The Times Australia
The Times World News

.
The Times Real Estate

.

It's time to bust the 'calories in, calories out' weight-loss myth

  • Written by Nick Fuller, Charles Perkins Centre Research Program Leader, University of Sydney
It's time to bust the 'calories in, calories out' weight-loss myth

If you’ve ever tried to lose weight, there’s a good chance you’ve been told it all comes down to a simple “calories in, calories out” formula: burn more calories than you consume, and the kilos will disappear.

And it’s easy to see the appeal of breaking weight loss down into simple maths – just follow the formula, and you’ll achieve success. It’s also believable because many people do lose weight when they first adopt this approach.

Indeed, the diet industry’s reliance on the “calories in, calories out” concept is why society blames people for being overweight. Anyone who can’t follow this simple energy formula is only overweight because they lack the willpower to eat less and exercise more.

But the only simple truth here is that it’s time to bust the “calories in, calories out” myth as the only way to lose weight. Here’s why.

Read more: Does exercise help you lose weight?[1]

It’s nearly impossible to calculate accurately

The many calorie-counting apps and online calculators available make it seem effortless. Simply enter your sex, age, height, weight, body composition and activity levels and they’ll tell you exactly how many calories you should eat daily to lose weight.

Unfortunately, no matter how accurate these calculators claim to be, they rely on averages and can’t determine the calorie intake appropriate for you with 100% accuracy. They can only estimate.

Similarly, our metabolic rate – how much energy we burn at rest – also varies from person to person based on many factors, including body composition or how much muscle and fat we have. Complicating things further, our metabolic rate also alters when we change our diet and lose weight.

Brunch table with lots of food
Our metabolic rate varies from person to person. Unsplash/Ali Inay[2]

Calculating the calories in food – the other part of managing “calories in” – is also far from accurate.

While Australian food standards require foodstuffs to display Nutrition Information Panels showing energy in kilojoules, there are no requirements for information accuracy other than it must not be misleading. A worrying +/-20% discrepancy is generally accepted[3] for the values shown on labels.

In practice, the variation can be much more than this. One Australian study found food contained anywhere between 13% less and 61% more[4] energy or nutrient components than its packaging stated.

Not all calories are created, or consumed, equally

Another reason the simple “calories in, calories out” formula is not so simple is our bodies don’t consume every calorie the same way. What’s shown in your calorie counter is not what’s actually absorbed in your body.

Different calorie sources also have different effects on our hormones, brain response and energy expenditure, changing how we respond to and manage our food intake.

Read more: The last 5 kilos really are the hardest to lose. Here’s why, and what you can do about it[5]

For example, while eating 180 calories worth of nuts is the same as eating 180 calories of pizza in terms of energy intake, the way these foods are absorbed and how they affect the body is very different.

While we absorb most of the calories in a slice of pizza, we don’t absorb about 20% of the calories[6] in nuts because their fat is stored in the nut’s fibrous cell walls, which don’t break down during digestion. Nuts are also packed with fibre filling us up for longer, while a slice of pizza has us immediately reaching for another due to its low fibre content.

Our bodies disrupt the formula

The biggest failing of the “calories in, calories out” formula is it ignores that the body adjusts its control systems when calorie intake is reduced. So while the formula can support people achieving weight loss initially, the reduction in energy intake is counteracted by mechanisms[7] that ensure lost weight is regained.

Namely, when your body registers a sustained decrease in the calories you consume, it believes its survival is threatened. So it automatically triggers a series of physiological responses[8] to protect against the threat, reducing our metabolic rate and burning less energy.

This stems from our hunter-gatherer ancestors, whose bodies developed this response to adapt to periods of deprivation when food was scarce to protect against starvation.

Dance class
Our body slows our metabolism in response to weight loss. Unsplash/Danielle Cerullo[9]

Research also suggests our bodies have a “set point weight[10]”: a genetically predetermined weight[11] our bodies try to maintain regardless of what we eat or how much we exercise.

Our bodies protect our set point as we lose weight, managing biological signals from the brain and hormones to hold onto fat stores in preparation for future reductions in our calorie intake.

Read more: What's the 'weight set point', and why does it make it so hard to keep weight off?[12]

The body achieves this in several ways, all of which directly influence the “calories in, calories out” equation, including:

Greasy pizza
Eating 180 calories worth of nuts is not the same as eating 180 calories of pizza in terms of energy intake. Unsplash/Alan Hardman[19]

Our bodies also cleverly trigger responses aimed at increasing our calorie intake to regain lost weight, including:

  • adjusting our appetite hormones. When we reduce our calorie intake and deprive our bodies of food, our hormones work differently, suppressing feelings of fullness[20] and telling us to eat more

  • changing how our brain functions. When our calorie intake reduces, activity in our hypothalamus – the part of the brain that regulates emotions and food intake – also reduces, decreasing our control[21] and judgement over our food choices.

Bottom line

The “calories in, calories out” formula for weight loss success is a myth because it oversimplifies the complex process of calculating energy intake and expenditure. More importantly, it fails to consider the mechanisms our bodies trigger to counteract a reduction in energy intake.

So while you may achieve short-term weight loss following the formula, you’ll likely regain it.

What’s more, calorie counting can do more harm than good, taking the pleasure out of eating and contributing to developing an unhealthy relationship with food. That can make it even harder to achieve and maintain a healthy weight.

For long term weight loss, it’s important to follow evidence-based programs from health-care professionals and make gradual changes to your lifestyle to ensure you form habits that last a lifetime.

Read more: Is menopause making me put on weight? No, but it's complicated[22]

At the Boden Group, Charles Perkins Centre, we are studying the science of obesity and running clinical trials for weight loss. You can register for free here[23] to express your interest.

References

  1. ^ Does exercise help you lose weight? (theconversation.com)
  2. ^ Unsplash/Ali Inay (unsplash.com)
  3. ^ +/-20% discrepancy is generally accepted (pubmed.ncbi.nlm.nih.gov)
  4. ^ between 13% less and 61% more (pubmed.ncbi.nlm.nih.gov)
  5. ^ The last 5 kilos really are the hardest to lose. Here’s why, and what you can do about it (theconversation.com)
  6. ^ 20% of the calories (academic.oup.com)
  7. ^ counteracted by mechanisms (www.ncbi.nlm.nih.gov)
  8. ^ triggers a series of physiological responses (pubmed.ncbi.nlm.nih.gov)
  9. ^ Unsplash/Danielle Cerullo (unsplash.com)
  10. ^ set point weight (theconversation.com)
  11. ^ genetically predetermined weight (www.ncbi.nlm.nih.gov)
  12. ^ What's the 'weight set point', and why does it make it so hard to keep weight off? (theconversation.com)
  13. ^ further 15% decrease in metabolism (pubmed.ncbi.nlm.nih.gov)
  14. ^ doesn’t recover (pubmed.ncbi.nlm.nih.gov)
  15. ^ fewer hormones are secreted (pubmed.ncbi.nlm.nih.gov)
  16. ^ switches from using fat as its energy source (pubmed.ncbi.nlm.nih.gov)
  17. ^ resulting in less energy being burned (pubmed.ncbi.nlm.nih.gov)
  18. ^ changes how our bodies process, store and burn fat (pubmed.ncbi.nlm.nih.gov)
  19. ^ Unsplash/Alan Hardman (unsplash.com)
  20. ^ suppressing feelings of fullness (pubmed.ncbi.nlm.nih.gov)
  21. ^ decreasing our control (pubmed.ncbi.nlm.nih.gov)
  22. ^ Is menopause making me put on weight? No, but it's complicated (theconversation.com)
  23. ^ here (redcap.sydney.edu.au)

Read more https://theconversation.com/its-time-to-bust-the-calories-in-calories-out-weight-loss-myth-199092

The Times Features

Understanding the Dangers of Ignoring a Gas Leak

Gas leaks are silent threats lurking within both homes and workplaces. A gas leak occurs when natural gas or any other gaseous substance escapes from a pipeline or containment. T...

Can You Sell Your House Privately in Queensland? Here’s How

Selling a house privately in Queensland is entirely possible and can be a cost-effective alternative to using a real estate agent. While agents provide valuable expertise, their co...

Itinerary to Maximize Your Two-Week Adventure in Vietnam and Cambodia

Two weeks may not seem like much, but it’s just the right time for travelers to explore the best of Vietnam and Cambodia. From the bustling streets of Hanoi to the magnificent te...

How to Protect Your Garden Trees from Wind Damage in Australia

In Australia's expansive landscape, garden trees hold noteworthy significance. They not only enhance the aesthetic appeal of our homes but also play an integral role in the local...

Brisbane Homeowners Warned: Non-Compliant Flexible Hoses Pose High Flood Risk

As a homeowner in Brisbane, when you think of the potential for flood damage to your home, you probably think of weather events. But you should know that there may be a tickin...

Argan Oil-Infused Moroccanoil Shampoo: Nourish and Revitalize Your Hair

Are you ready to transform your hair from dull and lifeless to vibrant and full of life? Look no further than the luxurious embrace of Argan Oil-Infused Moroccanoil Shampoo! In a...

Times Magazine

"Eternal Nurture" by Cara Barilla: A Timeless Collection of Wisdom and Healing

Renowned Sydney-born author and educator Cara Barilla has released her latest book, Eternal Nurture, a profound collection of inspirational quotes designed to support mindfulness, emotional healing, and personal growth. With a deep commitment to ...

How AI-Driven SEO Enhancements Can Improve Headless CMS Content Visibility

Whereas SEO (search engine optimization) is critical in the digital landscape for making connections to content, much of it is still done manually keyword research, metatags, final tweaks at publication requiring a human element that takes extensiv...

Crypto Expert John Fenga Reveals How Blockchain is Revolutionising Charity

One of the most persistent challenges in the charity sector is trust. Donors often wonder whether their contributions are being used effectively or if overhead costs consume a significant portion. Traditional fundraising methods can be opaque, with...

Navigating Parenting Arrangements in Australia: A Legal Guide for Parents

Understanding Parenting Arrangements in Australia. Child custody disputes are often one of the most emotionally charged aspects of separation or divorce. Parents naturally want what is best for their children, but the legal process of determining ...

Blocky Adventures: A Minecraft Movie Celebration for Your Wrist

The Minecraft movie is almost here—and it’s time to get excited! With the film set to hit theaters on April 4, 2025, fans have a brand-new reason to celebrate. To honor the upcoming blockbuster, watchfaces.co has released a special Minecraft-inspir...

The Ultimate Guide to Apple Watch Faces & Trending Wallpapers

In today’s digital world, personalization is everything. Your smartwatch isn’t just a timepiece—it’s an extension of your style. Thanks to innovative third-party developers, customizing your Apple Watch has reached new heights with stunning designs...

LayBy Shopping