You finally got a plan together to start losing weight. As you get started, and the first few pounds start coming off, you might start wondering how much fat you are actually losing. It turns out that seeing the number change on the bathroom scale may have less to do with healthy weight loss than you think.
DR. CHRISTOPHER MCGOWAN
Dr. Christopher McGowan, MD, a leader in endobariatrics, specializes in non-surgical obesity treatments and is triple-board-certified in Internal Medicine, Gastroenterology, and Obesity Medicine. Renowned for pioneering endoscopic sleeve gastroplasty (ESG) with over 2,000 procedures, his global influence and research contributions define him as a top expert.
The kind of weight you lose is almost as important as how much weight you drop. But how are you supposed to find out whether you are losing fat or not? That is the question body composition measurements try to answer.
What is Body Composition?
Body composition or body fat percentage measurements are ways to look at the ratio of fat to lean muscle mass your body is made of. This measurement, even more than the commonly used body mass index or raw numbers on the scale, can help you understand how much weight you need to lose and how great your risk might be for heart disease, diabetes, and conditions related to excess visceral fat and obesity.
Everyone’s body composition is different, and yours can change quite a bit throughout your life depending on your diet and level of exercise. Body fat measurements are more accurate predictors of the health risks you might be up against than simply going off your raw weight or looking at your BMI.
How is Body Fat Measured?
There are several ways to measure your body composition. These include everything from relatively cheap bathroom scales you can buy for your home to expensive evaluations requiring dedicated equipment and trained professionals to perform. The methods used vary depending on the type of test, but fat can be measured by:
- electrical impedance
- air displacement
- water displacement
- caliper measurements
- waist circumference
As in many areas of life, you get what you pay for in measuring body fat. The simplest, cheapest, though generally less accurate way of measuring your percentage of body mass, is by using body fat scales. These upgraded bathroom scales use bioelectrical impedance analysis (BIA) to measure the amount of body fat relative to your overall weight. These scales are notoriously inaccurate, though, and should only be used as a general guide for checking your progress in weight loss.
A relatively new technology in the area of body fat measurement is the DEXA scan. Dual-energy X-ray absorptiometry is a process similar to the X-rays doctors have long used to check for broken bones. DEXA scans look at more than just your bones, though, as they take measurements of your overall body fat, bone mass, and lean muscle mass to get very accurate body fat readings.
Density and displacement are the concepts behind two of the most common ways to evaluate body composition. Hydrodensitometry testing involves being submerged in water and measuring the amount of fluid your body displaces. The math behind these tests is well established, so readings tend to be quite accurate.
For people who are uncomfortable around water, options like the Bod Pod that work by using air displacement can perform the same basic measurement as the water displacement test. You do need to keep control of your breath, as that can cause fluctuations in readings, but this is a far more convenient way to weigh in than jumping in a pool.
One of the last methods to check your overall amount of body fat is with skinfold calipers. This measurement is one that is highly dependent on the skill of the technician performing the test. If the person performing the test is not experienced, it is not uncommon to have a caliper test to underreport the amount of fat.
Are Scales that Measure Body Fat Accurate?
If you think it sounds too good to be true that a simple bathroom scale could do the same job as expensive, dedicated testing equipment does, you would be right. Bathroom scales that measure body composition through bioelectrical impedance analysis are not extremely accurate.
The weakness of this form of testing is that changes in your hydration can have a profound impact on the accuracy of the reading. To be able to get good readings on your fat loss over time, you will need to be very consistent about the time of day, amount of fluid you have consumed and other factors to ensure accuracy and consistency from one measurement to another.
How Accurate are Smart Scales?
Technology is always improving, and smart scales are no exception. The analyzer living on your bathroom floor is limited, though, in that it’s only measurement aside from raw weight is made by passing a weak electrical current through your body and measuring the impedance on that current. As noted above, the challenge here is that changes in your hydration level, fluid and food intake, and even your menstrual cycle, can affect your ability to get accurate readings out of these scales. Under good conditions, smart scales could still be as much as 5% off in either direction.
Losing Weight the Healthy Way
One of the most important things to remember about weight loss is that the final number on the scale is not the only measure, or even the best metric, for tracking your progress. Though many people focus on that big number on the scale, the real picture of how healthy you are is more nuanced.
Maintaining or increasing your level of lean muscle tissue, especially early on in your weight loss journey, is going to be key. Since muscle weighs more than fat, this could mean that your weight might stay the same, or even go up a little as you start to add on muscle mass. This shouldn’t be a cause for alarm if you are keeping to diet and exercise goals you established with a dietitian or nutritionist.
It can feel like a bit of a challenge to get your head around the specifics of successful, lasting weight loss. At True You, we help people sort through this maze of alternatives to find the option that is right for them. We cover the spectrum, working with patients who are just beginning to make healthy decisions after years of living with excess body fat, to those who have already undergone a bariatric surgery and need to get back on track to keep the pounds off.
There are even some people where the measuring, weighing, dieting, and exercise are not proving to be enough. If you are in this category, and have been for years, you may be a candidate for a weight loss procedure to help get your weight under control. If this sounds like you, request an appointment today to learn more about the procedures we perform and whether they could help you achieve the freedom from excess body weight you have been looking for.
