26 February 2020

What the scale is NOT telling you


That number you see on the scale, which induces an immediate emotional reaction—whether it be confronting or joyous— is always taken so seriously and uncompromisingly. All in a single moment. It is over in the blink of an eye, yet it often determines how you feel for the subsequent hours, if not the entire day. …

That number you see on the scale, which induces an immediate emotional reaction—whether it be confronting or joyous— is always taken so seriously and uncompromisingly. All in a single moment. It is over in the blink of an eye, yet it often determines how you feel for the subsequent hours, if not the entire day. 

But what does that number really represent? What can one weight measurement really tell you? And—more importantly—how and why does the number jump up and down so rapidly within only a day or two? 

One thing is for certain; the changes in those digits are not exclusively due to fat tissue—rather, they are the sum of all tissues and fluids that produces the conscious and capable human who is reading these very words. However, we often myopically view any change as inherently related to fat gain (or loss for that matter). And once the scale isn’t acting in accordance with what one desires, it often becomes impossible to fathom and is related to the bottom draw or somewhere else where it is equally unlikely to be seen.

This is unfortunate. 

What you quickly realise once you adopt a consistent weigh-in schedule, is that your weight floats along a changing continuum. It is a continuum because acute and transient variables—such as the ones we will discuss today—determine your weight within certain parameters. 

The range which this continuum covers is changeable however, and this process is governed by the principle of calorie balance. Eating in an energy-deficit over a sufficient period of time may reduce your average body-mass by ~2kg, for example. However, due to the acute factors that influence bodyweight, this may not yet be detectable on the scale, as acute variables can have a large, and almost instantaneous variance of 3kgs or possibly even more. 

So while drops related to acute variables make it look like you’re incinerating fat by the hour, this is often misguided. Just as many are when they conclude, after a sudden stall, that fat loss could not possibly be occurring. Maybe it’s a false negative? Which could be being masked by variables causing acute weight gain. In either instance we must remember that the scale is best used over time, using averages. Daily, and even weekly changes aren’t all fat. Shoot—most of it isn’t.

The law of energy conservation—which the principle of calorie balance is founded upon—simply can’t be ignored. The most likely, if not only, reason you’re not losing weight overtimeis because you’re eating too many calories compared to what you’re expending. 

Unfortunately, “dieting” can feelhard without actually creating a calorie deficit, if you do it right (or wrongly). This situation can easily arise without consistent eating or tracking of calories. It’s hard to know whether subjective measurement align with the objective, if you’re not being systematic in any way.

To be clear, consistent eating is not the principle are fat loss. Creating a caloric deficit is. Consistent eating just allows you to be surer of whether or not you are consuming an appropriate amount of energy for your goals.

In saying that, day to day fluctuations in scale weight are less likely to occur if you keep your total calories and food choices the same. But that alone won’t do the trick. Stress management, consistent exercise/activities all also need to fall in line. 

Understanding that eating in a calorie deficit is required to lose fat tissue, and that this process will reveal itself on longer time scales—however, this doesn’t address the second point that I made initially; that daily fluctuations in weight are only minutely related to calorie balance, and thus to gaining or losing fat. This process is also important to understand, as it often is the thing that derails many a committed dieter. So if the weight we gain or lose on a daily basis is mostly not fat, or even muscle for that matter, what is it?

Before I explain that, let’s first look at a graph that depicts 2 weeks of consistent weigh-ins…

A close up of a map

Description automatically generated

As you can see, (acute) weight was gained on days 5, 10 and 14. However the trendline of the graph shows a steady and significant decline across the 2 weeks and indicates ~1.5kgs was lost in this time (of which, we can safely assume that a decent proportion of was fat).

Graphs like this are insightful, and they often help dieters to understand what is most often misunderstood. Grasping the fundamental concept of averages-over-time and the use of trendlines allows you to change your relationship with the scale for the better, providing a basis for more persistent and sustainable dieting efforts.

To further drill home this point, we can look at some additional pieces of information that are informative regarding short-term weight fluctuations. 

For example, consider the question:

If someone were to eat in a 500-calorie surplus, how many grams of fat tissue could that add up to?

Answering this question will in turn allow us to separate the difference between fat and other mass, and how they impact our daily weight measurements.

While we can’t answer the question exactly outside of a research lab, previous research and a little maths can provide us with a good general understanding and ballpark answer.

An important piece of information here is how much energy there is a kilogram of fat tissue, which is approximately 7700 kcal. So if you eat in a 500 kcal surplus on any given day—and store fat at 100% efficiency, which even in itself is unlikely—you stand to gain around 65g of fat (500/7700 = 0.065).

The end total of 65g is only arough approximation, really is the most extreme upper-end regarding the amount of fat we could possibly gain given a 500 kcal surplus. In almost all cases and situations it will be less. 

The creation of fat tissue from an excess in energy (calories) is in itself an energy expensive process which chips away at the 65g—nothing in the human body gets done for free. 

Another factor working in your favour is that an excess in energy can be stored in different tissues, not just fat, which I’ll explain soon. Another reduction to the original 65g.

In the real world, these approximations become impractical by the impossibility of knowing exactlyhow much of a surplus or deficit you’re in. They are informative however and indicate the relatively tiny percentage of fat that is stored for any given amount of excess energy that is consumed. 

The sole reason I bring this equation to your attention is to show you how incremental fat loss and fat gain really is and how on a day-to-day basis, it won’t significantly influence the change in scale weight. To gain 1kg of fat overnight, you’d have to eat in at leasta 7700kcal surplus. It’d really be way more than that, but hopefully you get the point. 

7700 calories p/d roughly equates to…

– 5-6 Family size pizzas

– 25 McDonalds cheeseburgers 

– 33 servings of Coco pops (60g servings)

I’d actually be impressed if someone could do that which IS NOT a challenge. And let’s not forget that this would have to be on top of your maintenance calories, which will be somewhere between 1000-4000 calories depending on gender, genetics and activity levels. Sometimes more, sometime less, but around that mark.

Once you’ve come to such a realisation, the next logical question then becomes…

If I only eat slightly above maintenance calories, let’s say somewhere between 200kcals but I weigh in 1kg heavier the following day, what is that extra weight?

Well now that you can do the math, you’d recognise there to be a 974g gap. 

Without that knowledge, your thought process after seeing such a drastic rise is likely to be something like: I’ve blown it! 

However, I’m here to tell you otherwise. That gap is explained by all the other storage mechanisms that I’ve previously eluded to. And each presents itself via their own unique circumstances that requires detailed discussion. 

1.Glycogen + Water

When Carbohydrates are consumed, there are 3 possible courses of action. Priority number 1 is to convert carbohydrates into ATP (energy), but without the demand for energy, leading to an excess, it must be stored. Priority number 2 is then to store carbohydrate as Glycogen within the liver and muscles (whilst excess dietary fat on the other hand gets preferentially stored as fat tissue). Once glycogen stores are nearing max capacity, De novo Lipogenesis(the creation of fat tissue from carbohydrate) will initiate and this process is very energy expensive.

Remember when I said it’d likely take more than an additional 7700 kcal to put on 1kg of fat, well it’s because of energy expensive process’ like this, in combination with a large glycogen storage capacity.

Your muscles can store somewhere between 400-800 grams of carbohydrate and our liver also gets in on the act carrying around 80-100 grams. Genes, activity levels, habitual diet and the amount of muscle you carry dictate whether you’re at one end of the spectrum or the other. Regardless though, that’s a fair whack of carbohydrate storage capacity.

Here’s the real mindblower though: Each gram of carbohydrate binds to 3 grams of water.

Glycogen = 1-part Carbohydrate + 3-parts water 

To put this in perspective , if you store a total of 500 grams of excess carbohydrate, you inherently store an additional 1500g of water alongside that carbohydrate withinthe muscle. Leaving you with a total of 2kgs (500g + 1500g) in added mass. Mass that doesn’t make you look fatter, rather it makes your muscles look fuller!

Through this combination of carbohydrates and water, glycogen loading can lead to 3.6kgs or more of extra weight. Conversely, once storage is full, a full depletion could see the equal loss of that weight. A 1kg drop through this mechanism alone just by eating significantly less carbohydrate is entirely possible after only a single day.

Anyone that has endured a low carb/ketogenic diet for even one week will have likely experienced a large initial drop in glycogen, depending on their starting level. This is not to be confused with fat loss though. Without habitually eating a similar number of calories and/or carbohydrates, significant day to day fluctuations can occur without reliable indications of fat-loss.

2. Cortisol related water retention 

Restricting foods over time can result in the accumulation of stress. People tend to self-inflict stress by following unsustainable and unhealthy methods but even for those dieting in an educated fashion, you’ll still see some stress accumulate over time. 

Cortisol for all intents in purposes is much more than just a “stress” hormone but for the purposes of this article, being weight fluctuations, I’ll only refer to it through that lens. 

The key mechanism you’ll need to know is that cortisol interacts with aldosterone receptors within kidneys—the area of the adrenal glands that regulates fluid balance.

To put it simply, elevated levels of stress cause a rise in cortisol, leading to water retention via the adrenal glands. 

Fat loss is not blunted at this point, granted you’re still in a caloric deficit but it can easily be masked on the scales. These improvements can remain hidden for considerable amounts of time and until you can get your perceived or physiological stressors down, your efforts shall remain “unrewarded”.

Often, after or during tough periods of dieting, you’ll have to manage stress by returning back to maintenance calories or beyond. This is where something seemingly extraordinary can occur. It’s known as the “whoosh effect”. As I said before, stress can rise significantly throughout a dieting phase and by lowering that stress with more food, you can sometimes achieve a drop-in scale weight. This is where a lot of coaches advertise—somewhat misleadingly—client who they’ve given more calories to eat, but they’ve lost more weight.

This is not to be confused with the thought of you losing weight on higher calories, No, it’s your previous efforts finally revealing themselves with the diminishment of stored water. 

Looking at stress from only a deficit related point of view is too narrow-minded. We all let stress accumulate, regardless of whether we are even trying to lose weight. Additionally, hopefully you can reduce stress this without the need to eat more food. However, it is sometimes the case, especially for any very lean individuals, that more food will be required to significantly reduce stress levels and thus cortisol related water retention. 

Psychological stress is only one side of the coin though. Physiological stress also bears the potential to put the blinders on your efforts. Any athlete, whether that be a powerlifter, bodybuilder or marathon runner will have intensive phases within their training. Post training stress is a necessary part of the recovery process (inflammation). This inflammation does result in the holding of additional weight, but if you want to maximise adaptions then trying to reduce inflammation becomes counterproductive.

The antidote is to periodically de-load/taper, combined with applying universal stress/fatigue management strategies like eating enough nutrient dense and total food, sleep and several forms of mental training.

3. Intestinal Mass 

Hopefully this goes without saying, but food adds weight to the GI Tract. A day of eating any amount of food that literally weighs more than your habitual intake, is very likely produce a heavier weigh in the next day. 

Ever been timed out of a 2-hour buffet eating reservation and proceeded to weigh in 5kgs heavier the following day? Well I have (not something I’d recommend). Following this effort, it TOOK 1 ENTIRE WEEK for my weight to normal. Admittedly, I didn’t eat much the following day, but after that all the following days were back to standard eating. Your intestines—which when fully stretched out are the size a tennis court—can compact and store a lot more food than you realise.

I once witnessed a conversation that went like this…

Person X “ I’m up 400 grams today”

Person Y “ Don’t worry, you’re one poop away”

Person Z “ Yeah no shit…”

Ok Person Z didn’t actually exist, I made them up, but the rest is true and highlights another additional and important point.

Not only can consuming more food in grams produce a heavier weigh in (in the short term) but a day or two without bowel movements may yield similar results. 

We also can’t speak about intestinal mass, without considering fibre intake. A change in total fibre intake, as well as the type of fibre will have an effect on transit time. Soluble fibre, found in oat bran, nuts, seeds, beans lentils, peas and more tend to slow down transit time. Insoluble fibre found in vegetables, fruit, and wholegrain foods will speed things up. Bear in mind that most of these foods often contain both, so practically the most important thing is to hit a total of around 10-15g per 1000 calories. That’s going to be around 20-30g for most people.

Lastly, one adaptation to hard and/or long-term dieting is the slowing down on bowel movements. This is the ensure maximal assimilation of supplied nutrients for energy as well as the need to supply less hunger signals due to having a fuller stomach and intestines. Understanding this reality can also give you some more clarity in regards to why the scale isn’t dropping like it was.


This trio of factors—glycogen, cortisol-related water-retention and intestinal mass—all fits under a category known as Lean Body Mass (LBM). Which is basically any mass within our body that isn’t fat.

Of course, these aren’t the sole determinants of bodyweight change, but given a short timeframe, they dominate.

There still are other factors to consider, however they tend to be exceptionally slow, such as muscle growth, or are relatively predictable/trackable, like the menstrual cycle. Once you have rough idea of what your weight does in relation to your cycle, you do not need to continue to feel frustrated when your weight spikes at the same point each time. 

Once you understand the three hypervariable components of LBM that I mentioned above, I hope you can see how an inconsistent lifestyle (mismanaging stress, irregular eating patterns etc.) can give you some very sporadic readings on the scale. 

Even typically rational people off the scale, can turn irrational once the scale deviates past their comfortable mental threshold. If this seemingly inappropriate fluctuation is reacted to in a purely emotional and unreasoned manner, it can easily de-rail any remaining motivation for weight loss or even maintenance. 

You may have eaten an extra 150g of carbohydrate, stress out about an upcoming meeting, after having accumulated a ton of physiological stress from overtraining. Maybe you only exceeded your maintenance calories by a 100 calories, or maybe you didn’t, but you consumed heavier foods that contained high amounts of insoluble fibre and all within a 24 hour window. 

BAM, you’re now 1.5kgs heavier, maybe more, and this doesn’t necessarily dissipate after just 1 day.

That’s the thing with stress, glycogen or intestinal fibre accumulation, it can all happen so quickly, but it can take days or even up to a week to subside. 

While this can be frustrating, the real catastrophe comes when you misinterpret such an event and decide to throw in the towel.

You literally couldhave been a day or two away from seeing the scale plummet back to something that makes more sense. BUT your emotional reaction and irrational behaviour that followed didn’t let that happen, did it?

A close up of a map

Description automatically generated

You must be patient. As they say; good things come to those who wait. If you give up every time something doesn’t go your way, you’ll never get anywhere. And that obviously doesn’t just apply to weight loss.

REMEMBER: A single day isn’t enough evidence to suggest it’s all gone pear-shaped, nor is two or even three. 

The choice is yours though—wait a little longer, or give up all hope… 

A screenshot of a map

Description automatically generated

It is entirely possible that you’re eating too much but only timewill tell. And in that case, just revise the plan. Once you know for sure that you’ve been eating too much, you at least have a reference point to base future changes upon.

This pendulum swings both ways however, and it must be acknowledged. Equally dangerous to short-term stalls or spikes, are exceptionally large drops, which are equally explained by changes in the aforementioned factors. With the right adjustments, you can wake up the next day having lost 1.5kgs of weight, without creating the required deficit to change fat-mass to any significant degree. Shoot, you can even eat in quite a large calorie surplus, store a small degree of fat and still lose a lot of “weight” for a day or two if you make extreme enough nutritional changes. 

The lesson here is basically the same as mentioned earlier. Fat has ~7700kcal/kg. Even if you didn’t eat for an entire day, you probably only burned through about ~2000kcal, which is about ¼ of a kilogram of fat. So, when you wake up 1.5kgs lighter some days, remember that you didn’t drop all that weight from fat, and your weight may swing upwards again when you regain some LBM. 

This is why it really grinds my gears when coaches or nutritionists go around claiming that any and all declines in weight are as a result of fat loss. This approach, whether knowingly wrong or not, is a double-edged sword. You’ll be trilled by the highs, like losing 1.5kgs over night, BUT how are you going to explain the reverse outcome? 

It is often (but not always) my experience as a coach that people lose large amounts of weight at the beginning and it slowly declines of the following weeks.

For example, 5 weeks of dieting might look something like this…

Week 1: 88.8kgs

Week 2: 87.8kgs

Week 3: 87kgs

Week 4: 86.7kgs

Week 5: 86.3kgs

Let’s say that the starting calories are aiming at creating a 200kcal deficit per/day.

Over the span of a week, this person has created a 1400kcal deficit. When we extrapolate this out to 5 weeks, the theoretical deficit is 7000kcal. That’s still less than the amount of energy stored in a kilogram of fat, yet they lost 2.5kgs. 

Once you consider the loss of glycogen, intestinal mass, and a potential drop in stress which tends to subsequently increase mood from losing weight, these results become comprehensive.

What I’m arguing is that a coach or nutritionist should explain this after week 1, or from the very outset, especially if the diet of choice is Low Carb/Ketogenic. 

By being honest, open and upfront about all the things that play into scale weight, you will save your client (and yourself) from certain psychological headaches. In addition to this, by taking this approach, your client will very likely respect for your knowledge and honesty. You aren’t helping them by pretending that the massive drop was all due to fat-tissue. 

Lastly, before I summarise, I want to quickly highlight the value of weighing in.

Consistently stepping on the scale, under controlled conditions (first thing in the morning, with the same scale, on the same spot on the floor, wearing minimal and consistent clothing) is crucial data which better informs you of what you need to do when you’re off the scale. 

But for it to be truly useful, it must be completed overtime and in conjunction with other consistent metrics, such as progress photos. Clothing size, girths and many other tools also have their place. Changes in the fluctuating variables that we have discussed today can stall progress on the scale, but with multiple metrics to cross-reference, you can have a better idea of whether you are making progress or not—the scale shouldn’t be your only guiding light.

Another option is skinfold testing, but the tester must be experienced, which is rare, and the process is rather invasive. Nevertheless, it’s still worth considering if you can find a skilled practitioner that you’re comfortable with.

Taking weight is also critical for accountability. After a day or two’s worth of eating large, seeing that number spike is a stark reminder that such behaviour should be few and far between. Receiving this feedback is a useful reminder to return to controlled, strategic eating. Staying naïve and choosing not to step on the scale when “you know you’ve been bad” is dangerous as it can further allow you to rationalise poor eating and exercise habits.

No matter what, the number won’t be different—so step on. The number isn’t hurting you. It’s your behaviours and interpretation of that number is the real problem.


  • Scale weight isn’t just fat. There are multiple ways in which you can add weight to the scale.
  • Scale weight can jump up rapidly after a change in behaviours, but it can take days and sometimes up to a week to return to baseline once you return to standard behaviours 
  • Without controlling variables, you must adjust your expectations. Time then becomes your best friend for weight loss granted you’re in a deficit.
  • Calculating potential fat gain by using 7700kcals as your starting point is only useful to settle the mind. Or just understanding how incremental fat gain is from reading the above examples can and really should be enough.
  • It requires multiple metrics taken properlyand overtimeto get a full picture of body composition changes.
  • Changing your approach to weight management with only 1-7 days worth of evidence is often not enough to go by, especially if you’re already quite lean. 

Your email address will not be published. Required fields are marked *

Send this to a friend