The goal is to turn data into information, and information into insight.
In Part 1 of this article series, I explained:
In this second part, I’ll explain how to interpret and utilise your bodyweight data from the beginning to the end of a fat loss phase in order to diet and maintain the results successfully.
As stated in the previous article, the only data that matters in the context of muscle gain and fat loss is your bodyweight average per week and/or per month, which is what I’ll be referring to in the rest of this blog post.
How to use bodyweight data:
Before the start of a fat loss phase
If this is your first time attempting a fat loss phase, start by establishing your maintenance calories.
You can use a fitness formula, or track your current food and work out your average daily calories. Either way, you can use your bodyweight to ascertain whether this number of calories is your true maintenance.
If you get your maintenance calories from a calculator, hit this number for two weeks. If you decide to track your food, do this for two weeks as well.
During this time, if your weight stays within the same small range (generally a couple of pounds), then you’re maintaining, therefore your maintenance calories are accurate.
If weight is trending up, you’re in a caloric surplus; vice versa, you’re in a deficit. You can recalculate your maintenance with a formula that uses the rate in percentage points at which you’re losing or gaining weight (for example, 0.5% of your bodyweight per week). I described this formula in a stepwise fashion in this article under the subheading “Calculating your calories and macros for fat loss”.
Once you know your maintenance calories, you can calculate your initial deficit by subtracting 10 to 20% from this number, depending on how aggressive you want to be with your diet.
For more on how to calculate your calories for fat loss, you can read this article.
The first few weeks in a fat loss phase
For the first two to four weeks of the actual diet, track your bodyweight, but don’t use the data to make any nutritional changes yet.
The reason is that, in the first week or two, you could lose weight faster than you expect based on the calories you’re eating.
This might be motivating, but it’s not all body fat.
In a caloric deficit, most people will have to reduce the amount of carbs they eat, so they can experience a big initial scale drop because they’re losing glycogen (the carbs stored in muscles and liver) and the water that’s absorbed together with glycogen.
The reverse can also sometimes occur, and you could gain a small amount of weight. This can happen if you’re completely overhauling your diet, replacing ready meals, fast food, and processed food with a lot of produce and lean protein, which contain more fibre and fewer calories.
As a result, your portions become much larger and higher in fibre than before. This extra food and fibre take longer to digest, so you may have some left in your gut by the time you weigh in again.
Even when digesting fully, you could still be heavier due to the increase in your dietary fibre, which can’t be processed like other nutrients and will sit in your large intestine after digestion until it comes out from the other side, if you know what I mean.
As a last possible outcome, you could maintain your weight despite the caloric deficit, an exceptional circumstance that I’ll cover in more depth later in this article.
The main takeaway here is that, the first week or two of a fat loss diet, you can’t trust the scale to tell you for certain whether you’re in a caloric deficit, so you can’t make any changes based on its fluctuations.
Instead, trust the process and stick with your starting deficit.
After the first one to two weeks
If we discard the first two weeks of dieting, we need at least two to four weeks of consistent and reliable data in order to establish whether everything is going to plan or whether we need to make any changes.
Scenario A. If after a further two to four weeks (at which point you’ll be between Week 4 and 6 of your diet), bodyweight is trending downwards, then you’re making progress.
The rate at which progress is occurring, is important for a variety of reasons.
In general, “crash diets” that make you lose a lot of weight fast are unsuccessful because such an aggressive approach is unsustainable, and most people end up regaining all the weight lost and then some.
In addition, in extreme cases, losing weight too fast can also result in muscle mass loss as well as body fat.
To avoid these undesirable outcomes, the general recommendation is to lose body fat at a gradual pace of around 0.5 to 2% of your bodyweight per week.
Smaller or leaner people would be better off sticking to the lower end of this range (around 0.5%) in order to prevent or limit muscle mass loss as much as possible.
When you carry more body fat, you’re at a lower risk of losing muscle mass, so you can afford to lose a bigger percentage of your weight per week. Therefore bigger people or people carrying more body fat can aim for the higher end of the range (1-2%).
If you’re losing at a pace that’s within this range and fits with the timeline that you set out to accomplish your goal, you’re on track. Don’t change anything.
If you’re losing too fast or too slowly, you may need to either decrease or increase the size of your caloric deficit. I covered the calculations to do this here.
If you’re losing too slowly, take into account these behaviours that might be hindering your fat loss. Fixing them could help you lose fat more efficiently without lowering your calories. If this doesn’t happen, then you’ll have to resort to a calorie drop.
Make one adjustment at a time, then wait and assess your weekly bodyweight average for at least two weeks to see if the change has the desired effect.
Scenario B. If after a further two to four weeks, bodyweight isn’t trending downwards, then you may not be in a caloric deficit.
Excluding the exceptions described below and some health conditions that can affect your metabolism, if you aren’t losing weight, consider the following steps:
Some notable exceptions to this that I’ve experienced working with my clients are complete beginners to resistance training; people who are getting back into training after several months or years; and transgender and gender-non-conforming people on testosterone replacement therapy.
As mentioned in the previous article, if you’re a complete beginner or if you haven’t trained in a long time, you may be losing fat and gaining muscle at the same time.
If you’re on testosterone therapy, you may experience weight gain or maintenance even if you’re in a caloric deficit, particularly if you started therapy or had your testosterone dose increased around the time you also began your diet.
I have personally experienced some weight gain for a number of weeks regardless of whether I was in a caloric surplus, deficit, or maintenance, at the start of hormone therapy and any time my testosterone dose was raised thereafter.
Under all these exceptional circumstances, reducing calories may not be necessary.
The weight on the scale doesn’t only reflect how much fat you lose or gain, but also the weight of water, muscle, and other components of your body. So, if any of these other components is increasing at a similar rate as your body fat is decreasing, the number on the scale might not budge.
To find out whether you’re losing fat or not under such circumstances, take progress pictures and measurements every single week and compare them to the start of the diet.
If you look leaner, the deficit is working, and you don’t need to change anything. Only opt for lowering your calories if you’re certain that there’s no difference between pictures and measurements taken at least two to four weeks apart.
It’s crucial to remember that the scale is only a measurement tool, not the goal, so, if your bodyweight isn’t changing, but your pictures and measurements are, then you’re on track.
What if you hit a plateau, have more fat to lose, but don’t want to lower calories?
To create a caloric deficit, you need to either eat fewer calories than required to maintain your weight, or do enough activity to expend more calories than this maintenance intake.
However, estimating the calories you eat is overall more precise than estimating the calories you burn during activity, so I would only rely on the latter as a way to increase your deficit if the other option – that is, lowering your calories – made your diet unsustainable.
At the end of your fat loss phase
First of all, well done on achieving the goal you set out to accomplish.
Now that you’re done dieting, you can bring your calories back up to maintenance levels.
When you do this, expect your weight to increase by a few pounds. After all the work you put into your diet, it can be scary to watch the scale go up, so keep in mind that you aren’t regaining body fat.
Your maintenance calories are higher than your deficit calories. In other words, you can eat more food to maintain your bodyweight than to lose body fat (yay!).
When you start eating more, you’ll naturally increase your carbohydrate intake, so you’ll regain some of the water and glycogen that you lost in the initial stages of the diet.
Once this process is complete, your body will settle within a range of a few pounds, which will be your maintenance range. You only need to adjust your calories if bodyweight keeps creeping up over time, which means you’re overshooting your maintenance calories.
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