Body fat scales function by sending out a low electrical current throughout your body and gauging body fat based on bioelectrical impedance. Impedance in laymen's terms is simply a measurement of the resistance to current. Since muscle tissue is comprised of mostly water, there is less impedance when a current passes through muscle compared to fat since water is conductive. Thus, the higher the impedance the more body fat you have. The scales utilize formulas (based on gender, age, ethnicity, height, and weight) to calculate body fat percentage from the impedance measurement.
The problem with body fat scales is that many factors exist (e.g., how hydrated you are, when you last ate and exercised, the quality of the scale itself, etc.) which can cause inaccurate measurements in body fat. For instance, the scales may underestimate those with higher body fat and overestimate those who are leaner. Also, the body fat scales tend to be inaccurate in elderly people, athletes, children, and people with osteoporosis.
BOTTOM LINE: If you do use a body fat scale, it's recommended that you utilize the body fat scale as a means to track body fat changes over time (i.e., on a monthly basis) rather than as an absolute value. To obtain more accurate relative changes in your body fat, it's recommended you step on the scale upon wake-up with no clothes on before eating any food. Remember: focus on changes over time rather than any single measurement.
Brian Danley, CFT
"Motivation is what gets you started. Habit is what keeps you going."
Brian Danley, CFT "Motivation is what gets you started. Habit is what keeps you going." 408-688-1586 (cell) briandanleyfitness.com https://www.linkedin.com/in/briandanleyfitness https://www.facebook.com/BrianDanleyFitness
Subscribe to get the latest blog content:
I'm a personal trainer who loves to help others fulfill their health and fitness goals. I consider myself a bodybuilder in that I live the lifestyle of eating healthy food, working out regularly, and sculpting my body.