Body Fat vs. BMI vs. Weight

What’s the best way to measure progress?

 

By Andrew Middlenton, Director of Education, E Squared Health

When it comes to measuring the status of our health, it’s easy to rely on one simple metric — weight — to determine if you’re making progress, if you’re healthy, and sometimes even if you’re happy.

Most clients at Titanium Performance are focused on goals like getting stronger, leaner, building lean mass, and losing body fat. Unfortunately, stepping on the scale is not necessarily going to help you understand if those things are really happening. Titanium Performance partners with E Squared Health, a team of nutrition, coaching, and medical experts to give clients access to more resources needed to see short and long term success with their goals. The E Squared Health Wellness Studio provides clients with the ability to look beyond the scale and learn more about their overall body composition, lean mass, fat mass, inflammation, hormone balance, and stress levels to look at their progress in a whole new way. Specifically, we use technology called a Styku 3D body scan to give clients a chance to learn what their “weight” is made up of, and better understand the body composition and how it is changing over time. 

Neither weight, nor BMI, nor body fat are good or bad, they’re just different. Understanding the difference between body fat percent, body mass index (BMI) and weight can help you better understand these different tools and how they may (or may not) be the best way for you to measure your progress. 

Metric:  Weight

How it’s measured:  A scale

We know that weight is the easiest, and the most common way people measure their progress, but it really doesn’t tell the whole story, which can lead to feelings of frustration. A pound of fat is equivalent to 3500 calories. Let’s say, for example, that you go out to eat the night before and have food that tends to be pretty salty, like a big bowl of Chinese food, or a bunch of chips and salsa at a restaurant. The next morning you wake up and your weight is up 3 pounds. You might feel really upset or frustrated. However, you would have had to consume 10,500 calories to actually have put on three pounds of body fat overnight. It’s more reasonable to assume that you are retaining some water (which holds no caloric value), and that most of that will be gone in a day or two, assuming you don’t continue in a large calorie excess state the next few days.  Hormones around a menstrual cycle, sugary foods, and even being dehydrated can all impact your day-to-day weight, but it doesn’t really tell you if you’re gaining or losing water, fat, or muscle. 

Pros:

  • Weight is a great way to know if you’re in a caloric excess or caloric deficit.  

Cons

  • Your weight can and will fluctuate all day long, up or down. The average person’s weight will fluctuate four to eight points in a day and are typically due to water, inflammation, and the food we eat
  • Fluctuations each day can lead to frustration
  • Does not measure what kind of weight is being gained or lost

Metric:  BMI

How it’s measured:  Calculator using weight and height 

BMI is often used by medical professionals to determine health risks. It is best used to predict the health risks of a population, not individuals. It is often confused with body fat percent. Your BMI can be used to determine “fatness” but often doesn’t do the best job doing this. For example, let’s say two people are the same height, 5’ 8”, and weigh 165 pounds. Person A could have a high body fat percent and be 165 pounds, and person B could have a low body fat percent with a lot of muscle mass and still weigh 165 pounds.  But, both would be told their BMI puts them in the overweight category.

Pros 

  • Good tool to assess risk of a population
  • Not a consistent way to determine fatness

Cons

  • Doesn’t take muscle mass into account (muscle weighs more than fat)

Metric:  Body Composition

How it’s measured:  Various ways to assess

We consider body fat percent, also known as body composition, the best way to measure your progress, especially if your goal is to lose body fat, gain muscle, or both. However, there are various ways to measure body composition, unlike weight and BMI which have one method each.

Pros 

  • Best means of measuring progress if your goals are around dropping body fat and/or gaining lean mass
  • Helps you understand if weight gain or weight loss was due to shifts in fat mass, muscle mass, or both
  • Reduces frustration of “overnight” weight gain

Cons 

  • There are seven different ways to measure body composition, and there can be a high degree of variability between each method 

Methods of collection for body composition:

DEXA scan 

Pros:

  • The most accurate method to collect body composition measurements

Cons:

  • Extremely expensive device
  • Requires a radiologist to conduct the scan
  • Administers small dose of radiation

Styku Scan

Pros:

  • 98% accurate (about as accurate as a DEXA scan)
  • Minimally invasive
  • Short assessment time (35 seconds)
  • Provides circumference measurements for the whole body each scan (measurements are 20% more accurate than a tailor)
  • Monthly scans provide analysis of changes in lean mass, fat mass, circumferences, visceral fat, bone density, posture, risk analysis, and basal metabolic rate
  • Best marriage of price, accuracy, and client experience and satisfaction

Cons:

  • Can be hard to find places to do them because they require a dedicated space

Bod Pod

Pros:

  • 92-93% accurate
  • Minimally invasive

Cons:

  • Very expensive
  • If the client is too large, they can’t fit in it
  • If you don’t expel 100% of the air out of your lungs it won’t be accurate

Hydrostatic Weighing

Pros:

  • Can be safely used for people who are pregnant or have pacemakers

Cons

  • Can usually only be done on university campuses
  • You must be submerged in water and have to expel all air from lungs for it to be accurate

Skin Fold

Pros:

  • Safe
  • Very inexpensive
  • Good tool to monitor progress over time, but not very accurate
  • Can be done pretty quickly

Cons:

  • Does not measure visceral body fat (to have an accurate measurement, you need to measure visceral and subcutaneous body fat)
  • Very invasive
  • Human error, even with a tenured coach
  • Usually need another person to administer it
  • Influenced by hydration status

BioElectrical Impedance Analysis

Pros: 

  • Minimally invasive
  • Quick to administer

Cons

  • Up 15% degree of error
  • Heavily influenced by hydration, clothes that you’re wearing, if you’re sweating or not, full bladder

At Titanium Performance you can work with your trainer and an assessment provider from E Squared Health to measure and track your body composition over time to get a true picture of the progress you’ve made. Body composition measurements can also help your trainer know if and when it’s time to pivot with your training plan. Clients at Titanium Performance can receive a complimentary initial assessment which includes a Styku 3D body scan at E Squared Health at any time. E Squared Health also provides support with nutrition and lifestyle goals. Learn more and sign up at esquaredhealth.com