How Carbohydrates Changed: From Traditional Foods to Modern Staples

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.

Let's talk about carbohydrates!!

Carbohydrates have been part of the human diet for thousands of years, but the way we grow, process and consume them has changed dramatically.

Traditionally, foods such as roots, tubers, fruits, legumes and grains were eaten in whole, seasonal, and carefully prepared forms that preserved their structure and moderated digestion. These foods provided energy alongside fibre, micronutrients and protective plant compounds, supporting satiety, gut health and steady energy levels. Today, carbohydrates are more commonly consumed as refined, fast-digesting products that behave very differently in the body, making it important to understand this shift when deciding how much carbohydrate to eat or which types best support health.

Traditional Processing: Structure Matters

In earlier food cultures, grains were stone-ground or hand-milled to retain the bran and germ. Legumes and grains were soaked, sprouted, or fermented to improve mineral absorption, and root vegetables were cooked slowly, often with fats, helping to moderate their effect on blood sugar.

These practices preserved fibre and larger particle size, slowing starch breakdown and supporting steady energy release. Carbohydrates were eaten as part of balanced meals rather than in isolation, contributing to satiety, stable blood glucose and a diverse gut microbiome.

Modern industrial processing has fundamentally altered this relationship. Roller milling removes the bran and germ, leaving refined starch. Ultra-fine grinding, extrusion and instantization accelerate digestion and reduce fibre content. Although vitamins and minerals may be added back through fortification, the original food structure is lost, changing how the food behaves in the body.

Highly refined carbohydrates also alter different aspects of the gut environment by reducing microbial diversity and short-chain fatty acid production, increasing inflammatory signalling and weakening the intestinal barrier over time. This helps explain why many modern carbohydrate foods are harder to tolerate. The issue may not be the carbohydrate itself, but the way it is processed and manufactured that lies at the heart of the dilemma.

Modern Plant Foods: Altered Over Time

Processing is only part of the story. Over time, fruits, vegetables and grains have also been selectively bred for sweetness, size, yield and shelf life. While this has improved availability, it has altered nutrient balance.

Many modern varieties contain higher levels of sugar or starch relative to fibre, protein and protective compounds than their heirloom counterparts. Corn illustrates this clearly: traditional varieties were much smaller and more fibrous, whereas modern corn is sweeter and more carbohydrate dense. Similar patterns are seen across other fruits and vegetables.

This does not mean plant foods are unhealthy, but it does mean even whole foods exist on a spectrum. Variety, preparation and portion size now play a larger role in how these foods affect the body.

Where Dietary Guidelines Fit and Where They Fall Short

Australian Dietary Guidelines place carbohydrate-rich foods, particularly grains, at the foundation of the recommended eating pattern. The plate or pie chart reinforces this, allocating one of the largest shares of daily intake to grain foods, with comparatively less emphasis on protein and fats.

While wholegrains have their place, the guidelines make little distinction between intact, minimally processed carbohydrates and highly refined grain products. Foods such as breakfast cereals, breads, crumpets and crackers are therefore widely promoted as healthy staples, despite being highly processed, rapidly digested and poorly supportive of blood glucose regulation and overall health.

These recommendations were shaped by older observational nutrition studies, which underestimated the role of refined carbohydrates and 

ultra-processed foods in insulin resistance, inflammation, and metabolic disease, focusing instead almost exclusively on saturated fats as the culprit. Agricultural priorities and food manufacturing practices further reinforced grain-based foods as dietary cornerstones.

The real-world outcome is evident in institutional settings, including hospitals and schools, where guideline-compliant meals often centre on processed cereals and low-fat dairy. These meals meet recommendations on paper but provide limited nourishment, leaving many people hungry, fatigued and metabolically stressed rather than supported.

Current evidence shows that metabolic health depends far more on food quality, structure and processing than on carbohydrate quantity alone. When refined grain foods dominate the diet, even under the banner of “wholegrains,” they contribute to the chronic conditions now considered lifestyle diseases.

Setting the Foundation

Carbohydrates have not suddenly become harmful. The way they are grown, processed and consumed has changed.

Understanding this context allows carbohydrates to be assessed more clearly and used more intentionally. In Part 2 of Understanding Carbohydrates, we will explore the different types of carbohydrates: sugars, starches, and fibre, and how they affect the body in distinct ways, so you know how to structure meals around them.

If you missed the fat and protein series you can look back over the latest blogs and catch up. 

Thanks for reading,

Love Sammy x