If there's one thing I love, it's that morning moment when I step on the bioimpedance scale and wait for the verdict, as if it were a modern oracle of physical fitness. Gone are the days when a mirror or a pair of tight pants were enough to tell whether it was a day of celebration or penance. Today, we have numbers, graphs and technological promises. The problem? These numbers change more than my patience for fad diets.
The Illusion of Domestic Science
The promise is simple: an electric current passes through the body, measures the resistance and, as if by magic, delivers a detailed estimate of body composition. Fat percentage, muscle mass, body water – all there, on a bright and seemingly reliable display. But… is it really?
After a month of vacation between pizza and ice cream, the scale decides that I'm thinner than ever. So I get back on track (regular diet and exercise), and it shows an inexplicable increase in my body fat percentage.
The Big Problem: Surreal Variations
1- The mood of the scale changes with your hydration
• Drinking more water can make you a Hercules.
• Losing fluids after a workout can turn you into a supposed fat accumulator.
2- What you ate also comes into the equation (even if it shouldn't)
• A salty meal and voila, you're "retaining more fat" (or is it just water?).
• Cutting down on carbs? Congratulations, you’re losing weight – but probably just less stored glycogen.
3- Each scale has its own guess
• Numbers vary from device to device, and it seems that some scales are more optimistic than others.
4- The internal thermometer also controls this
• After a hot bath or after a workout, your blood circulation changes its reading, and suddenly you are a new man or woman.
Alternatives for Those Who Want Less Drama
If you want to track your progress without the rollercoaster of numbers, here are more reliable options:
✔ Bone Densitometry (DXA), with the disadvantage of being quite inaccessible
✔ Skin folds, as long as a professional takes the measurement.
✔ Photographs and measurements: Sometimes an honest mirror says more than any algorithm.
Conclusion: A morning game of chance
Bioimpedance scales can be fun – if you enjoy a morning game of chance. But making decisions based on them? Bad idea. If your body composition changed at the rate these numbers suggest, you’d be a bodybuilder and a Michelin star in a single week.
So next time the scale tells you that you've gained 2% body fat overnight, remember: it could just be a technological quirk. Or maybe you just drank one glass of water too many.
Rita Gomes - Personal Trainer BMS