Weight Gain and Chemicals: Science Hones in on the Connection

It was back in the late 1980’s when CFL’s founder began examining the link between certain synthetic and industrialized chemicals and weight gain. It would take another two decades before a handful of researchers would identify what they called “obesogens“–synthetic chemicals that appeared to alter the body’s metabolism, triggering weight gain and obesity.  Following yet another decade beyond that, and what is now evolved into an epidemic of overweight* and obese* people (and their pets and even diet-controlled lab animals**) not just in the U.S., but around the globe, a growing number of scientists are beginning to take the idea that certain synthetic and industrialized chemicals in our food, products and environment may, in fact, be at least partly responsible…

“Chemicals ingested on Tuesday might promote more fat retention on Wednesday”

“We are, of course, surrounded by industrial chemicals. According to Frederick vom Saal, professor of biological sciences at the University of Missouri, an organic compound called bisphenol-A (or BPA) that is used in many household plastics has the property of altering fat regulation in lab animals. And a recent study by Leonardo Trasande and colleagues at the New York University School of Medicine with a sample size of 2,838 American children and teens found that, for the majority, those with the highest levels of BPA in their urine were five times more likely to be obese than were those with the lowest levels.

BPA has been used so widely — in everything from children’s sippy cups to the aluminium in fizzy drink cans — that almost all residents of developed nations have traces of it in their pee. This is not to say that BPA is unique. In any developed or developing nation there are many compounds in the food chain that seem, at the very least, to be worth studying as possible ‘obesogens’ helping to tip the body’s metabolism towards obesity. For example, a study by the Environmental Working Group of the umbilical cords of 10 babies born in US hospitals in 2004 found 287 different industrial chemicals in their blood. Beatrice Golomb, professor of medicine at the University of California, San Diego, has proposed a long list of candidates — all chemicals that, she has written, disrupt the normal process of energy storage and use in cells. Her suspects include heavy metals in the food supply, chemicals in sunscreens, cleaning products, detergents, cosmetics and the fire retardants that infuse bedclothes and pajamas.  (source)

Chemicals and metals might promote obesity in the short term by altering the way that energy is made and stored within cells, or by changing the signals in the fat-storage process so that the body makes more fat cells, or larger fat cells. They could also affect the hormones that spur or tamp down the appetite. In other words, chemicals ingested on Tuesday might promote more fat retention on Wednesday. (source)

And there are other possible mechanisms that may be disrupted by certain synthetic and industrialized chemicals in our food, products and environment…

“Dr. Bruce Blumberg, professor of developmental and cell biology at the University of California, Irvine, has found that pregnant mice exposed to organotins (tin-based chemical compounds that are used in a wide variety of industries) will have heavier offspring than mice in the same lab who were not so exposed. In other words, the chemicals might be changing the signal that the developing fetus uses to set its metabolism. More disturbingly, there is evidence that this ‘fetal programming’ could last more than one generation. A good predictor of your birth weight, for instance, is your mother’s weight at her birth.” (source)


Assuming there is a very real possibility that certain synthetic and industrialized chemicals in our food (as well as personal care, household products and general environment) are altering metabolic processes and triggering weight gain in susceptible individuals, the key is to avoid those substances to the greatest extent this is possible.  When it comes to food, this means avoid eating ultra-processed foods that are mostly comprised of synthetic and industrialized chemical additives, and minimize processed foods that have been exposed to known obesogens like BPA and its evil twin, so-called “BPA-Free” BPS where these chemicals can migrate or leach into food and drinks through the food containers.

The easiest ways to avoid (or at least minimize) exposure to unwanted chemical additives in your food is to prepare your own meals, snacks and drinks using clean, natural, whole ingredients with a minimal amount of processing and additives. 


*Overweight/excess body weight is defined as a Body Mass Index (BMI) of 25 or above, and obesity is defined as having a BMI of 30 or above.

**”It isn’t hard to imagine that people who are eating more themselves are giving more to their spoiled pets, or leaving sweeter, fattier garbage for street cats and rodents. But such results do NOT explain why the weight gain is also occurring in species that human beings don’t pamper, such as animals in labs, whose diets are strictly controlled. In fact, lab animals’ lives are so precisely watched and measured that the researchers can rule out accidental human influence: records show those creatures gained weight over decades without any significant change in their diet or activities. 

“Reports of unexplained rise in the average weight of lab animals, was verified consistent across many species. Other species gaining weight: laboratory marmosets, macaques, chimpanzees, vervet monkeys and mice, as well as domestic dogs, domestic cats, and domestic and feral rats from both rural and urban areas. Researchers examined records on those eight species and found that average weight for every species had increased over the past 20 years. The marmosets gained an average of nine per cent per decade. Lab mice gained about 11 per cent per decade. Chimps, for some reason, are doing especially badly: their average body weight had risen 35 per cent per decade.  In virtually every population of animals the scientists looked at there was the same upward trend of weight gain.” (source)