Nutritionist Emma White (ANutr), MSc Human Nutrition is passionate about how food science applies to the human body, and how the nutrients in what we eat affect us and ultimately have an impact on our health.
Anyone who’s ever tried to lose weight has probably learned that progress doesn’t always move in a straight line. There’s often a point where things seem to slow down, and the exact same habits that worked well at the start don’t seem to have quite the same effect. When this happens, the number on the scales can stay the same or even increase a little, even if we’ve tried our best to stick to the plan that's got us this far.
It’s around this stage that many people come across the idea of a ‘set point weight’. Essentially, it’s the suggestion that your body has a preferred range it’s trying to keep you at, and that if you move too far away from it, your body will find ways to push back.
For some, it might seem reassuring (after all, you’ve not done anything wrong), but it can also be a bit disheartening and frustrating if we have long-term goals that seem to be out of reach. So, what does it actually mean – and how much of it is true?
What is the ‘set point’ theory?
The idea of a set point isn’t new, but it seems to be everywhere right now. You’ll see it discussed widely online, often as an explanation for why weight loss feels harder than expected, or why we sometimes regain weight that we’d already lost, without seeming to overeat.
At its simplest, the theory suggests that your body tends to maintain a certain weight range. If your weight drops below that range, your body responds as if energy is becoming scarce – by increasing hunger and reducing how much energy it uses, nudging the number on the scales back upwards (1).
As a concept, it seems to make sense, especially if you’ve experienced that feeling of getting close to a goal, only for progress to slow or stall. But as with most things in nutrition, the reality is a little more nuanced than a single theory can capture.
What the science actually shows
In order to keep you healthy, your body is constantly working to maintain balance. This includes body temperature, hydration, and energy levels – and weight regulation is part of that picture too.
This process is driven by a network of signals between your brain, gut and fat stores, many of which are influenced by hormones (2).
For example, leptin – a hormone released by fat cells – helps signal fullness. Ghrelin, produced in the gut, stimulates appetite. When you lose weight, leptin levels tend to fall while ghrelin rises. In simple terms, your body becomes a little less responsive to fullness and a little more tuned into hunger (3).
At the same time, your body may slightly reduce the amount of energy it uses. This doesn’t just apply to exercise, but also to everyday movement and basic functions. This response, sometimes called adaptive thermogenesis (4), is thought to be part of a built-in survival system. From an evolutionary perspective, conserving energy during periods of reduced food intake would have been helpful.
Genetics also play a role. Factors like body composition, appetite regulation and where you tend to store fat can all influence where your weight sits. This is one of the reasons why people with similar habits can end up at different weights.
All of this helps explain why weight loss can feel harder over time. But it’s important to be clear on one thing: while these changes can influence your progress, they don’t completely fix your weight in place.
Why weight loss often feels harder as you go
When weight loss progress slows, it’s rarely due to one single cause. More often, it’s a combination of small shifts that happen gradually and often go unnoticed.
For example, as you lose weight, your body simply needs fewer calories. A lighter body uses less energy, so the calorie intake goal that worked at the start of your weight loss journey may not have as much impact once you’ve lost a significant amount of weight.
Alongside this, everyday habits can shift. Portions might creep up slightly, you might snack a little more in between meals, or you might reduce your daily movement without realising. These are completely normal changes, but they can narrow the energy deficit that’s needed for continued weight loss.
Tracking can also become less precise over time. This might mean estimating portions more often than measuring them, skipping some days completely, or forgetting to log extras at weekends. Again, this is all very normal and entirely human, but it can make progress feel less consistent.
Then there’s appetite. As those hormonal changes come into play, you may notice you feel hungrier or think about food more often. That doesn’t mean anything has gone wrong, it’s simply your body responding to change.
Put together, these factors can create the sense that your body is fighting against you, when in reality, it’s adapting alongside your habits.
‘Set point’ or ‘settling point’?
Rather than thinking of weight as fixed at a strict ‘set point’, some research now refers to the idea of a ‘settling point’ (5).
This reflects the fact that your weight is influenced by more than biology alone. Your eating patterns, activity levels, sleep, stress and environment all play a role in where your weight stabilises over time (provided that you’re aiming for a healthy weight range for your body).
In other words, your biology isn’t deciding your weight in isolation; it’s responding to your day-to-day routine. That’s important, because it means your weight isn’t locked to one very narrow range – it can shift as your habits shift too.
What actually helps when progress slows?
When things stall, it’s easy to feel like you need to try harder or cut back on your calories further. In practice, a more measured approach tends to work better.
Start by looking at what’s changed, rather than assuming you need to eat less. A short period of more accurate tracking can often highlight where things may have drifted, whether that’s slightly larger portions, extra snacks, or higher-calorie choices at certain points in the week.
From there, small adjustments can make a real difference. This might mean weighing your portions carefully, being a bit more mindful of extras like oils or drinks, or bringing your exercise routine back to what it looked like earlier.
Building meals around protein and fibre can also make a noticeable difference. These foods tend to be more filling, which can help manage appetite as your body adapts.
It’s also worth looking at your week as a whole. Weekends often look different to weekdays, and a couple of higher-calorie days can balance out a weekday deficit without you realising.
Try to resist the urge to keep decreasing your calorie intake too. Dropping your intake very low can just exacerbate the issue of your body feeling ‘threatened’ by scarce energy. In fact, upping your intake and taking a short ‘diet break’ can be a more effective long-term solution.
Finally, don’t overlook everyday movement. Steps, general activity and time spent on your feet all contribute to your overall energy balance. If these have dipped, gently bringing them back up can help support progress.
So, what should we take away from this?
It can genuinely feel like your body is working against you when weight loss slows. But in most cases, what’s happening is simply that your body is adapting to a new set of circumstances, and a good reminder to pay close attention to your daily plan.
While biology does play a role, it doesn’t override your habits. There isn’t a fixed weight you’re stuck at, and there’s still plenty of room for change within a realistic range that’s healthy and appropriate for your body.
Weight loss is often referred to as a journey, and it may take a few different adjustments along the way, but you can still make progress even if you’ve experienced a plateau. And perhaps most importantly, this isn’t about fighting your body, it’s about understanding how it responds and working with it over time.
