The fitness world is full of simplified adages meant to portray foundational concepts. One of these is to “Eat Less, Move More” when you want to lose weight.
Once a foundational concept, this simple piece of advice has been questioned recently, with many claiming that it doesn’t work anymore; what happened?
Actually nothing. This article will break down this argument and demonstrate that “eating less and moving more” is still the heart of weight loss and general fitness.
Key Points You Need To Know!
“Eat less, move more” summarizes the basic concept of weight loss. “Eat less” refers to eating fewer calories; “move more” refers to increasing energy expenditure.
It is not meant to be, nor does it claim to be, an all-encompassing guide to losing weight.
Most importantly, it works.
What Does “Eat Less, Move More” Mean?
Energy balance is considered the primary driver of weight gain and loss. This can be influenced through two main factors:
Energy Intake (Calories Consumed)
Energy Expended (Calories “Burned”)
In order to lose weight, you need to be in a caloric deficit, meaning you burn more calories than you eat. Therefore, “Eat Less, Move More” means exactly how it sounds.
While simplistic, it’s ultimately just encouraging people to attack weight loss from both angles.
For example, if you wanted to get in a 500-calorie deficit, you could;
Eat 500 fewer calories.
Burn 500 more calories.
Eat 250 fewer calories + burn 250 calories
Does “Eat Less, Move More” Work?
Yes.
It’s important to note that these 4 words were never meant to be all-encompassing guidelines, any more than “eat more vegetables” is meant to be a full diet plan.
Both parts of this strategy should be broken down further to address various factors. Further, an individual having difficulties should speak to a professional to help assess the hurdles they face.
However, any strategy used will ultimately lead back to” Eat less, move more”. Always. Even medical interventions, such as GLP-1 or Bariatric surgery, aim to help a person eat less.
Yet if you Google “eat less, move more,” you will find numerous articles that say it doesn’t. We’re talking about articles like;
1. EatingWell: Why “Eat Less, Move More” Doesn’t Actually Work for Weight Loss, According to Dietitians
2. Black Rock Weight Care: Why “Eat Less and Move More“ Just Doesn’t Work for Obesity
3. The Conversation; “Obesity care: why ‘eat less, move more‘ advice is failing.”
4. Lifestyle Inquirer; “When ‘eat less, move more‘ stops working in midlife.”
5. Dr. Jolene Brighten; “Why Eat Less and Exercise More is Bad Advice for Women.”
These were not hard to find, as this messaging has become mainstream. So what gives?
Dangerous Messaging
We could theorize what’s pushing this agenda.
Selling supplements or procedures
Part of the body positivity movement
We could also point to obvious examples of data manipulation to support these claims. But we won’t.
However, we can confidently say this is dangerous messaging. Making any dramatic life changes can be difficult.
Stop smoking
Getting over the fear of the dentist
Saving money
Any type of addiction, even an unhealthy addiction to exercise
But just because something is hard, it doesn’t mean it’s not important. In many cases, the harder something is, the more important it is!
Speaking about this exact issue in 2015, Blundell et al (2015) stated:
“Because many people are pleased to read messages about the futility of exercise to reinforce a preference to avoid PA, the implication of this publicity is serious.”
They follow up by saying;
“Importantly, these messages portrayed in the popular media are false. There is clear evidence from large-scale controlled trials that PA (physical activity) carried out over long periods of time produces a dose-dependent reduction in body weight.”
Why “Eating Less” Doesn’t Work (Supposedly)
A lot of pushback against “Eat Less, Move More“ centers on “eating less.“ In a nutshell, it gives several reasons why eating less doesn’t lead to fat loss.
Many arguments claim that “Eat less, move more“ denies the role of other factors in fat loss. This is false.
In fact, you’ll notice we have addressed all of these issues in the past.
Regardless, explaining the complexity and internal mechanisms of fat loss doesn’t override basic advice.
With that said, here are some of the key arguments.
Hormones and the Endocrine System Determine Fat Loss
It is true that hormones play a role in fat loss, and this can be more pronounced in some people. However, it is rarely, if ever, the primary driver of fat loss.
This would be like saying resistance training and eating protein don’t actually build muscle because some men have low testosterone. Low testosterone can definitely affect muscle growth, but this is a dysfunction, not normal body function.
Some of the primary endocrine issues that can legitimately make weight loss difficult are:
Cushing’s Syndrome- 40-70 people per million / 0.01% of the population
Severe (Overt) Hypothyroidism- 0.3-2% of the population (Patil et al., 2024)
Leptin Deficiency- <0.01% of the population
However, these affect a very small portion of the population.
There are also other conditions that can make losing weight harder, but they don’t override energy balance.
Hypothyroidism is a common example, but research shows a meaningful effect on energy expenditure is generally only seen in severe cases. Still, research shows the actual effect can vary greatly, sometimes being non-existent (Harsini et al., 2024).
PCOS is another condition that affects women, resulting in insulin resistance. However, insulin resistance does not override energy balance, and a true caloric deficit will still result in weight loss.
Further, A large preprint (currently under peer review) meta-analysis of 13 studies found that resting energy expenditure differed by only ~30 kcal/day between women with and without PCOS (Kirwan et al., 2026).
However, “eat less, move more“ may not work as PCOS influences appetite, activity levels, and metabolic responses. This makes achieving and sustaining that deficit more difficult due to behavioral challenges rather than physiology.
When other hormones are mentioned, extreme examples of calorie restriction are often used to support their argument.
A common study to demonstrate that calorie restriction increases cortisol used subjects on a 1,200-cal/day diet (Tomiyama et al., 2010).
To “prove“ dysregulation of the thyroid, a study that used participants on a 400-cal/day diet was cited (Wadden et al., 1990).
A study that had women on a 330cal/day diet is used to prove calorie restriction lowers testosterone (Kiddy et al. 1989)
All Calories Aren’t The Same
This claim is repeated so often that it deserves its own conversation! That’s why we have written our own stand-alone article!
The argument basically says that different foods with the same caloric value can have different effects on your body.
Some foods increase satiety more (this is why we encourage protein!)
Different carb sources can affect insulin differently.
Whole foods offer greater nutritional value.
And they’re right!
But this has nothing to do with the calories. A “calorie“ is simply a unit of measurement for energy, and energy is energy.
Therefore, it doesn’t make sense to say a calorie from chocolate cake is different from the calories in chicken.
What’s different is;
The chicken provides protein, which increases satiety and supports muscle mass.
The cake contains added sugar and salt, which will add calories and possibly increase appetite, while providing 0 nutritional value.
Therefore, it’s nutrients and compounds within food that affect your body differently; calories are just innocent bystanders. However, framing it as “calories“ misleads people from understanding that a calorie is just a measurement of the energy the body requires.
Metabolic Adaption
Metabolic adaptation is when a person’s metabolism can be lowered during prolonged periods of calorie restriction. It’s theorized that this is your body’s attempt at preserving energy.
Now, there is some truth here, and it is an interesting component of weight loss. This is observed in several studies, and we have actually written an article on it (Byrne et al., 2018).
However, this doesn’t mean weight loss comes to a halt.
Further, there are methods to mitigate this, such as intermittent calorie restriction. This is the practice of alternating between periods of calorie restriction and calorie maintenance.
For example;
3 weeks of a 500-calorie deficit daily
1 week of maintenance
Byrne et al (2018) found that taking diet “breaks“ can result in greater fat loss and have a lower effect on the metabolism. But there are two important takeaways:
“Eat less“ is still the mechanism of fat loss.
Consistent groups still lose weight.
Why “Moving More” Doesn’t Work
Believe it or not, suggesting exercise is an effective tool for weight loss has even been criticized. This one is a bit confusing, as many of the arguments are self-defeating.
One overarching fallacy is that these arguments frame calorie expenditure as the primary reason you train.
We believe the primary reason you should train is the plethora of health benefits, while the burned calories are the “cherry on top.”
Still, while “10,000 steps“ might sound cliche, finding someone who follows this rule and hasn’t lost weight is challenging.
We’ll address some specific claims below, but keep in mind that exercise has consistently been found to be an effective tool for weight loss, both in the short term and for long-term adherence.
Exercise alone can be superior to diet alone (Clark, 2015).
Exercise + Diet is superior to Diet alone for weight loss (Clark, 2015; Wu et al., 2009).
Exercise + Diet is superior to Diet alone for long-term adherence (Wu et al., 2009)
Energy Compensation Theory / Constrained Energy Model
The energy compensation theory is basically the exercise version of metabolic adaptation.
It suggests that when a person exercises or increases activity, the body compensates by lowering caloric expenditure elsewhere, e.g., by lowering BMR while you sleep.
Again, this is a highly nuanced topic, but we wrote a full article about the constrained energy model here. Here are some key points from that article.
1. Outlets that promote the constrained model use studies that show this may occur during high levels of activity. Generally, it’s only seen in the highest 30% of activity levels, not in sedentary people.
In other words, it’s not a concern for the vast majority of people, especially the ones who need movement the most.
2. When this does occur, studies show a drop of 20-30% maximum, not full compensation.
3. In the largest and most extreme example, ultra-marathon runners ran 250 km/week (155 miles) for 20 weeks; that’s around 6 marathons a week for 4-5 months.
Even here, there was only a 20-25% adaptation in energy expenditure. Further, this seems to have been an acute change rather than a long-term adaptation.
4. This doesn’t seem to occur with resistance training, only prolonged cardio, but this is never mentioned.
Exercise Can Reduce Activity Levels
Some argue that exercise can ultimately lead people to move less during the day.
To be clear, they are separating exercise and general physical activity, such as walking your dog or taking the stairs.
However, “move more” doesn’t mean running miles; it means to increase activity levels. So they are arguing the concept of “move more“ by showing the importance of “move more”.
This is another example where it seems they want to loudly tear down the notion of exercise and dieting by quietly using the same concepts.
The irony is that they have to because of how weight loss occurs; you will never see them produce an example of weight loss through any other means, nor explain how this simple concept has worked, and is working, for millions of people.
That said, while this can occur to some extent, it rarely offsets the calories burned during exercise. It’s generally seen with;
Prolonged cardio or extended intense training
New trainees, as the training may result in sore muscles.
Short-term exercise interventions, as the body adapts
However, long-term exercise tends to have no effect on physical activity or may even increase it. In fact, a large review clearly states this.
“Resistance exercise and a prolonged exercise engagement… may actually increase habitual PA (physical activity) as a result of increased fitness and functional capacity.“ (Drenowitz, 2015).
Exercise Makes You Hungry
The claim is that exercise doesn’t always work because exercise increases appetite. This causes them to eat more, which cancels out the calories they burned.
This is not only over-simplified, but it’s also incomplete.
Increased appetite as compensation for energy expenditure tends to be a stronger mechanism within lean individuals. This is likely due to a built-in survival mechanism trying to preserve mass. (Durrant et al., 1982; Drenowatz, 2015).
When compensation does occur, it tends to be partial. In other words, you don’t “eat all your calories back”.
Similar to the claim on activity levels, compensation tends to occur at the beginning of a training intervention. Compensation tends to be absent or minimal after an intervention > 3 weeks. Further, long-term adherence can actually reduce appetite and increase control of fasting hunger (Blundell et al., 2015).
The Elephant In The Room
Selling products and making money doesn’t automatically make a message untrue. Heck, we hope you check out our programs and supplements!
However, it’s also hard to ignore when it’s a running theme.
You will notice that a lot of the articles and individuals who promote the idea that traditional weight loss doesn’t work are linked to a weight-loss product of some sort.
This is related to the overall problem because when people are constantly being told these powerful behavior modifications, how else are they supposed to be able to lose weight? This isn’t meant to discourage or criticize anyone using these interventions, but rather the messaging, as it illustrates the overall issue of overcomplicating weight loss.
Final Say: Does “Eat Less, Move More“ Work?
Study of the body’s metabolic systems and energetics is interesting as much as it is complicated. But lucky for us, the complex mechanisms don’t require much from us anymore than the systems that control walking; we just walk.
Everyone’s body is different, and dieting will present more or less challenges, but the primary mechanism remains the same. Further, when individuals do face medical conditions, these should be discussed within context and focused rather than blanket statements and general prescriptions.
The bottom line is that “Eat less, move more“ works. Differences in our physiologies will just dictate if and how challenging it is.
References
Blundell, J. E., Gibbons, C., Caudwell, P., Finlayson, G., & Hopkins, M. (2015). Appetite control and energy balance: impact of exercise. Obesity reviews : an official journal of the International Association for the Study of Obesity, 16 Suppl 1, 67–76. https://doi.org/10.1111/obr.12257
Byrne, N. M., Sainsbury, A., King, N. A., Hills, A. P., & Wood, R. E. (2018). Intermittent energy restriction improves weight loss efficiency in obese men: The MATADOR study. International Journal of Obesity, 42(1), 129–138. https://doi.org/10.1038/ijo.2017.206
Careau, et al. (2021). Energy compensation and adiposity in humans. Current biology : CB, 31(20), 4659–4666.e2. https://doi.org/10.1016/j.cub.2021.08.016
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Harsini, A. R., et al. (2024). Are resting metabolic rate and clinical symptoms affected by thyroid-stimulating hormone levels within the reference range? Clinical Nutrition ESPEN. https://www.sciencedirect.com/science/article/abs/pii/S2405457724000603
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Kirwan, R., Peele, L., Nuckols, G., Kohlhoff, G., Cabré, H., Olenick, A., & Steele, J. (2026). Resting energy expenditure of women with and without polycystic ovary syndrome: a systematic review and meta-analysis. medRxiv : the preprint server for health sciences, 2025.12.03.25341536. https://doi.org/10.64898/2025.12.03.25341536
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