Our ancestors were hunter-gatherers and over hundreds of generations they subsisted on a diet made up almost entirely of hunted animals and gathered vegetation. Roughly 6,000 years ago agricultural practices were becoming more commonplace and sugarcane and various grains were domesticated. Agriculture has been a significant force in the evolution of human civilization; unfortunately our bodies evolve much more slowly than societies. So while a lot can happen to a city in 6,000 years, our genes and body systems have not changed very much. Indeed, our dietary and health needs are very similar to those of our hunter-gatherer ancestors.
Even from a historical perspective, we can see that agricultural societies that processed sugars and grains for consumption suffered during the transition. Moving from a diet rich in meat and vegetables to one dominated by grains, civilizations experienced reductions in lifespan as infant mortality and infectious disease rates increased. You may even say we’re still in a transitional period as the human body has yet to adapt to a diet that is high in processed grains and refined sugar. The explosion of carbohydrates in our food sources is the primary factor contributing to obesity in Western society as well as the unprecedented rates of chronic disease such as diabetes.
The health consequences of overindulging in refined sugars and grains are well documented. Sugar impairs the activity of white blood cells and subsequently immune system functioning. Limited storage capability for excess carbohydrates means your body converts carbs into body fat. Plus, today’s sources of simple sugar (i.e. natural sugars found in fruit) and whole grains are not the same as our ancestors – we access only highly processed varieties of these foods. That means the grains are stripped of their fibre and protein so they have little nutritional impact. While fruit contains vitamins and nutrients, refined sugar is essentially empty calories – your body gets nothing from it.
If you think of the body as a machine that has been fine-tuned over millions of years, you can see how 6,000 years is merely a blip. Now, let’s take a closer look at the way energy is processed and stored. Insulin is a hormone that functions to convert excess glucose in your blood (aka “blood sugar) into fat for storage. This is a critical feature of our body machines because our ancestors often had to adapt to long periods without consistent access to food. Natural disasters, weather patterns such as drought, and other natural events could significantly limit our access to food from animals and vegetation.
However, in today’s developed societies, access to food is a given. We’re rarely faced with the prospect of starvation, and fat stores are less important for survival. Unfortunately, snacking on processed sugars and grains leads to a spike in blood sugar followed by the secretion of insulin by the pancreas to store that sugar as fat for the future. With constant access to food, we never need to access our stored fat for survival. As you can see, there’s no place in our diet for sugars and grains.