the bit that says base metabolic rate ...means thats the amount of calories it takes for you to stay the exact same weight....so in other words increase your calories from that and you will put weight on ....and vice versa...
but like has already been said....them machines are useless ....the only real way to know your base matabollic rate is to keep a log of your calorie intake over a period of time....a good few weeks or longer with your weight not really changing