The concept of the calorie, as we understand it today, has its roots in the industrial revolution. In the 19th century, scientists studying steam engines sought to measure the energy required to fuel machines. Eventually, this same metric was applied to human nutrition, giving rise to the calorie as a measure of energy in food. The simplicity of this equation—calories in versus calories out—has dominated dietary guidelines for decades. However, this approach overlooks the intricate workings of the human body, particularly the role of hormones and metabolic processes in determining how we utilise food.
The calorie-counting philosophy assumes that all calories are created equal, regardless of their source. This is fundamentally flawed. Different foods have vastly different effects on our bodies due to the endocrine (hormonal) responses they trigger. For instance, carbohydrates, particularly refined ones, cause a rapid spike in blood sugar levels, prompting the release of insulin. Insulin—a key hormone in metabolism—helps regulate blood sugar but also signals the body to store fat. Over time, excessive carbohydrate consumption can lead to insulin resistance, a precursor to type 2 diabetes and a host of other health issues.
Cortisol, the body’s stress hormone, also plays a significant role in metabolism. Chronic stress and high cortisol levels can promote fat storage, particularly in the abdominal area, and disrupt overall hormonal balance. This underscores why it’s not just about the number of calories consumed but how these calories interact with your body’s hormonal systems.
The conventional advice to follow a high-carb, low-fat diet has compounded these issues. While well-intentioned, this guidance often leads to overconsumption of processed carbohydrates and insufficient intake of healthy fats and proteins. Healthy fats—from sources like avocados, nuts, and olive oil—are crucial for hormone production and overall cellular health. Similarly, adequate protein intake supports muscle maintenance, satiety, and metabolic function.
A more balanced approach prioritises lower-carbohydrate, high-fibre plant foods, alongside optimal protein and healthy fats. Fibre slows digestion, stabilises blood sugar levels, and supports gut health, all of which are vital for metabolic well-being. By focusing on the quality and metabolic impact of foods, rather than simply tallying calories, we can create diets that align with our body’s natural rhythms and promote sustainable health.
The human body is far more complex than a steam engine. It’s time to move beyond the outdated calorie model and embrace a nuanced understanding of nutrition that considers hormonal and metabolic effects. The path to optimal health lies in nourishing, not merely fuelling, our bodies.
