste.  In other words, I cleansed my body and got it healthy REAL FAST.  I could actually feel it as it happened, like a chemical reaction in a test tube.

Since my weight and body fat percentage changed, I decided to revisit that metabolic calculation with those new numbers.  While doing so, I also reviewed data logged daily since the first weigh-in.  I decided to ignore that one-time, first week's plunge, and start at the second week.  So, I looked at my weight taken every Saturday morning on my scale, with weekly weight losses in parentheses:

January 26 - 199.8 (used as starting point)

February 2 - 197.2 (down 2.6 pounds)

February 9 - 195.4 (down 1.8 pounds)

February 16 - 193.4 (down 2 pounds)

February 23 - 191.2 (down 2.2 pounds)

March 2 - 188 (down 3.2 pounds)

This is a loss of 11.8 pounds in 5 weeks or an average of between 2 and 2-1/2 pounds a week.  Good.  I'll take it.  But this is not so much, really.  And all of this confirms what I already knew back in January.

1,800 calories per day = "calories in" (from consistent, healthy diet)

1,778 calories per day = current Basal Metabolic Rate (re-calculated by Vitabot)

As mentioned in my earlier blog, these numbers cancel.  My weight loss is expected to come entirely from my activity level.  Two hours on a treadmill at 4.4 mph burns about 1,100 calories.  With fat weighing 3,500 calories per pound, I should expect to lose 2 pounds a week, which the numbers above confirm.  If I do other activities in addition to my workout, my body burns MORE than 1,100 calories a day.  If I eat less than 1,800 calories a day, I have that much less to burn.

THE GOOD NEWS:  Strict diet and strict workout schedule means my weight loss will not average less than 2 pounds a week.

THE BAD NEWS:  The math proves some limits here.

For example, to lose FOUR pounds a week would require a calorie deficit of 14,000 calories per week or 2,000 calories a day.  To do this would require limiting my diet to 900 calories AND keep burning a total of 2,900 calories per day (1,800 basal / 1,100 from activity).  Or I could stay with my current diet and DOUBLE my activity level.  Either method is impossible to sustain for 6 months - probably impossible to sustain for 6 DAYS.

Option 1 "Starving" provides too little energy (from food) to work out
Option 2 "Work out 4 hours a day" is not practical from a time standpoint

This proves why weight loss experts say that too much weight loss too quickly is unhealthy or unsustainable in the long run.  Two pounds a week, I just proved to myself, is do-able.