Fats in food

Mmmm, that cake looks delicious. Yesss... Loaded with fat! There's fat in almost everything tasty: cream, butter, nuts. Yes, and in avocado,olives, and cheese.

And in us humans. We have a lot of fat in our bodies. We have fat under the skin. This protects us from the cold. We have fat under the soles of our feet - and surrounding the vital organs, to protect them from damage.

We have lots of fat in the brain - indeed, around all nerve cells. And so we have a little fat here, there, and everywhere in the body - as a kind of reserve supply. We can draw on this fat if we're short of food, or if we're sick and can't eat. Fat could be called the 'pure energy bomb'. It contains twice as much energy as the same amount of protein or carbohydrate.

Thanks to the ability to use the body's fat as a reserve-tank, humans have survived in times of little food. And when there was plenty of food, we could eat a little more - and store the extra in the body as fat. But we don't need to eat only fat to store fat. Proteins and carbohydrates serve equally well. The body first turns everything into: energy!

This is part of the digestive process. In the stomach and duodenum an enzyme breaks down the fat molecules into different kinds of energy parcels. Part of this energy is used at once to keep the body going. But what's left over is stored as fat. This ability to store fat is vital for humans.

But it can also be problematic. If we take in more energy than we can use, we become overweight. Adults who are overweight are at higher risk of certain diseases - for example, heart problems. It's the total amount of energy that matters - whether the energy comes from carbohydrates, proteins, or... fat.

So it's not the fat in food that makes you fat. In fact you have to eat fat, to feel good. Partly to get energy... ... and partly because fat contains substances that are vital for the body - for example, vitamins. In nature we find fat in both animals and plants.

Fat from plants - vegetable fat - is usually liquid at room temperature. And fat from animals - animal fat - is usually solid at room temperature. Animals build fat in a similar way to humans. A portion of the carbohydrates, fats, and proteins eaten are converted to stored fat by the body. But plants need help from the sun.

First they convert water and carbon dioxide to glucose - with the help of sunlight - by photosynthesis. Plants then join together the small glucose molecules into long carbohydrates: as starch - and cellulose. And finally, plants convert some of the starch and cellulose into fat. When a plant builds fat, most of this is collected in its seeds, nuts, berries, or fruit. Why?

Just like humans, plants also need to store concentrated energy. Look at this olive. Now it has to fend for itself. It takes a lot of energy to develop a root and a stem with leaves. And this energy comes from the fat in the olive.

But if you eat the olive before it germinates, it gives you energy instead. We can also make use of this energy by pressing out fat from seeds, nuts, or... like here, from olives. So we get oil in which to fry food or to pour over salad. Three decilitres of olive oil contain as much energy as you normally use in a day: equivalent to two kilos of cooked pasta... ...

or four kilos of apples. We also get fat from animals... ... by eating meat, ... or from the milk of cows, goats, or sheep: Milk from which we can make butter... ... and cream... ...

and ice cream! Mmmm, I could totally demolish that cream-cake. No, that one - filled with nut-cream.