When you’re trying to get healthy, the scale can be your biggest enemy or the scariest monster under your bed – literally, if you keep yours there like I did. The numbers on that display can dictate whether you’ll feel good or bad about yourself on weigh-in day. I used to step on my scale once a week with a shiver of trepidation. Would it bring good or bad news? Could I have a piece of toast for dinner or was it going to be plain chicken and broccoli again?
Fortunately, this doesn’t have to be your life just because you want to get a bit more in shape. When you get to know the science behind the numbers on the scale, you’ll start to see it as no more than one of many helpful tools in your fitness toolbox.
The weight registered by the scale is your total body weight, the sum of water, fat mass, and fat-free mass, that is bone, muscle, and organs. Your body fat, muscle mass, and water content are subject to daily and even hourly changes, so it makes little sense to put much stock into a single measurement. According to research, the amount of water stored in your body fluctuates throughout the day and can vary by up to 5% on a day to day basis. Considering our bodies are about 50%-60% water, depending on gender, a 5% difference can have a big impact on your scale weight! In fact, a recent study demonstrated that variations in fat-free mass and especially in water composition appear to be the major culprits for short-term weight differences.
Food intake and regularity will also influence your weight throughout the day, so you may be a little heavier in the evening than in the morning on a given day. Not only that – a single meal can add several pounds to the scale the next morning. For example, I once “gained” three pounds the morning after eating at Nando’s. There’s no need to panic. One pound (about half a kilo) of body fat is equal to around 3,500 calories in excess of your daily caloric needs, so it’s unlikely you got “fat” from last night’s dinner at your favourite restaurant… unless you ate the whole restaurant. As for my Nando’s meal, I don’t use salt, so the higher sodium content in that cheeky goodness caused me to retain more water than usual. Mystery solved!
Lastly, if you’re in a female body, your period can alter your weight. For this reason, even if you’re already tracking your weight over time without worrying about short-term variations, be aware that your results will be out of whack during “shark week”.
A scale can help you track your long-term progress, but it’s pointless to get bogged down in ultimately meaningless short-term changes.
To get an accurate measurement over time, it’s best to weigh yourself first thing in the morning, naked, after a visit to the toilet. Many experts, including psychologists and scientists, advise to do it only once a week, as daily weigh-ins can become an obsessive-compulsive behaviour, associated with poor body image and decreased self-confidence.
However, my own relationship with the scale improved when I started weighing myself every day instead. Seeing the weight go up and down regularly helped me understand the insignificant impact a single weigh-in has on the overall trend. At the same time, I wouldn’t have been able to benefit from this knowledge years ago, when gaining a pound “overnight” would have made me restrict my food intake the next day. Everyone should be honest with themselves and pick the frequency that best suits their goals and mental health.
Complementing weigh-ins with a different tool can also be beneficial to put the results into perspective. A cheap and easy alternative is to measure waist circumference after stepping on the scale. For instance, the day after my dinner at Nando’s, though my weight had increased, my waist size stayed exactly the same. Other helpful tracking methods you can easily implement at home include monthly comparison pictures and skin fold body fat measurements.
In the end, the scale is only an instrument to achieve your goals. It’s powerless. You’re the only one holding absolute control over your own health.