Food Groups, Calories and the Dangers of ‘a Little Knowledge’
To understand where all the bad advice and where all the fad diets on the web come from, you first need to understand a little about the history of diet advice and what we have historically thought about our food over the years. Because this is how things have gone a bit wrong – and it’s with the best of intentions.
A long time ago, we didn’t know anything about food or about nutrition. We simply knew that eating too much made you fat and eating less made you less fat. Back in those days though we were also much more active and didn’t spend most of our time sitting down on the computer.
Over the years though we became more sedentary and at the same time, developed better techniques for studying what food actually did to us. We were thus able to break down our food into major ‘groups’.
Those food groups included:
• Fruits and Vegetables
We learned that each of these food groups would impact the body slightly differently and provide different benefits and weaknesses. Over time though we would learn that some of these definitions were a little arbitrary (and different versions of this list exist depending on where you look). For example, fruits and vegetables are actually a form of carbohydrate but differ in the way they release sugar into the blood stream owing to their GI index. We’ll be looking at that in much more detail in future chapters.
Everything we eat also provides us with micronutrients (amino acids, vitamins, minerals, essential fatty acids etc.) which perform important roles in the body and help build tissues and provide a range of functions. Meanwhile,foods also contain ‘calories’ which represent the amount of useable energy. The more calories in a particular type of food, the more energy it gives us. If we eat more calories than we burn though, they get converted into fats and stored in the body. To continue the car metaphor a little further,imagine that you were stopping at a gas station but you didn’t know when you would next have the opportunity to fuel up. In all likelihood, you would take extra fuel and keep it in a can of some sort as a backup in case you ran out in the middle of nowhere.
Calories were originally worked out as being the amount of energy required to heat one kilogram of water to 1 degree Celsius at sea level. This is still the system we use today. And yes, it is completely arbitrary and outdated at this point. And if we look at the major food groups, we can see that they each contain a different amount of calories. While carbohydrates and protein both contain 4k-cal (kilocalories) per gram, fats contain 9k-cal per gram. And seeing as fat is what we’re trying to get rid of in the first place anyway,the ‘obvious’ conclusion to draw from all this would be that we should reduce our intake of fats. Studies meanwhile appeared to show that diets high in fats would lead to heart problems and bad cholesterol and as such, some basic diet guidelines were formed.
The Problem With Modern Advice – Based on this basic knowledge of nutrition, it was established that we should try to:
Limit our overall calories
Eat a nutritious diet
This was the advice that most health institutions recommended for a long time – and many still do today. This also includes the NHS in the UK which still recommends low fat diets as being the healthiest way to lose weight. Meanwhile, this also led to many processed foods being released with fortified mineral and vitamin contents. Eating a vitamin tablet in the morning should be able to provide you with all your required vitamins and minerals and from there you can then eat whatever you want so long as you keep your intake of food low. As we’ll see in a moment, all these conclusions were drawn prematurely and without all the relevant information. Have you ever heard the expression ‘a little bit of knowledge is a dangerous thing’? This is the perfect example of that.