Widespread weight problems are a modern phenomenon. For the greater part of human history and pre-history, man’s greatest priority was getting sufficient food to survive. Human beings evolved over a million years ago as hunter-gatherers. There are still groups of people living in hunter-gatherer communities, which give us an indication of how life would have been for all humans before the advent of agriculture and settled life. As the remaining groups are predominantly in tropical jungle regions or the frozen Arctic zones, however they can only give an idea of the life that people led in the temperate regions before farming developed.
There is no doubt that life is hard for these groups from our perspective. They are often nomadic, since they must move with their food sources. They have few possessions, but of course need fewer things. They use ingenious but rudimentary technology which anyone can understand. They have to expend enormous amounts of energy to obtain food which is found in their living natural state and they must also carry out whatever processing is required to make it palatable. They have to catch and kill living creatures for their proteins. This involves ingenuity and strength since, unless trapped unawares, their prey is intent on not getting caught. The foodstuffs that need to be gathered have to be dug, or cut or harvested. They find these things growing, not lined up on a supermarket shelf, so they have to search for them. In some environments, even though man generally enjoys a position as a top predator, they must also consider self protection. Their environments are potentially dangerous and there will be other hunters who may see a human as potential prey as well.
This all means that the calorific cost of getting food is high. There will be many occasions when a hunting or foraging trip will simply be unsuccessful. There is a similarity between this lifestyle and that of other animals living in the wild, dependant on their own strengths and skills or instincts to provide food and stay safe.
As alien as this is to my life and to yours, human beings all lived this way for the greater part of our history. The settled lifestyle which came with agriculture only started to come about over the last ten thousand years. Humans were hunter-gatherers, dependant on the natural environment and their skill as hunters for hundreds of thousands of years before farming became the basis of food production and humans began to build fixed places to live.
Crucially we evolved as hunter-gatherers. It was the pressures of that lifestyle which have determined our physical state by deciding which strengths and attributes were most suited to our survival. I do not believe our settled lifestyle has had the chance to have significant influence on our evolution. Advances in medical science together with the particularly human tendency to adapt our environment to suit us rather than to evolve to profit from our environment means that future human evolution is not subject to the same pressures of natural selection that determined our development up to now. I am not an evolutionary scientist, and I cannot see into the future, but my observations and the limited study I have made in this area has brought me to these conclusions.
Where does that leave us with regards to our weight? In common with many other animals, we have an alimentary canal which enables us to digest food and extract from it our energy, protein, vitamin and mineral needs to keep us healthy, with sufficient energy and able to obtain more food and reproduce. Our bodies are crucially able to store excess energy as fat. This is a very important ability, particularly for the hunter-gatherer or indeed any animal which has to find its food requirements from a harsh environment. While we can go for short periods without the proteins, vitamins and minerals required for growth, repair and fighting sickness, we need energy all the time and at certain times we need additional energy, whether we can find extra food or not. This is particularly true for pregnant women and nursing mothers, but also to cope with cold or to keep the hunter going during particularly difficult hunts or when fending off attacks.
Nature’s solution is fat. Whenever we eat foods which provide more energy than is to be used immediately, it is stored as fat for use another time. In this way we can keep going when food is scarce and spread out our energy consumption if we cannot obtain food supplies regularly.
If you have watched any of the documentaries show on television about the societies still leading pre-agricultural lives you will have seen that the people in these cultures are usually not fat. They usually look remarkably healthy, because they lead active lives. They walk, they run, climb trees and undertake physical activity to carry out any of the tasks they need to perform. When they are not hunting, or gathering food, or building shelters, or making tools or clothing or defending themselves, or moving to a new encampment, they rest. Their daily activity burns the calories they consume and they do not become fat as a result. While they will have small fat reserves on their bodies, they would not want to build up excessive fat layers because the weight would slow them down and make them less able to do the things they need to do.
Agriculture produced greater quantities of food and meant that gradually people could specialise so that not everyone was required to work exclusively in food production. Farmers could produce surpluses and exchange them for other goods and services. Other people produced the goods and services which they exchanged for food. The exchange began as direct barter, but evolved into the money exchange systems that have become the lubricant of our current complex economies.
While farmers could produce a surplus which hunter-gatherers could not assure, they still did this through hard physical labour. Other members of society exchanging other skills, or products for the farmers’ surpluses also worked hard and expended energy. Only a small minority had the leisure and ease in their lifestyles which would enable them to become fat.
Society developed and our economies became more complex but many of these factors remained the same. Right up until the second half of the twentieth century, the overwhelming majority of people in all parts of the world had to undertake physical labour. Even those who spent their working lives in the growing service sector had to walk to get around, and used more energy to do everyday things than we do. Keeping house was more physical. Keeping a house warm involved carrying wood or coal, lighting and cleaning fires. Food preparation was just that: shops supplied food in a semi-prepared state and labour was required to turn it into dishes for the table. Before the supermarkets and convenience stores, shopping involved tours around several businesses to get the things that were required. When there were no domestic refrigerators or freezers, shopping was a daily task. Before the washing machines, cleaning clothes was heavy work. Even the first washing machines did not eliminate physical effort.
Until the post Second World War era, food was relatively expensive for most ordinary working people. Social studies revealed considerable malnutrition in most countries, particularly among the working classes. Energy was also costly. When houses are cold, we use more calories just to keep our bodies at the correct temperature for our metabolism to function.
Several elements changed at the same time in the post-war period, particularly for the developed nations and the standard of living improved. Most people became considerably wealthier than they would have been in earlier times. Food became cheaper. Investment into agriculture meant that production increased and prices dropped. More people had disposable income and the consumer market blossomed. They were able to buy cars, domestic appliances, central heating systems and all the other conveniences of our modern lives. Industry and the services have also found ways of reducing the physical effort required for most forms of work. Automation and labour-saving technology have all contributed to reduce our daily calorie requirement. Our working day is shorter and our holidays are longer than they were a few generations ago. We travel further, but we are more likely to take the car, rather than walk half a mile to the school or the station. We drive to the supermarket once a week, rather than tour around half a dozen shops on foot every day.
Another important change has been in food processing. Not only has food become cheaper in relative terms, its energy content has increased. Far more of the food we buy has been processed prior to purchase. Whether this is the pre-washed salads, or the fully prepared microwave meals, we are less likely to carry out as much food preparation at home as our grandparents did. We tend to buy ready-baked cakes and biscuits, we are more likely to buy jars of jam than make our own.
The food processing industry has also increased the energy content of our food and has tended towards ingredients which release energy more easily. We eat more refined sugar, white flour and other starchy foods which require little digestion. This is a direct result of our digestion and our tastes. We are instinctively attracted to foods which will provide us with sugars quickly. We are attracted to them because they are so rare and difficult to find in the natural environment. They were the real treats and consequently posed no risk. The situation changes completely when they are readily available at low cost and begin to dominate our diets.
The growth of food processing has been long. Ever since the first bakers and specialist butchers opened their businesses, the industry has existed. The change has been the enormous range of prepared products available and our increased ability to buy them. More and more households depend on two incomes. When a family relies on a salary from both husband and wife, there will be less time available for the preparation of food. It is logical that such a family will tend look for meals that require less effort, whether it is the microwave meals or the takeaway dinner.
Let me state straight away that I am not simply condemning the food processing industry or the supermarkets or the restaurants. I do not subscribe to the simplistic labelling of food as “healthy” or “unhealthy”. Unless something is poisonous – in which case it is not a food – all foodstuffs have their place in the choices available to consumers. I do believe that one needs to be cautious with foods containing high amounts of fat, particularly transfats, as well as refined sugars and starches. I am particularly wary of corn syrups, which are a cheap source of sugars in a format particularly adapted to processed foods. None of this should be taken to mean that I think consumers should not choose processed foods. I advocate a balanced diet with appropriate quantities of all types of food.
We have reached a point, then, where we now have easy access to ample quantities of high calorie foodstuffs at the time when our energy requirements have dropped. We have reached this position while we are still using our hunter-gatherer bodies which process the food we eat very efficiently, extracting all the energy available and storing any surplus as fat. Our bodies are conditioned not to believe this bounty can continue, so we need to lay down the fat. And that is what we are doing.
Many people are now getting too fat. While our bodies evolved to be good at building up the fat, the circumstances in which we live are not those which conditioned our evolution. Our systems are aware that getting too thin, being malnourished, will lead eventually to the curtailing of our lives. It turns out that getting too fat results in other very serious health problems. It is relatively recent in our history that we have had to consider the risk of excessive fat. Cardiovascular problems, increased risk of stroke, diabetes, cancers, fertility problems, and many other sicknesses are related to carrying too much weight. The World Health Organisation recognised a worldwide epidemic of obesity in 1997.
More generally, I can vouch for the fact that being overweight means you have less energy, you are more prone to fatigue and generally less comfortable. I believe we instinctively know that things are not right when we are not at a healthy weight and this can cause depression.
Not only can being overweight cause depression, an inability to correct the problem can increase the depressed state. Depression itself can also be a factor in causing weight problems. Comfort eating is an attempt to resolve depression. It does not work. When we eat comfort foods we are eating too much of the easily obtained sweet tasty foods we are surrounded by, not because we are hungry, but simply for the instant fleeting pleasure of the intense sweet flavours that refined sugars, carbohydrates and fats give us. Whether the depression is caused by being fat or by other things, it can quickly become a factor in weight problems.
Paradoxically the iniquities of the world mean that while those of us fortunate to live in the developed world are struggling with the problems caused by our excess supplies of cheap food and a third of the population predicted to be obese in the near future, this is not the case elsewhere. In the developing world malnutrition remains the biggest dietary concern. While I hope to help you with your excess weight, it is important to remember that we are suffering as a bi-product of our good fortune. This does not lessen the importance of the consequences of excess fat.
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