I have an older model of the bodybugg and I find it very useful in determining my calorie burn for the day. It takes several factors into consideration (do a google search) in addition to gender, height, weight, etc. I use it as a gauge to how many calories I burn on sedentary vs active days so I can know how many calories I can eat to maintain/lose. I wear it for 2-3 days straight and print out the graphs is generates and find my average burn for x activity. Then I take it off and let the scale tell me my progress. I'll sign up again in Sept when I restart to get new baseline measurements. I found it useful for me because of all the conflicting info on websites on how many calories I need to maintain/lose and burn in such and such activity. I KNOW I burn 12 calories a minute jogging, for example and I KNOW I burn 2300 calories a day without a work out and upwards of 2800 when I do. I have been maintaining for over a month now with a 1-2 pound flucuation based on this info, so it is working for me
YMMV