Hello friends. As promised, I’m here to report my mid-camp results. Now that I have results for the first 4 weeks of Biggest Loser Camp I will begin tracking my activities including food intake and exercise. We will be able to track my progress for the next 4 weeks in order to determine if simply accounting for food and activity will improve results. This is in response to my previous post wherein I suggested an experiment to support what our trainer, Jennifer Cottam, has instructed us to do from the beginning which is to track our diet and exercise.
I’ll give you my beginning measurements and then compare those to my Week 4 mid-camp measurements courtesy of Tanita Body Composition Analyzer.
Week 1 Week 4 Progress
Weight 162.4lb 158.6lbs -3.8lbs
BMI 26.2 25.6 -0.6
FAT% 21.1% 19.6% -1.5%
Impedance 474 Ohms 466 Ohms -8 Ohms
Fat Mass 34.2lbs 31.0lbs -3.2lbs
Fat Free Mass 128.2lbs 127.6lbs -0.6lbs
Total Body Water 93.8lbs 93.4lbs -0.4lbs
What does it all mean? Let’s start at the top and work down.
First of all let’s discuss weight and BMI. The scale shows that I lost 3.8lbs over the 4 week period. Using the formula, weight (kg)/height (m)^2, we arrive at 25.6. If you don’t want to convert to metric units from English units you can use the following formula: weight (lb)/(height (in) x height (in)) x 703 = BMI. According to Centers for Disease Control and Prevention BMI is a fairly reliable indicator of body fatness for most people. It is not a perfect method but can be considered and easy-to-perform alternative of screening compared to underwater weighing and x-ray absorptiometry. Normal BMI range for adults is 18.5 to 24.9. Anything above 30 BMI is considered obese and will lead to health problems.
Next we see Fat% reduction by 1.5%. This is not a calculation of fat mass lost but rather the percentage of total body weight that is fat. We’ll discuss fat mass and fat-free mass later on.
Impedance is probably the number that gets overlooked the most because it’s not very intuitive. It seems like something that an electrical engineer should know and not really something a nutritionist should worry about. I like this topic, however, because it makes sense to me. Long ago as an undergrad I declared electrical engineering as my major. This was two years before discovering a passion for biology and emergency medicine. The great thing about electricity and biology is that they intertwine.
All living organisms require energy to survive. The beauty of electricity or energy is the fact that it cannot be created or destroyed, only changed from one form to another. That’s explained in the First Law of Thermodynamics. According to the Second Law of Thermodynamics, once the potential energy locked in carbohydrates is converted into kinetic energy used for movement by an organism, the organism will get no more until energy is input again. In the process of using energy to move about, some will be lost as heat-a process referred to as entropy, which is a measure of disorder. Because the cells in a biological organism are not disordered they have low entropy. The flow of energy maintains order and life.
Simply stated, muscles work on electrical impulses from nerves. They move by transferring ions across barriers much like a battery. Muscles are inherently conductive. In contrast, skin and adipose are inherently resistant to electricity as their primary functions include protection and insulation. Impedance refers to the body’s inherent nature to resist electrical current. The correlation between impedance and fat mass can be drawn as a relationship between the amount of fat (natural insulator) in your body compared to the amount of muscle (natural conductor) in your body.
That’s probably more than you cared to know about impedance, but it’s important to know that it has meaning and could be a useful tool when combined with all the other measurements from the body composition analyzer.
Fat mass and Fat free mass should add up to equal your body’s total weight. These measurements separate the weight of your fat and the aggregate weight of everything else including muscle, bone, water, and your internal organs. Your organs comprise about 10-20% of your total weight. Having eviscerated thousands of organs in my career I can verify that the total weight of organs including intestines in a healthy adult can weigh anywhere from 15 to 20lbs. The weight of your skeleton can be estimated the same way. Your bones weigh about 15% of your total body weight.
Finally, Total body water is exactly what is implied by its title. This is the weight of all the water in your body. This big number shouldn’t be surprising given the fact that we are composed of 50-70% water.
Now to the fun part. Let’s review my stats and see if everything measures up.
My total weight at mid-camp was 158.6lbs. My fat mass and fat-free mass were 31lbs and 127.6lbs respectively. They equal 158.6lb. So far so good. Now, when I divide my fat mass by my total weight I get 0.19546. That indeed matches the Fat % number, 19.6%, provided by Tanita. Compared to my Week 1 weigh-in numbers there was a reduction in fat by 3.2lbs or 1.5% overall. These numbers suggest a reduction in Impedance and in fact we do see a reduction in resistance to an electrical current by 8 Ohms. This reduction in Impedance should correlate to an increase in muscle mass.
If I estimate the weight of my organs at 15lbs and my bones at 20lbs, then I can approximate my skeletal muscle mass at around 61.6lbs. This number isn’t perfect, however, because we have to consider my total body water weight. Unfortunately, we are limited by using only one method of measuring body composition. We can’t accurately account for water weight because water is essentially in every cell of our bodies, but I hope this was fun exercise in interpreting results from the Tanita Body Composition Analyzer.