Bioelectrical Impedance Analysis:

One method of estimating body fat is through bioelectrical impedance (BIA). It is a painless and easily accessible procedure that is safe for most individuals. Those with a pacemaker or women who are pregnant should avoid the test.

How does it work?

The test works by passing a low level imperceivable current through the body. The current moves faster through fat-free mass, due to its higher water content, than fat mass. The resistance that the current encounters is measured and then plugged into a mathematical equation to come up with total body water, fat-free mass, and body fat.

How accurate are the results?

BIA has a 3-4% chance of error under optimal testing conditions. Thus if your result indicates 30% body fat, this could mean you have 26-34% body fat. You can expect this same level of accuracy with other practical body composition testing procedures.

What are optimal testing conditions?

The test is highly dependent on hydration level at the time of the test. For the most accurate results, it is important to be perfectly hydrated. Thus, prior to the testing, you should be informed of a hydration protocol to follow. This may include avoiding exercise for 4 hours prior to the test, avoiding a meal for 3-4 hours prior to the test (water is ok), avoiding saunas, and abstaining from alcohol for 12 hours prior to the test. Make sure to ask the clinician who performs your test about the pre-testing requirements.

Pros:

• Generally inexpensive test.
• Very quick. The test takes less than 1 minute to conduct. Yet discussing the results can take some time, depending on the questions you have and your health goals.
• It is much more accessible to the general public. Of note, bioelectrical impedance is not as valid and reliable as hydrostatic or underwater weighing.
• Operating a bioelectrical impedance machine doesn’t require formal training. This is quite different from skinfold caliper testing which requires that the skilled and competent clinician complete the test using high quality calipers and inputting the numbers into an appropriate equation.

Cons:

• Those who are pregnant or have a pacemaker should avoid BIA.
• Hydration level greatly impacts the results.
• Misinterpretation may occur. While anyone can operate the machinery, a qualified health professional is best to interpret the results.

Conclusion:

Bioelectrical impedance analysis(BIA) is a quick and painless way to get a read on your body composition. It’s accuracy is on-par with other practical body composition techniques. If you have the chance to have this test done, I would recommend it!

Joanna Kriehn is a Registered Dietitian Nutritionist and Certified Diabetes Educator with a passion for supporting individuals as they move towards a healthier lifestyle.

Underwater weighing is a traditional and reliable method of measuring body composition.

Underwater Weighing

Underwater weighing, also known as hydrostatic weighing, is a method of calculating body fat percentage based off body density. Underwater weighing takes place in specially designated pools and/or water tanks designed for hydrostatic measurement. The test is usually only available at universities, research facilities, and some fitness centers.

How does underwater weighing work?

Before the underwater weighing takes place, the individual being measured will be weighed outside the water. Then, wearing a bathing suit, the individual will enter the pool or tank and sit in a chair that is submerged in the water.

The chair will either be lowered further into the water or the individual will be asked to lower their head into the water until their entire body is submerged. Once submerged, the individual exhales as much air from their lungs as possible by blowing bubbles.

The test administrator records the weight when no more air bubbles appear in the water and the individual can then resurface. The test is typically repeated several times and the average of the weights used to minimize errors.

The recorded weight will be plugged into equations that account for any leftover air in the lungs and gastrointestinal tract to calculate body density in water and total body fat percentage.

How accurate are the results?

Underwater weighing is considered one of the most accurate forms of measuring body composition. Rate of error for underwater weighing is estimated at 1-3%.

Underwater weighing was once considered the “gold standard” for comparing accuracy and reliability of other body composition measurement methods. However, with newer technologies available, it’s being used less often since it does require special equipment.

What are optimal testing conditions?

The individual being weighed should be comfortable getting in and out of a pool and/or tank of water while wearing minimal clothing, such as a bathing suit.

The individual should also be capable and comfortable expelling air from their lungs and keeping still while submerged underwater.

Pros of Underwater Weighing:

• Underwater weighing is highly accurate with one of the lowest margins of error.

Cons of the Underwater Weighing:

• It’s not the ideal choice for everyone, since it requires fully submerging yourself underwater. Some people may not be comfortable getting into water or lowering their head beneath the surface.
• The equipment used for underwater weighing isn’t widely available and/or accessible.
• The test may be an out-of-pocket expense to the individual being weighed.

Conclusion

Underwater weighing is one method for calculating percentages of body fat and lean mass. Although highly accurate, it is not widely available, and therefore, may not be convenient for taking regular weight measurements.

Other methods, such as bioelectrical impedance or skinfold measurements, may be more convenient for tracking changes in weight and body composition.

Ana Reisdorf, MS, RD is a freelance health writer and dietitian with 12 years of experience in the field of nutrition.

You are not alone!

The stress from trying to juggle so much is very common, but balance is possible! Use these 5 TIPS to help get on the right path to a happy and healthy lifestyle.

1. CREATE A WEEKLY SCHEDULE – Find an hourly planner and schedule in your day. Start with the usual suspects: morning routine, work day and dinner/night routine. Then take the in-between hours and make them count! Add in an hour a week for a massage, 30 minutes a day for reading, 45 minutes/day for a workout, etc. Find what FILLS YOUR CUP and mark it in pen! The most important part after you do this is to STICK TO IT as much as possible. When you’re with your family – be with them and not distracted by work, phone, etc. When it’s your “me time” make sure you take it! Need some ideas?
2. LET GO OF THE GUILT – Do you feel guilty because you’re working so much or having to put your child in daycare? Instead of focusing on feeling bad, remember WHY you are working so hard and what it is providing you and your family. Some days are always harder than others so try and find another parent to connect with on those days you may need a little extra support.
3. PLAN SOMETHING FUN – Once a month plan a fun family get-together. Go visit family, visit a museum or try out a new park. Experiencing new things together creates memories and gives you new things to talk about and connect with.
4. START EACH DAY RIGHT – Plan the night before for a flawless morning routine and your day will go much more smoothly. Try laying out clothes and making lunches the night before. The morning of, take 5 minutes for a morning mantra meditation or to envision your successful day and then go for it. What you you in your 1st hour of the day can dictate the next 23 hours!
5. SCHEDULE IN DATE NIGHTS – Having time for just you and your significant other is JUST AS IMPORTANT as having family time and alone time. Get a sitter and do something fun! Use this time to reconnect and let loose and enjoy your kid-free time….bonus points for not talking about work or the kids!