As I mentioned back in November 2011 (The Mass of Sisyphus) I don’t seem to be able to keep my weight stable at a level with which I am comfortable. Since I wrote that, I have lost around 6 kg but I seem to be stuck at about 80 kg. Now I have at last found an explanation based on physiology and physics.
The Body Weight Simulator is available is a piece of ‘java’ software from the US National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). The software runs directly from your web browser and requires various inputs (mainly initial weight, height, age and level of activity) that allows it to estimate how many food calories you require each day. Significantly this number differs from the standard numbers for adults (e.g. 2500 calories for an adult male).
One of the insights embodied in the software is that heavier people have a higher calorific requirement. So if you restrict your diet by 500 calories per day, your weight will not fall indefinitely, but stabilise at a new lower value. This is what I have observed previously, but never really understood.
For example it tells me to that get from 80 kg to 75 kg in 50 days I need to restrict my diet by around 713 calories per day (if I don’t do any extra exercise). Additionally it tells me that in order to maintain a weight of 75kg, I need to restrict my calorie intake permanently by 87 calories a day compared to what I am doing now.
It’s possible to cut and paste the predicted weight data and so I can compare theory and experiment – see below – and the numbers are sort of plausible.
So now I will sit at my computer for even longer and consider strategies which will allow me to reach – and maintain – a body weight of 75 kg. Mmmm. Or maybe I should just go for a run…