Metabolism slowing down

A few months ago I bought myself some Tanita scales. These are quite high tech and are a domestic version of the more expensive scales that they use in hopsitals. It tells you your weight (of course), total body water, muscle mass, visceral mass, metabolic age and rate, and total body fat. When I first started using it, my basal metabolic rate (the amount of calories I need to consume to maintain my current weight and just keep my body going - without any exercise or activity) was 1960. Over the past few months I have watched it go down and down - and this morning it was at its lowest ever - 1572! This is quite normal - your body needs less calories (it puts out less energy) doing basic fuctions when you weigh less. This means that if I laid down all day and did nothing but breathe and circulate my blood, I would need to consume that many calories to maintain weight. Of course, I don't usually lay down all day - more calories are needed to cover acivity, walking, working etc. But also I don't want to maintain my current weight of course - I want to lose weight. To lose weight, the total calories I consume needs to be less than my basal metabolic rate (BMR) plus calories burned through activity. So, every time my BMR goes down, one of two things happens. Either, my weight loss slows down, or, I can maintain my rate of weight loss by consuming less or exercising more. In other words, this is mathematical proof, if ever it were needed, that weight loss gets harder the more you lose!!!