Understanding Weight & Metabolic Health Series

Hi I’m Sammy, 

Your Good Farm in-house nutritionist. Here to bring you essential information on nutrition, diet and permaculture gardening - in a bite size, easy to understand, science-backed way.

Article 1. The Mismatch Between Modern Life and Our Biology

What other topic has occupied so much of our attention as weight and diet? It's a conversation that has been around for decades, but in recent years, medications such as Ozempic have brought it into the spotlight once again, prompting new discussions about weight loss and how we approach it.

We're often told that losing weight comes down to eating less and moving more. And while energy balance is important, this explanation doesn't tell us much about why we feel hungry, why some foods are difficult to stop eating, or why two people can follow similar routines and have very different experiences with their weight.

Over the coming weeks, this series will look beyond the scales to explore weight and metabolic health. We'll look at how our food environment has changed, how dietary advice around fats and carbohydrates has evolved, and why certain diets and weight-loss trends continue to shape the way we eat. We'll also explore metabolic set point, insulin resistance, thyroid health, hormones and the role of the gut microbiome in weight regulation. And, with medications such as Ozempic changing the approach to weight management, we'll consider what these developments mean for the future.

Weight regulation is about much more than willpower. It's influenced by a complex interplay of biology, environment, nutrition and individual health. Understanding these factors can help us move beyond the familiar advice to simply eat less and move more.

When food was less predictable

Our biology developed over thousands of generations, but our food environment has changed considerably in just a few decades. In many ways, we're living in a world our biology wasn't designed for.

For much of human history, access to food was much less predictable. Availability varied with the seasons, weather, geography and the success of hunting, gathering and, later, farming. Many populations experienced periods when food was scarce or difficult to obtain.

Our ancestors didn't all eat the same way, and there was no single ancestral diet. Traditional populations have consumed vastly different dietary patterns depending on their environment, from animal-food-rich diets in Arctic regions to diets rich in tubers, berries, fruit and wild game among hunter-gatherer populations such as the Hadza in Tanzania.

Looking at the dietary patterns and health of traditional populations can offer useful insights into the relationship between food, lifestyle and metabolic health. Many of these populations have historically experienced lower rates of some chronic metabolic diseases that are common in modern industrialised societies, although diet is only one part of the picture.

The ability to seek out food, respond to hunger and store energy for later use was valuable in these environments. Body fat is not a flaw. It's an energy reserve, and our bodies have several mechanisms designed to protect it. But body fat is more than just stored energy. It's metabolically active tissue that communicates with the brain and other organs, helping regulate appetite, hormones, inflammation and energy balance. Where we store fat is also important. Excess fat stored around internal organs, for example, is associated with greater metabolic risk and insulin resistance.

When energy intake falls, the body can respond by increasing hunger and reducing energy expenditure. These responses helped people navigate periods of scarcity. They can also make sustained weight loss difficult in the modern world.

Periods of feast and famine have also shaped how we think about eating patterns today. Across history, different cultures have incorporated periods without food into their traditions, particularly for religious and spiritual reasons. More recently, researchers have explored whether planned periods of fasting may offer benefits for metabolic health and weight management, which we'll explore later in this series.

The modern food environment

For many of us, food is available around the clock. We can buy a meal, order takeaway or reach for a snack without much effort. We're surrounded by opportunities to eat, whether we're hungry or not.

Think about a typical Australian supermarket. Whole foods, or foods closest to their natural state, tend to sit around the outer edges, while the centre aisles are filled with thousands of packaged products designed to be convenient and hard to resist. Clever packaging and health claims can make it difficult to distinguish genuinely nourishing foods from products that simply appear healthy.

There's an irony here. Many supermarkets have a dedicated aisle labelled "health foods", as though health were a special category rather than something we should consider across the entire store.

Imagine if we labelled the aisles differently. Would we have one for "ultra-processed foods"? Or even "inflammatory foods"?

Food writer Michael Pollan has made an interesting observation about this. He describes some of the healthiest foods as the quietest. Broccoli doesn't need to make a health claim. It simply sits there, quietly being broccoli. Meanwhile, as you move into the middle aisles, products are practically screaming at you: "lite", "low fat", "high fibre" and "high protein". Almost everything seems to be selling you a reason why it's good for you. It can get noisy and confusing, and that's just in the supermarket aisle. The same conflicting messages follow us into conversations about health and dietary advice.

But there's more to this than clever marketing. Many ultra-processed foods are formulated to be highly palatable, combining ingredients such as refined carbohydrates, fats, salt and flavourings in ways that can encourage us to eat more.

Our brains are wired to respond to rewarding foods. Some products are also designed with textures and flavours that require little chewing and can be consumed quickly, potentially outpacing the signals from our gut and brain that help regulate appetite and fullness.

The food industry invests considerable resources into understanding consumer preferences, flavour, texture and product development. The result is an environment filled with convenient foods that are designed to appeal to us and encourage repeat consumption.

So, if we remove processed and packaged foods from our diets, is weight loss easier?

Moving towards whole, minimally processed foods is an excellent starting point. These foods generally provide more fibre and nutrients, helping support satiety, metabolic and overall health.

But eating well doesn't automatically mean weight loss will follow. Someone can eat a diet rich in whole foods, vegetables and complex carbohydrates, yet still struggle with hunger, frequent snacking or weight management.  The right balance of protein, fats and carbohydrates, overall energy intake and individual metabolic health can all play a role.

I can speak from personal experience. I had a complicated relationship with food and my body from my teens, which continued into my mid-twenties. It wasn't until I began studying human nutrition that things started to come together more easily.

At the time, everything I ate would have been considered whole food, but the balance of macronutrients in my diet was out. I was constantly hungry, snacking throughout the day and stumped as to why, despite eating what I thought was a healthy diet, I wasn't seeing the changes I expected.

We'll explore different whole-food dietary approaches, how they compare and what the research tells us about their effects on weight and metabolic health later in this series.

We're eating differently, and often doing more while eating

It's not just what we eat. It's also how we eat.

Meals are increasingly squeezed between work, school runs, appointments and other commitments. We eat at our desks, in the car or in front of a screen. Eating can become something we do alongside other activities rather than something we give our attention to.

When we eat quickly or while distracted, it can be harder to notice when we've had enough. We may finish a meal before we've registered how satisfied we feel, gradually losing touch with the body's natural feedback signals around hunger and fullness.

The other pieces of the puzzle

Sleep and stress can have a significant impact on appetite, food preferences and eating patterns. Poor sleep, for example, can increase hunger and influence the types of foods we're drawn to, while chronic stress can affect how and when we eat.

Access to nourishing food, time to cook, income, medications, health conditions and life circumstances also shape what's realistic for each person.

Our gut microbiome may be another piece of the picture. The trillions of microorganisms living in our digestive tract interact with the foods we eat and can influence digestion, gut hormone signalling, inflammation and metabolic health. Researchers are still working to understand exactly how these interactions affect body weight, but it's an increasingly interesting area of research.

Taken together, these factors remind us that weight is influenced by much more than what's on our plate. It's a combination of biology, environment, lifestyle and individual circumstances.

In Summary

Understanding evolutionary mismatch gives us another way to look at weight and metabolic health. Rather than focusing solely on calories, diet or exercise, it encourages us to consider how our modern environment interacts with our biology.

In the next article, we'll look at how nutrition advice has changed over the years, from the low-fat era to today's debates about carbohydrates, protein and dietary fats, and what the research tells us about the most sustainable approach to weight loss.

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A note to readers

These articles are intended as a guide to understanding weight and metabolic health, not as a substitute for individual health advice or clinical consultation.

We recognise that conversations around weight and body image can be incredibly triggering, particularly if you're not where you'd like to be with your health or body goals. Please take what is useful to you and leave what isn't.

If you're looking for individual support, consider working with an experienced naturopath or nutritionist who takes a similar holistic approach and has the appropriate clinical experience to provide personalised care.

We'd love to hear from you. If you have any feedback, questions or topics you'd like us to explore further, please leave a comment below.

References

Andrews, P. & Johnson, R.J. (2020). Evolutionary basis for the human diet: consequences for human health. Journal of Internal Medicine.

Fan, Y. & Pedersen, O. (2021). Gut microbiota in human metabolic health and disease. Nature Reviews Microbiology.

Hall, K.D., et al. (2019). Ultra-Processed Diets Cause Excess Calorie Intake and Weight Gain: An Inpatient Randomized Controlled Trial of Ad Libitum Food Intake. Cell Metabolism.

Lane, M.M., et al. (2024). Ultra-processed food exposure and adverse health outcomes: umbrella review of epidemiological meta-analyses. BMJ.

Pontzer, H. (2015). Constrained Total Energy Expenditure and the Evolutionary Biology of Energy Balance. Exercise and Sport Sciences Reviews.

Scheja, L. & Heeren, J. (2019). The endocrine function of adipose tissues in health and cardiometabolic disease. Nature Reviews Endocrinology.

St-Onge, M-P., et al. (2016). Sleep Duration and Quality: Impact on Lifestyle Behaviors and Cardiometabolic Health. Circulation.