Why “eat less, move more” may not always work the way we think
WHY “EAT LESS, MOVE MORE” MAY NOT ALWAYS WORK THE WAY WE THINK
This week, I was asked a question about weight loss that really made me pause.
“Are there circumstances where eating less calories than you expend does not result in weight loss?”
At first, the Energy Equation - ‘Energy In vs Energy Out’ seems simple. If you eat less than you burn, you will lose weight, and this principle still holds true.
It sounds straightforward, and in a controlled environment it may be. However, it is not always that simple, and for so many people I have met and worked with, it can be a real struggle, often leaving them feeling like they are doing everything right and still getting nowhere.
When the equation is impacted by environment
When you reduce calories, the body does not just carry on as normal. It adjusts to its environment, to the signals it is receiving, and to the state it is in. Resting metabolic rate can drop and thyroid output decline. When everything is working well, the equation tends to play out as expected. But when it is not, things can feel very different.
This is where we start to see what is often described as metabolic resistance or reduced metabolic flexibility, not because the body is broken, but because it is being protective.
This can show up in different ways. For some, it can be difficulty accessing stored energy, even when intake is reduced. For others, it is increased fat storage, particularly around the abdomen, or a sense that the body is holding on despite consistent effort.
There can be various contributing factors such as:
· thyroid function
· hormonal shifts, especially through perimenopause and menopause
· insulin resistance
· long periods of dieting
· chronic stress
· inflammation
· disrupted sleep
· or even deeper layers such as trauma and nervous system dysregulation.
None of these remove the equation, but they impact the efficiency of it, making it much harder for the body to respond.
As Andrew Huberman, a neuroscientist and professor at Stanford University, often discusses, the nervous system plays a central role in regulating energy, behaviour, and stress, and when these systems are dysregulated, it can influence everything from appetite and sleep to how the body responds to an energy deficit.
The importance of insulin sensitivity
The hormone insulin becomes an important factor in the equation.
Work from people like Ben Bikman, a researcher in metabolic health and insulin resistance, has helped bring more attention to how insulin regulates whether the body stores or releases energy. When insulin is elevated, the body is more likely to store energy and less able to access it, and as he often explains, fat loss is not just about how much energy is there, but whether the body can actually get to it.
Jason Fung, a nephrologist known for his work in fasting and metabolic health, has also spoken extensively about this, particularly the idea that obesity is influenced by hormonal signals as well as calories, and his work around fasting is largely centred on lowering insulin levels to allow the body to access stored energy more effectively.
This reflects what we see more broadly in physiology and research. It is not just how much energy is coming in, but whether the body is in a position to use it.
What is interesting is that this is also where a lot of the more recent research is heading, recognising that factors such as hormones, sleep, circadian rhythm, muscle mass, and stress all influence how the body responds to an energy deficit, and how sustainable that deficit actually is. In other words, it is not just about creating the equation on paper, but about whether the body is in a position to carry it out efficiently.
The role of muscle and protein
This is where muscle becomes central to the conversation, and something I have come to appreciate more over time, both through my own experience and through working with others.
Gabrielle Lyon, a physician and researcher focused on muscle-centric medicine, has helped shift the narrative here, particularly the idea of muscle as a key driver of metabolic health, not just something we train for strength or aesthetics.
Muscle plays a critical role in glucose disposal, in energy regulation, and in maintaining metabolic stability, and without sufficient muscle the body becomes less efficient at managing energy and less adaptable in how it uses it.
At the same time, without adequate protein, it becomes difficult to build or maintain that muscle, which is often where I see a disconnect, with people trying to reduce energy intake but not necessarily supporting the systems that allow their body to respond well to that reduction.
Leptin, environment, and energy signalling
Alongside insulin, there is increasing focus on the hormone leptin, which signals to the brain whether we have enough energy available. This is something I have come to understand more through working with Dr Ravi Gornall, a functional medicine practitioner, and listening to her speak on leptin resistance.
Leptin is often described as the body’s “energy status” signal, and when it is working well it tells the brain that there is enough energy available and the body can use it freely. But when that signalling is disrupted, the message does not land, and the brain can interpret this as a lack of available energy, even when it is not. In response, the body holds on to it rather than releasing it, almost like a state of perceived starvation.
As discussed in Dr Ravi’s work on leptin resistance, the issue is often not a lack of effort, but a disruption in how the body signals and responds to available energy.
What stood out to me is that this is not just about food. Light exposure, sleep, circadian rhythm, stress, and overall nervous system state, all influence the signals to the brain that determine whether it is safe to use energy. When these are out of sync the body tends to move into protection mode.
This is supported in a book I read recently called “The Metabolic Scam” by Dr Joshua Hackett, which challenges the idea that weight loss is simply about eating less. The argument is not that the equation is wrong, but that it is often oversimplified, because when the body is under stress, or not well supported, it adapts in ways that make accessing stored energy harder.
Where this becomes real
I have seen this play out not just in theory, but in real life.
A good friend has lived through more challenges than most people will ever face, including cancer and chemotherapy, losing her mother, and caring for a very unwell child, all layered with ongoing stress, disrupted sleep, early menopause and habits that became harder to maintain through it.
Over time, her body changed, with weight gain, poor blood sugar control, sleep apnoea, and a cycle that became increasingly difficult to break.
For the last two years, she has started to prioritise her health, continued to show up and work on the foundations (listed below), not perfectly but consistently, trusting the process and slowly unlock her equation. She is starting to see shifts, with improvements in her blood sugar control, changes in the way her body is responding, and weight beginning to move in a direction that had felt out of reach for a long time.
My own experience
My experience has not been as extreme, but for many years, I followed a low-fat, low-calorie approach, believing that eating less was the key. At the same time my protein intake was inadequate, and I had low muscle mass. I was doing many pilates classes each week, walking my 10,000 steps, but this approach was not enough to shift the last 10 kilos of post-baby weight.
I was doing the work, but not in a way that supported my body to respond, and it took me some time to realise that more effort was not the answer. I needed to eat and train differently.
I shifted my focus, towards strength training, prioritising protein, and building the foundations that support metabolic health. This was strongly influenced by the work of Gabrielle Lyon, particularly her focus on muscle as central to long-term health and how the body regulates and responds to energy.
As these pieces came together, things began to change, with improvements in body composition, energy, and the way my body responded to both training and nutrition.
The energy equation did not change, but my body’s ability to respond to it did. It is still important that I continue to make these choices, consistently over time.
Discipline still matters
It is important that the underlying factors impacting your energy equation do not become an excuse.
They can absolutely make things harder in the short term, but they do not prevent change from happening.
Understanding what might be getting in the way, and working to address it, puts you in a much better position to succeed. It still requires effort, consistency, and a level of discipline, to show up over time, commit to training, make consistent food choices and to build lifelong habits.
Returning to the foundations
What I continue to come back to, both personally and in coaching, are my foundations:
· Nutrition, including appropriate energy intake and adequate protein.
· Movement, including both strength training and some form of cardiovascular work.
· Sleep and recovery.
· Managing stress.
· Supporting circadian health through light exposure, time outdoors, and daily rhythms.
· And where appropriate, practices that support the nervous system, whether that is time in nature, grounding, sauna, or cold exposure.
These are not separate from the equation. They are the environment that determines how efficiently the equation works.
Closing reflection
We come back to the Energy Equation. It is simple, and it does work, but the experience of it is not always simple. For those in optimal health, it feels straightforward, while for others it can feel like a constant effort with little return, and this is where the nuance becomes important.
The work is not just about eating less or moving more, it is about creating an environment to support your body to respond to that effort.
· Perhaps this is where the responsibility shifts, to keep asking questions, to keep looking for what might be getting in the way of your progress, and to continue building the foundations that support your health over time.
· This is not a quick fix. It is a life habit that needs to be prioritised, a willingness to commit to change, not just for a moment, but for life.
There will be times where progress feels slow, where the return does not match the effort, and where it would be easier to step away, but it is in continuing to show up, and in continuing to refine what supports your body, that change begins to take hold, sustainably.
· The goal is not simply weight loss. It is strength, muscle, metabolic health, and the ability to move well, think clearly, and live independently for decades to come.
When you commit to that process, patiently and consistently, you are not changing the equation, you are creating lifelong habits that will determine your healthspan.
Resources
Dr. Ravi Gornall - 'Leptin and weight loss resistance' - https://youtu.be/xi5VphuzSTc?si=PT31boNgIPpNvlTD
The Metabolic Scam, How Leptin, Light and Mitochondria Shatter the Weight Loss Lie, by Joshua Hackett, MD.
