The kitchen scales are the compass that guides us day by day, the north star that keeps us to a true course. Without it we will tend to wishful thinking and drift onto the rocky shallows of indulgence. Compared to the bathroom scales the ones in the kitchen plot a course that is more timely and of higher resolution, giving us the chance to respond and not just react. Body weight can fluctuate wildly from day to day and even week to week making true patterns hard to discern among the randomness.
Think of calorie counting as the quick melody and bodyweight as the slower bass notes and focus on the first even if remembering the other in the background.
By eating mostly at home and giving processed foods no harbor there food quality has nowhere to go but up. In orienting life patterns away from eating as a form of recreation they become instead a scaffold for productive living, a framework to build habits of health.
The two main physiological processes that affect day to day weight changes are glycogen-water and sodium-water. It’s good to be aware of these otherwise weight tracking may be confusing and even exasperating. Several days of a large calorie deficit will run down the body’s stores of glycogen, a form of short term energy stored in the liver and muscles. By itself this wouldn’t change weight much but the glycogen is bonded with water which does effect it. It’s important to understand the body has shed water not fat so once back in equilibrium bodyweight hasn’t really changed. After just three days of calorie restriction this phantom glycogen/water weight loss is 4-5 pounds. Worse there is a rebound effect when normal intake is resumed as the body has now been trained to hoard glycogen in case of further restriction. After this the body may be heavier than at the start! Marathoners discovered and started using this effect in the 1960s to improve performance – “carb loading” by carrying more energy for the later stages of the race. Body builders also use it to a degree by pumping up their muscles with water – “hydro-trophy”.
Sodium also draws water into the body – why we’re thirsty after eating it and why it increases blood pressure. A low salt diet will lower body weight a couple of pounds quite quickly and the reverse will happen of course. Boxers use this effect and restrict salt to make the weight at weigh-ins.
So most short term swings in weight readings are due to water; glycogen, sodium or even mild dehydration overnight. It’s best to weigh the body at the same time of the day – preferably upon rising – for this reason.
The body cannily reduces energy spending – as it rationally should – in response to a cut in intake by turning down its thermostat, lowering internal temperature and metabolic rate. A daily deficit of 100-200 calories may not be a deficit at all after a month or two.
The overall lesson is to think long term – months or even years rather than days or weeks – when measuring both intake and its bodyweight result.