Saturday, June 15, 2013

Six-month weight trend line: Jan - June 2013

Since I started Michael Mosley's 'Fast Diet' in August 2012 I've been taking digital weight measurements most days. Today I entered this year's dataset into an Excel worksheet and plotted the scatter diagram shown below. Days since Jan 1st 2013 are on the x-axis, weight (in kg) on the y-axis.

I've added the regression line. The R-squared statistic for this data set is the square of the correlation coefficient, so the correlation between weight and elapsed-time is around 0.7. This shows a real trend.

The bouncing around of the data from the trend line reflects days of eating and days of fasting.  Food taken on board during an eating day can weigh of the order of 1.5 - 2 kilograms. This gets mostly metabolised into water, carbon dioxide and solid waste over the next day or two. Hence the jagged shape to the data based on fasting two days a week. The data tends to cluster within +/- 1 kg of the trend line.

I have a target: be at a mean weight of 68 kg = 10 st 9.6 lb and wobble by around +/- 2 pounds during a typical week. The trend line says I will get there on September 6th 2013.

My weight (kgs): Jan 1st - June 15th 2013
During a  six day holiday at day 125 I didn't weight myself for almost a week. I interpolated the data and you see a suspiciously straight line - and a certain amount of weight gain!