Weighty Issues

The scale is perhaps the most feared piece of equipment in the gym (with the possible exception of the the Assault Bike!!). Everybody dreads stepping on the scale, as if they are about to drop into the abyss.

So here's my take on scale weight, why it can be a useful measurement tool, and why you have to exercise some caution when using it.

"A frequent pattern is that if weight goes down, that means it's time for celebration. Bring on the cake. But if weight goes up, it's time to reduce food intake even more and add an extra hour of exercise to the gym. As you'll see below, these types of short- term changes are relatively meaningless overall" (McDonald, 2018)



In terms of weight gain or loss, it is important to note what factors can influence this: -

1) Water/Glycogen/Food Residue: Almost without exception, short term changes in weight represent changes in water, glycogen and food residue. For example, dietary carbohydrate can have a massive impact on scale weight due to the fact that for every 1g of carbohydrate ingested, 3-4g of water is stored with it. Therefore eliminating carbohydrates from the diet will see a rapid drop in bodyweight which will come from loss of water and stored carbohydrate in muscle tissue (glycogen).

2) Fat and Muscle: Changes in fat and muscle will occur over longer time periods than shifts in water and glycogen. A 1-1.5kg drop in weight across a day will almost certainly all be from changes in water. However, that same change over 2-3 weeks will much more likely represent an actual change in body composition from reduced body fat or muscle.


If you are going to use scale weight as a measure of body composition progress, apply the following rules: -

1) Weigh yourself EVERY DAY: Keeping a weekly average helps to iron out day-to-day fluctuations in weight that have absolutely nothing to do with body fat gain or loss. All you need to track is whether the weekly trend is flat (maintenance of body weight), going upwards (weight gain) or going downwards (weight loss).
Weighing daily has also "acts as an immediate reminder that she is attempting to change her eating or activity habits and that along helps with adherence. Daily weighing and feedback was also shown to help college aged women avoid the normal freshman year weight gain that tends to occur by giving them better feedback. Regular monitoring of body weight has also been shown to help with long-term weight maintenance" (McDonald, 2018)

2) Weigh yourself in consistent conditions (first thing in the morning, naked is perhaps best as clothes can weigh 0.5-1kg). It is impossible to compare weight taken at 6.00am on an empty stomach having just been to the bathroom vs 6.00pm after eating normally throughout the day and having drunk 3 litres of fluid. Always:
-Weigh at the same time
-On the same set of scales
-Under the same conditions

3) (For Females): Pay more attention to monthly weight averages as weight can fluctuate across your monthly cycle mainly due to water retention. Lyle McDonald's excellent book "The Women's Book" discusses the nuances of the female cycle in great detail. Here is an example of how it can affect scale weight across the month: -

Month 1:
Early Follicular - 143lbs
Late Follicular - 147lbs
Early Luteal - 145lbs
Late Luteal - 150lbs

Month 2:
Early Follicular: 141lbs
Late Follicular: 145lbs
Early Luteal: 143lbs
Late Luteal: 148lbs

Month 3:
Early Follicular: 140lbs
Late Follicular: 144lbs
Early Luteal: 142lbs
Late Luteal: 147lbs

You can see that for females, comparing different weeks within the same month is fraught with difficulty due to the changes in water retention brought about by hormonal fluctuations. Perhaps the best way for females to truly track changes in body weight would be to compare one week of the month to the same week of the following month. In the example above, you could compare the early follicular phase each month to see that weight decreases by 3lbs across the 3 months (143lbs to 140lbs).

"comparing only like weeks of the cycle to each other will give a much better indication of what is happening than trying to compare weeks within the same month." (McDonald, 2018)

4) Use at least 2 means of tracking progress. Why? Well, all methods of assessing changes in body composition are inherently flawed and have varying degrees of accuracy. Therefore using 2 methods tends to average these inaccuracies out and give a more complete picture of how one is progressing. 


1) DEXA Scans: Perhaps the 'gold standard' in terms of methods available to the general population. The DEXA will give an accurate reading of not only body fat, lean mass but also bone density. 
2) Callipers: These can be used in a variety of ways with varying levels of accuracy depending on quality of the callipers, the experience of the person taking the measurements and the number of sites used to assess body fat. 
3) Tape Measurements: During a diet, a decrease in circumference generally indicates body fat loss. The important point to note here is that measurements can decrease even in the absence of a change in scale weight. This is because muscle is denser and takes up less space than body fat. So someone who is gaining muscle and dropping body fat may see no change on the scale but reductions in tape measurements.



4) Progress Pictures: Like all measurements, consistency of measurement is key with progress pictures. You should use the same spot, with the camera the same distance, wearing the same clothing. Different lighting can greatly alter the way your body appears.
5) Clothing Fit: This is similar to the use of tape measurements. You can use specific types of clothing to determine how it is fitting. If it is fitting looser then body composition is likely to be improving.

So there you have it. Scale weight shouldn't be something to be feared. Short-term fluctuations should not be regarded as anything other than shifts in water and glycogen. In order to get the most from using the scales, apply the following: -

1) Use scale weight in conjunction with other methods of tracking changes in body composition

2) Weigh yourself daily, under the exact same conditions

3) Females please use caution when comparing weight week to week due to the monthly cycle. It is perhaps best to compare weight monthly to assess actual change.