If I ask most people, they’ll say it’s that person’s fault, perhaps not to his/her face, but there will be at least judgement of what the person did or didn’t do to gain weight. Maybe he/she ate too much, or sat on the couch too much, or maybe a bit of both. Either way, most people lay the blame of obesity on the individual and the choices he/she makes.

If it was all up to individual choice, then why is it that with so many people unsatisfied with their weight obesity is so prevalent? It’s not that people want to be obese. Those who are overweight and obese actually still have an anti-fat bias, stereotyping obese people as lazy. Many of these same people would prefer to die earlier or be divorced than be obese. Surely if it’s just a matter of will-power then surely we can change what we do and obesity will go away.

lose weight

The fact is, it isn’t easy to prevent or eliminate obesity. If it was, the weight loss market wouldn’t be a multi-billion dollar industry. It would be a bust, as weight loss would be so easily achieved there would no longer be any business. We also wouldn’t see the number of people with obesity increasing year after year: a 3-4 fold in the US increase since the 1960s.

With nearly 1 in 3 adults who are obese in most developed countries, chances are you or someone you know is obese. Of course individual choice does have a role but to say millions of people decided to become obese all around the same time, is absurd.

Willendorf- small

Obesity isn’t new though. Ancient artifacts such as the Venus of Willendorf, from around 30 000 BC which depicts a woman with ample body fat, gives us some indication that obesity has been with us for a long time.

Obesity is also present in every society. In places such as China, that are generally associated with being thin, the prevalence of obesity has doubled in the past decade. Even in the highly active Amish populations, who live a lifestyle similar to that in the late 1800s, approximately 8% of adults are obese. Although physical activity, while crucial to lifelong health, is not an ideal method for weight loss.

The fact that people can grow up and live in the exact same environment yet some end up overweight or obese, while others don’t, tells us there is likely a genetic reason for a person’s body size. Conversely, we all know of the person who can eat a lot yet not gain weight, even if he/she doesn’t exercise, and this is likely genetic as well.

twins2

There is widespread agreement that our genes have a role in our body size and risk for obesity and early studies of identical twins (who share the same DNA) who grew up separately support this. Even with overfeeding, identical twins had similar amounts of weight gain. However, how much of our body size is due to genetics is up to much debate. And while there may be dozens or hundreds of genes related to obesity, there are very few people who are obese as a direct result of their genes.

More recently we have learned that modifications can occur to genes that can turn the genes on (active) or off (inactive). The genes themselves are the exact same but a modifying molecule (methyl group) attaching to the gene can turn it off. These modifications can also be inherited and this area of research is called epigenetics. So two people may have the same genes but in one person it can be turned off and in another turned on resulting in different appearance or some other difference. Even identical twins may not be identical.

DNA

Epigenetic changes to one’s genes (or DNA) can occur as a result of age and/or environmental exposure. Much attention has been focused on pregnant women and their children. Studies in animals indicate obesity during pregnancy leads to offspring more likely to have risk factors for heart disease and obesity. Similar associations have been reported in humans. Studies of children born during the Dutch Famine have a greater risk of obesity and this greater risk is also passed on to their children, indicating some sort of inheritable aspect that may be related to epigenetics.

However, genetics do not mean destiny. Even if a person has a genetic risk for obesity, it doesn’t mean that person will be obese or even overweight. What environment, or lifestyle a person has, can still be a major factor. People with a genetic risk who were regularly active had a much lower chance of being obese. Likewise, one’s diet can also enhance or reduce the risk for obesity even in the presence of genetics. In this context, we might think of genes as bullets in a gun, but the environment is what pulls the trigger.

Indeed, while children of obese parents have an increased risk for obesity themselves, and share genes, these children also share a common environment. Just like studies of twins can identify genes related to obesity, these same studies can also demonstrate the role the environment has. Adopted twins show some association of their body size with their adopted parents who are not biologically related.

People_walk_to_get_to_places

In previous blogs I have written how our environment can effect our physical activity and our diets. It’s therefore likely that our environment can also have a role in whether a person is obese or not. While the research in this area is limited and the findings not always consistent, community-wide programs have been shown to reduce obesity in children. The rapid pace at which obesity has increased also points to environmental changes as a cause since our genetic make-up takes many generations to change, and not just decades.

In the end, our individual choices do play a strong role in our health but our choices are limited by the options presented to us. On a large scale, if we live in an area with only fast food restaurants, we’re more likely to eat fast food. Similarly, if we are at a work meeting with cookies on the table, or even have a candy dish beside us, we’re more likely to eat a cookie or candy. We may not even be hungry.

While we can’t change our genes (yet?), we can advocate for communities that support healthy living and also look to see how we can change our own immediate environment. The solutions to obesity will need to reflect the problems and causes. We got to where we are as a society and it will be as a society that the solutions need to be focused. Blaming individuals is not productive as it glosses over the real causes that need to be addressed.