Is it something that must give us pleasure and reward our senses, or is there more to it?
If you look up the meaning of the word food in the Macmillan Dictionary, you will read
Food n. That which is eaten to sustain life, provide energy, and promote the growth and repair of tissues; nourishment [Old English fōda, "nourishment"].
Clearly, food has a very important role to play in keeping us alive, healthy and energised. As important as it is to satisfy the senses, it is secondary. Put it this way: if the food you eat gives you a short term pleasure after which you feel bloated, tired, lethargic and depressed, then you are not eating food. It is more likely a man-made imitation with convincing marketing.
The question then becomes: How do we determine which substances are truly food and which are not? Which nutrients are essential for life? What can't we live without? Which components, if absent, lead to disease?
There are vital substances that we need a lot of, that's why they are called macro-nutrients. These are proteins, fats and carbohydrates. However, there are only essential proteins and fats because our bodies CANNOT produce them, we have to get them from our food. There are no essential carbohydrates.
Essential amino acids are the building blocks of protein. They are needed to make the proteins that make up tissues such as muscles, hair and nails.
Essential fatty acids are the building blocks of fats. They are essential for building and maintaining the membranes of your trillions of cells and supporting brain, nerve and hormone function.
We also need smaller amounts of substances called micronutrients. These are vitamins and minerals, and again we can only get them from our food.
Vitamins are involved in healing wounds, boosting your immune system, converting food into energy... the list goes on.
Minerals are essential for strong bones (think calcium), heart rhythm regulation (think magnesium) and much more.
All foods are NOT equal in nutritional value. If they were, there would be no hidden hunger. It exists in every single country in the world, and yes, that includes the so-called developed countries. It is a severe lack of vitamins and minerals. It is hidden because there are no immediately visible symptoms like in a famine situation where people begin to deteriorate quickly and visibly. The health effects of hidden hunger become visible in the long term.
In 2022, The Lancet published an article on - "Micronutrient deficiencies in preschool-aged children and women of reproductive age worldwide". The consequences can be severe:
"Deficiencies of iron, vitamin A, zinc, folate, vitamin B12, vitamin D and iodine can all have serious consequences, including increased susceptibility to infection, birth defects, blindness, stunted growth, cognitive impairment [this affect a person's ability to think, remember, reason or make decisions], reduced school performance and work productivity, and even death".
So what is it that qualifies as food?
A study published in 2022 by Frontiers on "Priority Micronutrient Density in Foods" looked at different foods consumed around the world (meat, fruit, vegetables, dairy, legumes, cereals).
The study ranked foods according to how well they provided essential vitamins and minerals - including iron, vitamin A, zinc, folate, vitamin B12 and calcium - while keeping calorie intake low. Each food was rated as very high, high, medium and low for vitamin and mineral content and overall density. For a food to have a high nutrient density, it must provide more essential nutrients per calorie.
The study found that the top sources of essential micronutrients were "organs, small fish, dark green leafy vegetables, shellfish, crustaceans, goat, beef, eggs, milk, canned fish with bones, mutton and lamb. Cheese, goat's milk and pork are also good sources and, to a lesser extent, yoghurt, fresh fish, legumes, teff and canned fish without bones.
The study also looked at the average energy requirements of a moderately active person and recommended intakes for different groups: Children 2-4 Adolescents 10-19 Women 15-49 Pregnant women 15-49 Adults 25+.
The charts below look at the kcal and grams needed for an adult aged 25+ to get ⅓ of their daily requirements of iron, vitamin A, zinc, folate, vitamin B12 and calcium.
What the table below means is that if you buy just 7g of liver, which is 11kcal, it will provide a third of your daily requirement of essential vitamins and minerals. Contrast this with whole grains, you would need to eat 852g of pasta, rice or bread, or 1586 kcal, to get one third of your needs. This is what empty calories look like.
The study also looked at the iron requirements of adults aged 25 and over. Here we see a similar pattern. 37g of liver (59 kcal) will easily give you a third of your requirement. For wholemeal, you need 377g (702 kcal) to cover it.
