Understanding the Obesity Epidemic
Humanity is facing a problem that it has never had the luxury to have before: too much food, too little movement and too much of the things we are evolved to crave: sugar, salt and fat. That is a gross oversimplification of a complex issue, but it is something new to us as a species. We are not responding well. Since 1975, the number of obese people has tripled. About 10% of children worldwide are obese and 1.9 billion adults, or nearly 1 in every three. In the Americas, childhood obesity is nearly 30%, and nearly half of adults are overweight or obese. This is a true epidemic and one that looks very hard to solve by governments. The very ways we live our lives cause obesity, it seems humanity must take an extra step and change how we live, if we want to live long lives.
Here we discuss obesity, its causes, its effects and what we can do about it.
What is Obesity?
Obesity is defined in several ways but the most common is the body mass index (BMI). The weight of the individual divided by their height. An overweight adult is an adult with a BMI of 25 to 29.9, an obese adult is one that has a BMI of over 30.
For children, it is more complex. There are thinness grades and different scales for girls and boys. A BMI of 23 or more is overweight, 27 is obese. This changes with different populations as children and adults from different parts of the world can have different physiologies. For pre-pubescent children over 6, if you cannot see their ribs, they are probably overweight. Overweight children have become so common that the morphology of children, or their standard shape, has changed, along with our expectations. Parents are not realizing their children are obese because obesity looks normal.
What Causes Obesity?
Obesity is caused by several factors in most people. These include inaction, eating too much, and eating too much fat and sugar. Obesity has gone from a problem of the rich world to a problem of the poor world, as jobs and diets change and the availability of good quality, healthy food has actually decreased in urban settings. More people are doing less physical activity than ever, especially children. Cheap food is usually packed with preservatives, especially salt and sugar. When children are fed this and spend a lot of their time looking at screens instead of playing, they become overweight or obese. To understand why we are getting so fat, it is important to look at the evolutionary context we find ourselves in.
Why is Obesity Happening Now?
In the million or so years humans have been around, humanity has been in a constant battle for resources. Fat, salt and especially sugar were hard to come by and a lot of energy needed to be expended to obtain them. Hunting is demanding work, salt is rare, sugar was only available at certain times of the year. This meant that evolutionary pressures forced humans to seek out these rare nutrients whenever possible, and when we found them, to eat as much as possible.
Skip forward a million years and the majority of humans have solved the problem of scarcity. Now there is an easily available abundance of high fat, high sugar and high salt foods that we don’t have to work physically hard to obtain.
Unfortunately, evolution has not caught up. Only 100 years ago, most humans lived drastically different lives: they had physically demanding jobs and active lives, sugar and fat were luxuries and hard to obtain. Famines wreaked havoc, starvation was commonplace, diseases caused our lives to be short and often painful. In the past 100 years, humanity has made massive progress. Famines, when they happen, are man-made (see Yemen). The leading cause of death has gone from pneumonia, usually an infectious disease, to heart disease, largely influenced by lifestyle. People are living longer, healthier lives. Or at least, some of us are. The current generation is the first in history that is likely to live a shorter life than the one that came before. The reason for this is obesity and the health risks this entails.
We are, as a species, not evolved for the conditions we have created for ourselves. Humans spent hundreds of thousands of years being forced by evolutionary pressures to be excellently adapted to periods of fasting, low salt and sugar diets, hard physical work from a young age. Those pressures have changed almost completely, but we have not had time to catch up. Our genes are telling us to seek salt, fat and sugar as much as possible. They are not programmed to realize that those resources are abundant and do not need to be sought.
So we eat, and we eat. And we sit around, eating. Humans have never done this before. In China, historically, being fat was a sign of wealth: if you could afford to sit around and eat, you were doing well. Now, it is more a sign that you are poor.
Obesity can be a sign of undernutrition. It can occur even when the person is eating the “right” number of calories, they are just calories from the wrong sources. Cheap food lacks good nutrients in general, so a person can be undernourished and obese at the same time.
Obesity in America
Americans have the dubious honour of being amongst the fattest people on earth. Some groups are more obese than others: non-Hispanic black people have the highest rates of obesity, at 48.1%. Hispanics have a rate of 42.5%, non-Hispanics 34.5, and non-Hispanic Asians 11.7%. This huge variation is due to several factors, including socio-economic background, poverty, education (in women at least), and biological factors such as genes related to obesity. This is far from being properly understood, but the genetic heritage of an individual does affect their likelihood of becoming obese.
A culture that relies heavily on motorized transport, that eats huge amounts of meat and high sugar foods, that has a service based economy that does not entail hard physical work, this is a culture that is primed for an obesity epidemic. In hindsight, it looked inevitable: people wanted what came with freedom and wealth, they just were not prepared for it. And so the American people got fat. But then the economics of food adjusted to their demands. Pre-packaged foods became cheaper than buying the raw ingredients. High sugar and salt foods tasted better than home-cooked food. Economic pressures forced people to buy cheap food, but this was not the cheap food of 50 years before, this was nutritionally terrible food.
There is increasing awareness in America about nutrition and obesity but the huge levels of poverty in the world’s richest nation make choices about exercise and nutrition impossible. Many parents are forced to feed their kids food they know is bad for them but they have no choice as the healthy options are too expensive. They know they should exercise more but they do not have the time or the facilities, or the money to do so. It is a common perception that people do not know that what they are doing is bad for them, but this is not true. For many, they simply have no choice.
Obesity in the World
As the American way of life spreads around the world, more people are getting as fat as the Americans. Childhood obesity rates in Africa have doubled since 2000. 320 million Chinese people are now obese. While some of this is in the newly rich people, the majority are those who have been entered into the new economic system but have not achieved great wealth. In other words, the poor. They face similar pressures to the American poor: whereas their parents or grandparents might have grown their own food and faced the risks it brings, now they can only buy their food in shops. They can only buy food that they can afford: food that is cheap to produce and full of flavour enhancers (sugar, fat and salt) to cover up the lack of nutritional value.
New jobs are more often jobs that involve sitting down all day and driving to and from work. Televisions and computers are cheap entertainment, there are few areas children can play in safely in densely populated cities, often the air is too polluted to go outside and exercise. Infectious diseases are still rife in low and medium income countries, as is malnutrition. This is known as the “double burden of disease”, where countries are facing both undernutrition and obesity side by side, even in the same households.
This is all adding up to an obesity time bomb and a healthcare burden unlike any humanity has ever faced.
The Effects of Obesity
Obesity causes diseases. These range from diabetes to cardiovascular disease, to arthritis and cancer. As a person’s BMI increases, so does their risk of developing a noncommunicable disease. Diabetes and heart disease are two of the world’s largest killers, largely because of obesity. The costs to societies of these diseases are enormous and are very likely to increase in the future.
It is not just the cost of surgery, drugs and treatment; it is the loss of working years, the more time taken off, the lower productivity of an ill person. These all place a drain on the workings of society. The cost to the individual is immense as well. Being obese, aside from the health risks, affects confidence, physical abilities, can cause depression and anxiety, reduce sexual performance and confidence, and simply make someone very uncomfortable all the time.
What to do About Obesity
Clearly, societies need to do something about obesity. If the rates of obesity continue to rise, humanity faces a serious risk of erasing a huge amount of progress in health. Nobody wants to die before their parents, but this generation might.
For the Individual
For ourselves, we can make better choices. The things proven to reduce obesity, the risk of developing obesity and the risks that come with it are:
Exercise – at least 60 minutes a day for children, 150 minutes a week for adults
Eat less rubbish – reduce intake of fats and sugars, especially sugars
Eat more healthy food – fruit, vegetables, legumes, whole grain foods and nuts
Other factors include having balanced medication, stopping smoking and treating mental health disorders. Some surgeries are available but are best avoided if possible.
All that is easier said than done: it usually requires help. So here is what we can do as a society.
First of all, study what works and what does not work. Good science is essential for good governance. There is a lot of evidence that shows that government action can work when applied properly.
The next generation is crucial in dealing with obesity. If we can get it right with kids, they can pass on and strengthen the message. This means education for children about diet, the availability of healthy food in schools, play areas and activities to engage children, expanded monitoring and available healthcare for children, spotting obesity in children and putting them into a proven weight loss program.
More generally, health awareness campaigns, a minimum “living” wage that allows the purchase of healthy food, more parks and play areas, cheaper or subsidized gyms and sporting facilities, mental health treatment to be universally available, support and guidance for those at risk, jobs that can be adapted to standing up instead of sitting down, the list goes on.
Our society has work to do. We are facing strong evolutionary pressures that we do not understand. It seems that a fundamental change in the way society works is the only thing that will keep us healthy.
Obesity is much easier to prevent than to treat, but it is treatable. Support is available on the web for those who need information and guidance. By losing even a little weight, the likelihood of dying of an obesity related disease falls substantially.