Starving Dietitian

Lessons Learned From 182 Weigh-Ins


Digital Health is here to stay and by most predictions will be one of the defining technology movements through 2020. For those that might not recognize the term, digital health is the coming together of technology, computers, data, and the entire Health field. What this means for us is difficult to pinpoint, but an example would be pairing gene testing with a specific diet, or letting your doctor access your Jawbone Up data to make better suggestions. I’ve mentioned the former in my post The Gene Prescription if you’d like to read more on that.

In the past I’ve looked back on Fitbit data and argued that mindlessly tacking a number onto something like sleep time or steps taken only adds to our Quantified Guilt unless we have the professional guidance or tools to make a positive behavior change. Today I’d like to take that one step further.

Unsatisfied with the current health dashboards the only option was to take it upon myself to build a better tool. With just a moderate background in Spreadsheets I was able to build a tool that not only grabbed my daily weigh-ins from my Withings WiFi scale, but also plugged in height, age to the day, and activity level. The outcome of all of this was a tracker that allows me to see my daily calorie needs using the Mifflin St Jeor Equation.

Now on to the good stuff, what I’ve noticed.

1. You need less calories than these formulas give. 

Just looking at the calorie calculations I was surprised just how many calories I was estimated to need. I’ve done Mifflin calculations before but there’s something to be said for seeing your unique calories needs each and every day. It was often much higher than I know that I eat, which makes me question who this formula is accurate for. If you do rely on an app to calculate calorie needs, I recommend scaling down by about 10%.

2. Most weight variation comes down to very few calories. 

In a little over a year my weight averaged plus or minus 4lbs. That seems like a pretty significant difference if taken together (8lbs) but in actuality the tool showed the difference was only 50 calories per day from lowest to highest weight. To put that in simpler terms, that’s about 17 grapes.


Which leads to the next point.

3. The body is very good at trying to maintain weight.

Since I started tracking my weight like this the variation has consistently stayed around 2.5%. That includes a honeymoon, a significant change in exercise, the holidays, etc. etc. That is a lot of change to see such small variations. I’m actually surprised that between appetite, exercise, and metabolism that the body is able to maintain such consistency. The smaller the variation, the healthier the metabolism.

4. Daily Weights are a curse as much as a blessing. 

Body Scale Evil Mean

The problem with daily weight is that weight isn’t a great measurement for, well, body weight. That sounds ridiculous I know, but athletes can easily lose 5% of their weight in fluids during a 2 hour sport and a single salt-heavy meal can cause fluid retention for 24-48 hours. Both of these will affect that little number staring up at you. You might see a number significantly higher, do nothing, and see it back to normal in a day or two. This can cause as much frustration as a slowly expanding waist line, so it’s best to stick to weekly weigh ins if you’re trying to lose weight. 

5. Don’t trust a single weigh-in. 

My final finding was that weight is a totally unreliable metric for one-time use. It’s always bugged me that Doctors don’t mind shoes/belts/wallets when taking weights. Paired with what I ate for breakfast or even the time of day, my calorie recommendations from that weight would be worthless. Think how many people have only the doctors scale to rely on. If you do track your weight, it’s best to throw it into a spreadsheet and take the 5-period moving average. It is a much more honest snapshot of how your weight is trending, and whether you should take action.

All in all it was a fun experiment and I’d be happy to do a write-up on setting it all up if there’s the demand. Let me know in the comments if you’re curious! I’ll definitely keep tracking my weight like this as it tells me far more than simply weighing myself and comparing to some ideal in my head. Thanks for reading.

Be good to each other.

– Joshua Iufer, RD

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: