Weekly Weigh In and Number Crunching 101

This morning's scale reading: 153.8
Official weight, as dictated by the trend line: 156.2
Pounds lost this week: 1.3
Total pounds lost: 2.8

I've been charting my calorie intake since March 11th but I couldn't chart my weight until March 19th when I finally bought a scale.  My total loss represents a bit over 3 weeks worth of work even though I've actually been at this for a month.

In addition to trending my weight in order to get a more accurate understanding of my loss, I've started keeping track of my 5 day calorie intake average in addition to my daily calorie numbers.  Just as one day's scale reading doesn't mean a whole lot in the grand scheme of things, 1 day's worth of calories isn't going to tell me much about whether I should be gaining or losing or adjusting what I'm eating.  My handy-dandy google doc now has another chart that looks like this:

I remain unimpressed with Google's spreadsheet functionality.  The blue line represents my day to day intake, and the red line is my average over the last 5 days.  This is useful to me because I need to be maintaining a certain average over time.  When I started this diet, I picked an arbitrary goal of 1500 - 1600 calories per day.  Obviously, I've got work to do.  By looking at these averages, I can get a better picture of what my weight loss is and why.  For example, last week I was losing weight at the rate of .2 lb per day, whereas the week before, I was only losing at half that rate.  Looking at the averages, we can see why.  My averages for the first week hovered around 1800 calories, whereas my averages for the second week were closer to 1600. 

This tells me that if I want to lose a pound a week, I need to average between 1600 and 1700 calories per day.  Why is this useful?  My 1500 cal/day goal was a number I plucked out of the air.  I was fairly sure that if I ate 1500 calories a day I'd lose weight, but I didn't know how much.  I didn't know what kind of a deficit that would be.  Now, based on all this data I've gathered, I know that a 1500 calorie diet would probably lead to a loss rate of a bit over .2 lbs per day.  .2 lbs = 1/5lb = 700 calorie deficit.  Since I know that 1600 calories per day leads to the .2lb/day loss, I know that on average, I burn about 1600 + 700 = 2300 calories per day. 

Let it be known that this 2300 number includes probably 200 - 300 calories of exercise daily.