When I discuss nutrition and weight management with my patients and their parents, I am always careful to discuss how to measure progress. Remember, children are continually growing with regards to both height and weight. Also, peak muscle/bone mass is achieved after puberty. All of these factors make it tricky when your child steps on the scale and you are trying to decide if the number is acceptable or not. In fact, “weight,” is essentially a meaningless number. Remember the term “density.” That is more important. Fat is less dense than muscle. Body Mass Index, or BMI, as a measurement, is a better tool in tracking your child’s health. Although BMI is not perfect (it does not differentiate between muscle mass and fat mass,) this is what I use in the office. It is superior over “weight” as a tracking measurement. Especially if it is measured over a period of time – preferably over the course of 2-3 years to get a feel for the rate of change. BMI is much easier to calculate on an everyday basis now that we use computerized electronic health records.
At home, I believe waist circumference gives us the best measure for tracking progress in children. Waist circumference gives us a better idea as to how much fat is around our middle – also known as visceral fat. Renowned pediatric endocrinologist Dr. Robert Lustig discusses the importance of visceral fat in his new book “Fat Chance.” You can measure this informally by keeping track of pant waist size or belt size. You can also measure with a tape measure. On the Dietdoctor.com website, Dr. Eenfeldt recommends the best way to do this (see #4 – measure your progress). He states:
“Here’s how to do it:
Put the measuring tape around your middle, slightly above your belly button (to be exact: at the midpoint between your lowest rib and the top of your hipbone, at your side).
Exhale and relax (don’t suck in your stomach).
Make sure the measuring tape is snug, without compressing your skin.
You can remeasure every 3-4 weeks to monitor your change when using the LCHF approach.
When my teenage patients come back into the office for follow up visits, sometimes their weight has not changed on the scale. Occasionally this brings them to tears until I ask them what has happened to their belt size or waist size. If they have been following LCHF their waist will shrink. After they realize this, the tears stop and they understand their success. In the case of my pediatric patients, the lack of weight change may result from increasing height as well as a change in the muscle/fat composition. In the office, I can also show them how their BMI measurement has changed so they can see their wonderful results!