By Roy M. Wallack, Special to The Times

If you knew how many calories you ingest and burn, you could gain better control over your weight. A recent study published in the Journal of the American Medical Assn. showed that even a simple step counter or pedometer triggers the average user to increase movement by 2,100 steps per day. The devices below can bring a new level of convenience and accuracy to calorie counting.

Irvine-based endurance cyclist and runner Roy M. Wallack is the coauthor of "Bike for Life: How to Ride to 100." Reach him at roywallack@aol.com.

Computer-savvy armband

Body Bugg: An armband sensor records your activity level for analysis on your computer; a wristwatch provides real-time readout.

Likes: It's tremendously motivating to see how your body is actually functioning. Once you've set up an Internet account, you can load data in seconds from the armband to your PC, providing a 24-hour graph of your activity. After you spend several minutes inputting the foods eaten during the day, you get a readout of calories burned and consumed.

Dislikes: Not Macintosh-compatible or waterproof. Also, logging on to the website is inconvenient. Why not provide the program on CD?

Price: $349.90. (800) 656-2739; bodybugg.com