Recent estimates from the Center for Disease Control say almost two thirds of the population of the U.S. is either overweight or obese. Multiple chronic health issues related to being overweight include diabetes, high blood pressure, heart disease, degenerative changes in back and knees, and cancer. People with weight issues often want quick solutions. Rapid weight loss claims like losing 40 pounds in four weeks ignore established medical research recommending a one-pound weight loss per week for women, and 1-2 pounds per week for men. With rapid weight loss, muscle mass (one of the most important biomarkers of aging) is also lost. Many highly advertised weight loss programs fail to offer a specific plan to maintain muscle mass while losing fat – in other words, how to maintain a healthy body composition. In studies, there is increasing focus on healthy body composition instead of just weight loss since it is well known that aging, sedentary lifestyle, weight gain, chronic disease, and poor nutrition can lead to unhealthy changes in body composition.
Body composition can be measured through a simple, non-invasive device called a bioimpedance analyzer. A mild current, which cannot be felt, is passed through electrodes attached to the foot and hand. The current passes through the different body compartments: intracellular water, extracellular water, fat mass, and free fat mass (everything other than fat). If the current passes slowly, there is more fat mass and extracellular water. If it passes through more quickly, there is more intracellular water and muscle tissue. The analyzer is also programmed to calculate the amount of stored energy in the cells and cell membranes, called phase angle and body capacitance. Not surprisingly, healthy people have more stored energy than unhealthy people. Bioimpedance correlates quite well with the DEXA scan, which is considered the gold standard for measuring fat, muscle, and bone mass, but uses radiation so it cannot be used for regular assessment of body composition.
Traditional markers of total body weight, body mass index (BMI), and waist circumference are helpful for baseline information but cannot tell whether a person is gaining or losing muscle mass, or shifting from unhealthy extracellular water to healthier intracellular water. By measuring these latter biomarkers, along with the phase angle marker, we can track nutritional and lifestyle changes, and minimize the otherwise inevitable consequences of aging and disease.
A new term called â€˜sarcopenic obesity’ is appearing in the medical literature. Simply put, it means loss of muscle mass while fat mass increases. Reduction in muscle mass can be caused by previous bouts of crash dieting, inadequate protein intake and inactivity. Sarcopenic obese people may even have a normal or low BMI measurement and look thin, but have a relatively high fat ratio – lending the term “skinny fat people”. Research from UCLA Center for Human Nutrition showing bioelectrical impedance measurements made of young women at increased risk of breast cancer demonstrated sarcopenic obesity in 38 out of 40 women. In these women, body fat is best reduced by encouraging heavy resistance exercise rather than simply restricting calories. Increasing their muscle mass will help increase their basal metabolic rates and burn more fat.
Incorporated into a comprehensive therapeutic lifestyle management program, bioimpedance analysis, performed every few weeks, can be a powerful tool to monitor body composition changes. It is also a great motivator as people see the results of the lifestyle and dietary changes they have made. With weight loss, slower is healthier, and energy usually improves quickly. Medical studies agree that maintaining muscle mass and minimizing fat mass is one of the best indicators of healthy aging.