Does it make sense to eat fat and sugar?

Does it make sense to eat a load of fat and sugar and spend the rest of the day lying on the lounge? Form a health and fitness perspective maybe not, however from an evolutionary psychology perspective it makes perfect sense. Remember that evolutionary psychology is based on the fact that humans evolved on the African plains tens of thousands of years ago, and that much of our current behaviour is based on those early survival strategies.

In the wild there is very little fat available. All possible prey is usually very lean; after all a fat zebra that could not run quickly would soon become dinner. If you every have every watched a David Attenborough show you might have noticed that when lions catch something, say a zebra, they don’t start by eating rump steak or eye fillet. The lions fight over the live or the kidney because these are the fatty parts of the catch. For a predator eating fat makes evolutionary sense as fat is energy.

Human behaviour and sugar are even more intertwined in our evolutionary past. The only sugar available in the wild is via fruit and fruiting plants and animals evolved together. Plants encase their seeds in soft fleshly fruits. Animals eat the fruit and excrete the seeds in a clump of soft damp poo, far from the parent plant. For the animals in the wild sugar is an incredibly valuable food source providing instant energy. Plants that offered the sweetest fruits stood the best chance of having their seeds distributed. Of course co-evolution meant that over time the sweetness of fruits increased and some animals, humans included, specialised in eating fruits. Of course in the wild fruit was only available for a very short period in spring and early summer.

So we are genetically programmed to eat fat and sugar. It appears that evolution that served us well on the plains of Africa when food was at a premium now works against us. However recent research might come to the rescue. It appears that when we eat fat we quickly become full; there is a limit to how much fat we can eat. The same seems to apply with sugar. As an experiment try eating a couple of spoons full of sugar and you will quickly realise there is a limit. However, and I not recommending this, you will be able to drink several cans of soft drink, with about ten teaspoons of sugar in each can. Recent research is showing that foods that combine both fat and sugar confuses our bodies and the automatic shut off circuit does not seem to activate. In nature, foods that combine high levels of both fat and sugar are extremely difficult to find. In the western diet food that contains both fat and sugar are very very common, as an example, ice cream. Ice cream is basically dairy fat, and sugar and we can eat buckets full of ice cream.

So although we are genetically programmed to eat fat and sugar it is processed food that causes us problems.