Victoria Song, senior reviewer at The Verge and the author of Optimizer, the publication's weekly consumer health and wellness newsletter, argues that accuracy in health tracking is sometimes overrated. Her evidence is a clinical encounter from about three years ago in which a doctor prescribed a specific outcome no consumer wearable could have identified: lose approximately five pounds of visceral fat stored above the belly button, to address borderline high cholesterol. Song's weight was not the issue, her BMI was not the issue, and her subcutaneous fat — physically pinched on her lower abdomen — was not the issue either.
The Distinction That Matters Is Not Being Tracked
Visceral fat and subcutaneous fat are not interchangeable clinically, and Song's case makes that plain. Subcutaneous fat is the visible, pinchable kind. Visceral fat sits deeper, around the organs, and its accumulation carries a distinct metabolic risk profile — in Song's situation, one connected to borderline high cholesterol. The doctor's instruction was precise: target a specific quantity of fat in a specific anatomical location. Broad weight loss was explicitly not the goal.
Consumer health trackers — fitness wearables, smart scales, body composition monitors — do not draw this distinction for users. Song's clinical insight arrived not from a device but from a physician who knew which number actually mattered and why.
Accuracy as a Marketing Claim Versus a Clinical Variable
The consumer health device market has competed heavily on precision: tighter heart rate algorithms, more granular calorie accounting, finer sleep-stage detection. Song's Optimizer column, which covers this market weekly, frames a quiet challenge to that positioning. Precision in measurement is only as useful as the relevance of the thing being measured. In her case, the variable that mattered — visceral fat above the belly button — was not something her devices surfaced at all.
Song credits a decade of running for what she describes as apparently beefy legs, which her doctor left entirely alone. The clinical pinch test that identified the visceral fat problem cost no subscription and required no firmware update.