Evolution wants us to get fat when calories are abundant to survive periods of cold, famine and illness.
Unfortunately, evolution is no longer our friend and our environment is changing much faster than our genes could ever adapt, existing in a world with unlimited calories.
Not all these calories are created equal and not all are metabolized the same way by our
body.
One abundant source of calories in the modern diet is fructose, a form of sugar found in almost all fruits so it is a key element of many animal diets, from humming birds to humans.
Unfortunately, we humans have a unique ability to turn calories from fructose into fat.
Before you panic, it’s unlikely you will become obese by having several pieces of fruit every day as part of a healthy diet.
The fructose will come wrapped in fibre and water which allows our metabolism to cope with the calories ingested.
However, if you consume high amounts of fruit alongside regular meals, or if you drink lots of fruit juice, fizzy drinks or fruit smoothies you may want to read on.
When we metabolise fructose, we produce large quantities of uric acid which is best known as a cause of gout but has also been associated with elevated blood pressure.
It also appears uric acid allows us to create more fat from fructose calories due to an evolutionary sidestep which would have allowed our ancestors to fatten up in summer on fruits to see them through the winter.
The metabolism of other foods, such as meats, cheese and beer, will also create uric acid which points to why gout was often and ironically known as a condition of “good living”.
In modern times, this fat-storage mechanism has outlived its purpose as we can literally swim in a sea of fructose due to its widespread use as a sweetening agent.
Foods and drinks such as fruit juice, fizzy drinks, fruit smoothies and some salad dressings contain high amounts of fructose, driving fat gain.
Fruit is much better consumed in its natural form, as once placed in a blender the fibrous tissue which slows the entry of sugar into our bloodstream is broken down and we produce a product much closer to a juice.
There is another issue with the metabolism of fructose when compared to glucose.
When we break down glucose, we almost immediately have more energy to play with even though we use some of our own stored energy to break it down.
A sort of spend some money to make more money kind of scenario.
Our body needs to be careful about how much we speculate though and when it comes to glucose, our body knows when to stop committing stored energy to this equation.
When it comes to fructose, we can’t quite put the brakes on it in terms of how much energy we use to break it down and the result is a perceived drop in energy levels.
Therefore, fructose basically tricks our body into thinking we are energy depleted and we need more food to store as fat.
A few may be thinking about the barrel of fizzy drink that accompanies certain fast food outlet meals and the potential impact. Do you really need a dessert or has your brain been tricked?
If you could benefit from some helpful guidance on becoming a little more physically active or understanding your diet please self-refer to our Thrive programme by visiting www.lornhealthyoptions.co.uk
Rob Graham, lead exercise professional, Healthy Options.