It’s demotivating when your weight increases on a diet, even if you know you’ve made progress. Your clothes fit better, but the scale seems to show fat gain. It’s a common experience, and has lead to an industry of scale condemnation. Headlines like “throw away your scale!” are a tabloid trope.
But the scale is misunderstood, and it’s still the best way to track fat loss when you know how to use it.
Optimizing fat loss requires measurement
We need a way to track fat loss progress so as to make changes when necessary.
Ideally we’d take exact readings of body fat percentage, but there’s no easily accessible way to do it. Therefore we make do with other measurements that normally track with fat loss.
These include skinfolds, limb and torso circumferences. And of course body weight.
Tracking multiple datapoints is good, but I suggest only in addition to weighing with a scale—nothing else is as quick and easy to use, consistent in measurement, and widely available.
The problem with body weight
Even though the scale itself is consistent, our bodies are not. Daily weight varies. It’s affected by many things unrelated to body fat, including ambient temperature, stress levels, changes in activity, time of day, sleep duration, sodium and water intake.
It’s helpful to weigh first thing in the morning with an empty bladder for the best chance of consistency (or at least at the same time every day). But even then weight fluctuations can be large. Which seems to contradict to the point of weighing in the first place. If weight isn’t consistent and doesn’t necessarily reflect fat loss, then what’s the point?
Before you buy into the tabloid hype and throw away your scale, here’s how to make sense of the data.
It’s the average that counts
We can see what’s really happening by observing the trend over days. The average is what’s important, not short term variations.
If average weight is decreasing at the desired rate, you can be confident fat loss is occurring. Conversely, if it’s increasing or static over the course of a week or longer, you need to modify the diet.