Weight gain/weight loss.
Summer in the city, lunchtime on a weekday. I walked through a park on my way to a meeting on a main street. It was a lovely day; clear blue sky and warm sunshine. The park benches were all occupied with people eating their lunch. I don’t usually peer into the lunches of strangers but I had been mulling over the obesity epidemic as a blog post topic – call it my research.
I stopped and took a panoramic view of what people were eating. Here’s what I saw – a guy, eating out of a cardboard box – bright orange noodles with some thin slices of vegetables; two girls with plastic black boxes – penne with tomato sauce; subs and sandwiches, more black containers, cans of pop and iced tea. I didn’t notice any obvious bags from home, and there were far more sweetened beverages and cups from coffee shops than bottles of water. Once I got onto the street I walked by a pregnant woman on a park bench, eating a virtuous salad from a container from home. She was sitting a few meters away from an intersection where close to 3000 cars were driving by during the lunch hour. Her attempt to eat well was commendable, but she probably would have been better off finding a place to eat 500 meters (roughly half a mile) away from the main road.
Lifestyle is only part of the equation
There is no question that that many of our modern food choices contain more sugars and empty calories than they used too. Add that to the fact that we eat more and exercise less. For those who are motivated to change their lifestyle, there are many diet and exercise options available. But even then, many people can become frustrated at the slowness of the process.
Most people do not intend to be fat. They don’t want to be at risk for diabetes, cardiovascular disease, or cancer. Is the obesity epidemic just about a lack of self-control – poor diet choices and not enough exercise? Consider this: other animals have not changed their lifestyles or behaviours, but they are getting fat too. Over the past several decades, average weights have risen among primates and rodents living in research colonies, as well as wild rodents and domestic dogs and cats. Even pasture-fed horses are becoming obese. The increase in weight among animals living in varying environments suggests common environmental factors. The scientists who published these observations referred to these animals as the proverbial canaries in the coal mine because they are warning us that diet and activity level are not the only factors contributing to the obesity epidemic. Environmental pollutants can alter metabolism and predispose some people to gain weight. We call these chemicals obesogens.
Different obesogens have different mechanisms of action. Some influence hormones like thyroid hormone, and others affect appetite, satiety (feeling satisfied), food preferences, and energy metabolism. For example, common food additives, like sodium benzoate, block the release of leptin. Fat secretes a hormone called leptin, which stimulates the reward centre and tells the brain to suppress appetite. In obese people, the brain has developed resistance to leptin; there is no sense of satisfaction and the need to eat continues.
What do your store in your cupboard?
When I was a medical student, we were taught that fat was just a passive storage space for extra calories. Now we know that this is not true. Fat is an active organ and is part of the hormone system. It secretes hormones and communicates with the brain and immune system. Pollutants which can promote weight gain that are very commonly found stored in human fat include some pesticides, flame retardants, stain repellants and plastics. Some of these obesogens are found in cosmetic and personal care products, or even in the dust in your house, and your body has a hard time eliminating them because you keep adding more.
These same obesogens are frequently found in newborns and help to program an increased likelihood of weight changes later in life. Traffic related air pollution is also associated with obesity in children. A study of pregnant women in Manhattan showed that even prenatal exposures to urban pollution can contribute to childhood obesity. That’s why the pregnant woman, eating her salad, would have been better off sitting farther away from the traffic. Poor lifestyle choices made on behalf of children compound the problem.
Given that these chemicals are stored in body fat, the more weight you gain, the more you become contaminated. And it becomes even harder to lose the weight. So, if you want to get rid of excess fat, exercise and diet may not be enough; you should also try to eliminate chemical exposures and learn more about how to detoxify and eliminate what’s already in there!