The new obesity

A growing number of people are unable to shed those extra pounds despite strict diet regimes and long hours of workout. Evidence shows that the toxins in the environment could be playing the spoilsport. They modify the body’s physiology and make it difficult to lose weight. While the West is waking up to the complex linkages between chemicals and obesity, realisation is yet to dawn on doctors and researchers in India. Vibha Varshney, Dinsa Sachan and Sonal Matharu report on the new trigger for obesity and the way out

By Vibha Varshney, Dinsa Sachan, Sonal Matharu
Last Updated: Friday 05 July 2019

The new obesity


Obesity has just slipped out of the grasp of mathematical logic: if one burns as many calories as one consumes, one will not gain weight. Today it is easy to spot people in jogging parks, aerobic centres and gymnasiums who defy this logic. Take Sundar Rao of Mumbai who weighs 89 kg. He has been trying hard to shed the extra pounds for the past 15 years. A 53-year-old chartered accountant, he religiously takes out an hour from his busy schedule for exercising and has tried all possible diet regimes he could dig out of the massive literature and studies done on weight loss. Rao has cut down on carbohydrates, increased protein intake and reduced the amount of fat he consumes. Eating out is curtailed, fruits have been added to the plate and packaged foods kicked out, but to no avail. For his height of 170 centimetres, he is 19 kg overweight; worse, he continues to gain weight.

imageForty-year-old Sapna Vashista of Delhi has a similar problem. For the past six years, she has maintained a strict diet regime. One hour of yoga or aerobics and evening walks are part of her daily routine. A part-time fashion designer and mother of two, she does most of the housework. Still her weight does not dip below 72 kg. For her height of 165 centimetres, Vashista should not weigh more than 63 kg.

Both Vashista and Rao share the fate of many people who even after hours of slogging on the treadmill and giving a miss to their favourite food are unable to shed those extra pounds. The World Health Statistics released in May by WHO also points to the growing trouble. It shows obesity has doubled across the world between 1980 and 2008. Health experts say overeating and junk food are the biggest reasons behind the rise in obesity world over, but they cannot explain why some people are unable to lose weight when they control these habits.

  Obesogens are all around us, in plastic bottles, carpets, cookware and paper money. Exposure to them is unavoidable  

Moreover, food could hardly be blamed for the increase in weight of babies below six months. Data from a research by Harvard Medical School shows the percentage of overweight infants has nearly doubled from 3.4 to 5.9 between 1980 and 2001 in the US.

Baffled researchers who set out to find the reasons say the toxins in the environment, microbes and rise in temperature also play a role in making people fat. Specifically, exposure to certain toxins, such as pesticides, emissions from vehicles and the material that the plastic bottle is made of, can lead to weight gain. Epidemiological studies suggest everyone, including those not yet born, are at risk. Most such studies have been done in the US.

For instance, a study in the US on pregnant women in New York City showed that women exposed to higher concentrations of polycyclic aromatic hydrocarbons, or PAHs, from vehicular and industrial exhaust and smoke from cigarettes, were more than twice as likely to have children who were obese by the age of seven. The study was conducted by researchers from Mailman School of Public Health at Columbia University.

Paula Baillie-Hamilton, a doctor in the UK, was having a hard time losing weight after pregnancy. Looking for ways to lose fat, she chanced upon an article on how pesticides were playing havoc with animals by inducing hormonal changes in them. It was a eureka moment. She wondered whether hormonal changes due to chemicals in the environment could be playing a role in her inability to shed pounds. A three-year-long research unearthed enough evidence.

There were studies as far back as in the 1970s to show that low-dose chemical exposures were associated with weight gain in animals. She published the results in the Journal of Alternative and Complementary Medicine in 2002. The paper was noticed by many researchers who had observed similar phenomenon in their lab animals. They initiated studies to observe the effect of the toxins on body’s metabolism. Retha Newbold of the National Institute of Environmental Health Sciences (NIEHS) in the US tested Diethylstilbestrol (DES), used in drugs, on mice.

They were treated with 0.001 mg/kg of DES and their weight was measured after four months. While the treated mice had average weight of 40.3 grams, those not exposed weighed 30.7 grams. By 2007, the evidence was so clear that a University of California scientist, Bruce Blumberg, gave these chemicals a name—obesogens.

“There are currently about 20 chemicals that have been shown to stimulate weight gain in rodents,” says Jerrold J Heindel, programme administrator at NIEHS. These chemicals are everywhere—soft drink cans, carpets to paper money. Exposure to them is unavoidable.

The National Health and Nutrition Examination Survey in the US shows similar results. When children between six and 19 years of age were tested for the presence of pesticide 2,5-dichlorophenol—commonly used in moth balls, and room and toilet deodorisers, and previously used as an insecticidal fumigant—it was found that obesity was directly proportional to the levels of the chemical in the blood. The study was published in Reviews on Environmental Health in 2011. Adults with higher levels of Bisphenol A (BPA)—commonly used in plastic bottles—were also found to be more prone to general and abdominal obesity by researchers of the Harvard School of Public Health in Boston. Till date, about 20 chemicals have been nailed for inducing weight gaining tendencies and many more may soon make it to the list. Based on their effect, the chemicals have been christened obesogens (see ‘History of obesogens’).

This does not mean diet regimes and treadmill are redundant. Whether obesogen exposure causes permanent changes in the body leading to obesity is currently under study in laboratories across the world, developmental biologist Bruce Blumberg says. Epidemiological studies give only indications. Direct studies are available only on animals. In his lab in the University of California, Irvine, US, Blumberg is analysing the obesogenic impact of a chemical, tributyltin (TBT), on mice. TBT is a biocide that is used in paints in ships to prevent the growth of algae on the hulls. It has now been banned because it leaches into the sea and affects marine life. Blumberg says, “Prenatal exposure to TBT produces irreversible effects in mice.” They get fatter despite a normal diet because TBT alters their metabolism. “So if you were exposed at a sensitive time during your life such that you have more, larger fat cells and stem cells that are predisposed to become fat cells, you will have to fight a lifelong battle against weight gain.”

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  • Good information.But can we

    Good information.But can we do without or avoid these chemicals ?

    Posted by: Anonymous | 8 years ago | Reply
  • With so many chemicals around

    With so many chemicals around us, it is difficult to avoid exposure. But everyone can try to minimise exposure by simple lifestyle changes  - giving up smoking, drinking water from plastic bottles, washing vegetables before cooking, not using chemical dditives in food and so on. 

    But it would be help more if there are policies to reduce the use of chemicals - for example, not using pesticides in agriculture, using safer fuel. Care is needed to establish what is "safe". There have been some instances when manufacturers have moved from harmful chemicals to those "considered" safe. For example, manufacturers  moved from bisphenol A to bisphenol S in plastics. But studies show that this chemical is harmful too. There should be a  mechanism put in place to ensure that toxins do not enter the environment without being proved safe.

    Posted by: Vibha Varshney | 4 years ago | Reply
  • Here's another strong reason

    Here's another strong reason I really need to go after those coupons for baby formula. You can never be too sure of the food you're buying in regular stores, I prefer to make an extra effort to support a healthier eating and reduce the risk of obesity in my family.

    Posted by: Anonymous | 8 years ago | Reply
  • Well genetics of course plays

    Well genetics of course plays part of it and may be toxins from air could have an effect on weight gain, this reminds me actually of a research i read that the air can make us gain weight from all the acid that comes from the sea.

    But even all this cannot me a huge factor or a simple answer for how we gain weight, because how to gain weight depends basically and in huge percent in what food we eat and the amount of calories on it, and of course some people going to have trouble shedding pounds than other because of not just their metabolism rate but also their inherited genes.

    Posted by: Anonymous | 8 years ago | Reply
  • As an organic vegetarian for

    As an organic vegetarian for over 35 years--and believe me, 35 years ago one could purchase organic fruits, vegetables and beans and rice by joining a collective group that pooled money to get small farmers to grow foods organically--I well understand the difficulties of finding unpolluted food. It changed what my family ate and how we ate. My daughter was already 5 years old, but I had breast fed her until she was almost a year old. She is one of the healthiest people I know, has been since infancy; never runs a fever, gets the flu, cold or other normal illnesses her friends seem to have during cold or flu season. I'm the same way, so it could be genetics. I haven't had a cold or flu, any kind of illness, since 1979 (when I had my tonsils removed). In these times when bottle feeding a baby is considered normal, I suggest breast feeding for at least the first 6 months of your baby's life, or as long as the baby is interested. When my daughter started biting me to see my reaction, I switched her to organic milk. We are all responsible for educating ourselves as to the ingredients in all processed foods and avoiding processed foods as much as possible. People commonly think that organics are more expensive to feed a family, but if you cut out meats and fish, it doesn't have to be prohibitive. You are in control of the ingredients in your soups, stews, sandwiches and occasional desserts. Nothing tastes as delicious as homemade, and a simple dinner of baked organic yams dripping with their own syrup accompanied by organic broccoli or beans takes less than an hour to prepare. Organic baked apples topped with a bit of maple syrup is much better than a store bought cake with a list of ingredients that sounds like a chemical experiment. We should be wary of canned goods, even organic ones, that still use BPA to line cans. Companies want to make a profit, whether store brands or companies like Amy Organics, which still uses BPA-lined cans for its beans, soups and chili. We can all do better. Don't accept plastic bags and don't buy them for home. Waxed paper works just as well. Don't buy air sprays, scented candles for the home, and don't shop at stores that sell products made by slave labor of children and adults. As Jiminy Cricket said, "Let your conscience be your guide." Good words to live by, once we have researched well and developed the conscience necessary to combat the endless propaganda we are barraged with.There's a right and wrong way to live. The right way will lead you to new ideas, new paths to follow, make you stronger and more active. The wrong way will make you unfit, ill and unquestioning and disinterested about life. We are all responsible for the world.

    Posted by: Anonymous | 8 years ago | Reply
  • Hi, am a student researching

    Hi, am a student researching about the growing obesity trend and was redirected here from wikipedia for a list of 20 substances or functional groups classified as obesogen, yet there are only 16. What is up with that?

    Posted by: Anonymous | 7 years ago | Reply
  • We have described only some

    We have described only some of the chemicals in the article. This is a developing field of research and more and more chemicals are being added to the list. For example a January study links tributyltin used in PVC and obesity.

    Posted by: Vibha Varshney | 4 years ago | Reply
  • The aftereffects of these

    The aftereffects of these chemicals in human body has to be seriously considered and its widespread use has to be restricted. Nowadays, a lot of people are suffering from obesity and thereby prone to many serious health hazards. So strict measures has to be adapted in an emergency mode.

    Posted by: Anonymous | 7 years ago | Reply
  • This is to be considered in

    This is to be considered in serious! Now people, especially IT professionals depend on fast and readymade foods due to their busy works! These readymade foods are prepared by adding several chemicals which has got several bad effects on our body! People are taking these foods without knowing the dangerous! We should aware them about the bad effects of readymade and fast foods!

    Posted by: Anonymous | 6 years ago | Reply
  • Some very interesting weight

    Some very interesting weight loss stories you mentioned there.

    Posted by: Anonymous | 6 years ago | Reply