Understanding Obesogens and the Obesity Epidemic

the other pandemic that's changing our world
obesity natural diet healthy
© Depositphotos / VadimVesenin

Two things just about everybody is thinking about these days: pandemics and food. Perhaps one of the unifying elements of the COVID-19 pandemic is a greater appreciation of the value of food. Suddenly everybody is cooking at home, using ingredients they have on hand - basically living more like our great-grandparents did. As strange as these times have been, it is perhaps the first time in a long while where our lives may look recognizable to our ancestors, at least when it comes to our daily meals.

My grandma grew up during the depression. She would tell stories of what food was like in their house when she was a child - the meals of fresh-baked bread, fresh vegetables, and eggs or meat (if they had any). They grew most of what they ate, and occasional treats of cream or meat came from her father’s congregation or through trade. Meals were simple, and just about everything was local and free of pesticides because that’s just the way food was back then. Kids ate what was served or they went hungry. Nutrition wasn’t even a topic of discussion, yet kids were still nourished, were rarely overweight, and didn’t have type-2 diabetes or known food allergies. What happened?


“Obesity is a worldwide pandemic in adults as well as children,” say scientists who examined studies involving more than 68 million people worldwide where they found that at least 1.9 billion adults were overweight, and approximately 650 million adults and 107.7 million children were obese.1 And in some countries, children were more likely to be obese than adults. This pandemic is deadly, accounting for 4 million deaths globally each year. And it’s not just the most obese who are at risk: 40 percent of those deaths occurred in people who fell into the category of “overweight.”

According to the World Health Organization, a person’s status as overweight or obese is roughly defined by where they rank on the Body Mass Index chart. BMI is determined by weight (in kilos) divided by height (in metres) squared. A result of 25 or more places a person in the overweight range, while 30 or more is considered obese. However, BMI as a health metric has come under scrutiny for being too simplistic since it doesn’t distinguish muscle mass from body fat, or take biological sex, race, or ethnicity (it was designed with Belgian men in mind) into consideration - factors that are nonetheless still frequently ignored by clinicians.

We know it’s a problem: in the U.S., obesity has tripled since the 1960s, from 13.4 to 42.4 percent in 2018,2 and in Canada it has risen from 14 percent in 1978 to 26.8 percent in 2018. Perhaps more worrying though is that when the statistics combine both those who are obese with those who are overweight, the percentage skyrockets for both countries ranging between 63.1 and 71.6 percent, or 2 out of 3.3,4

This alarming prevalence in those defined as overweight or obese ironically comes at a time when there has also been a massive campaign for nutrition awareness. We now know so much more than we used to about how our bodies work and the importance of diet and exercise, and yet two-thirds of us are overweight to some degree.

According to the data compiled in the review, “Environmental Obesogens: Mechanisms and Controversies”, part of the answer lies in the fact that healthcare providers and experts have a far too simplistic approach to what makes people overweight, specifically pointing to the standard recommendation of “managing diet and increasing exercise,” as being “myopic.” They point out studies that demonstrate “that exercise is consistently linked with increased fat mass in the long term”1—the exact opposite of what we’ve been told for years.

One of the largest such studies, the National Health and Nutrition Examination Survey,  analyzed groups of men and women between 1988 and 2006. They found that while both sexes increased “leisure time physical activity” (by 47 percent in males and 120 percent in females), that for an equivalent amount of caloric and macronutrient intake, average adult BMI was up to 2.3 kg/m2 higher in 2006 than in 1988.5 So, while the takeaway of the researchers is not for people to stop exercising or to eat whatever they want, it is rather to recognize that the study does “cast serious doubt on the sufficiency of the simplistic energy balance model of obesity and strongly implicate the importance of other risk factors in obesity.” In other words, obesity is complicated and the overly simplified “eat less, exercise more” paradigm is not enough for many, or even most, people.

healthy natural diet obesogens
© Can Stock Photo Inc. / yulka3ice


The advent of epigenetics, the study of environmental factors which turn genes “on” or “off”, thus determining how genes are expressed without changing a person’s fundamental DNA, has added a new dimension to the question of how much is determined by genetics and how much is environmental. Could obesity be linked to what happened while in the womb, or even perhaps, what happened to our ancestors long before we were born?

Developmental Origins of Health and Disease (DOHaD) research examines how the conditions encountered by a fetus in the mother’s womb, as well as post-birth, shape the wiring of the baby’s brain, the functioning of the organs, and metabolism, and how these conditions lay the foundation of the immune system. Dr. David Barker began this field of science three decades ago with his research linking low birth weights to chronic diseases in adulthood. Extensive research has shown that “low birthweight is associated with an increased risk of non-communicable diseases (NCDs) later in life, including diabetes, hypertension, cardiovascular disease, and neurological disorders.” Not only limited to newborn health and later disease risk, the negative effects of low birth weight can be transmitted across generations, even in the absence of other future exposures.6

Obese mothers, especially those obese before pregnancy7 and during the first trimester, are more likely to have babies that are born early, underweight, and that go on to be obese and to develop chronic health disease, such as diabetes, later in life.8 In the most extreme situations, obesity can also lead to pre-term births. The largest study looking at this showed obesity was linked with a “substantial increase in risk” of delivery before 28 weeks of pregnancy for first-time mothers and an increased risk for those having their second or later children.

Some scientists speculate that undernourished babies are born “hungry,” as if their metabolism thinks it was born into a world of scarcity. The cells of the mother may withhold calories from the fetus who becomes metabolically efficient at storing fats and hoarding calories and grows up metabolically to do the same. This hunger they experience in the womb is not necessarily about the quantity of food consumed by the mother, but rather the quality and whether it is affected by pesticide contamination, heavy metals, growth hormones, or other toxins. Thus, a person can be both undernourished and obese.

Nutrients flow across generations

While females born to obese mothers are more likely to be obese themselves, and birth weight of donor embryos has been shown to correlate with the surrogate and not with the biological mother, there’s more to it than just what happens in the womb. According to Better the Future, a movement to reduce chronic disease through nutrition and whose work is based on the science of DOHaD, Nutrients flow across generations…This means that a womans nutrition directly affects not only her own childs health, but her grandchilds health as well.” Lest one think this is all the responsibility of women, this flow isn’t entirely isolated to the nutrition of the mother. There have also been studies that indicate that males born to obese fathers are more likely to be obese and ones showing that a baby’s weight can be influenced by the health of the grandfather.

Among the most-cited research in this realm comes from the Överkalix study which examined an isolated community in Sweden from 1890 to 1995. This multi-generational, long-term study explored periods of extreme famine and other conditions of poor food supply to uncover whether they could influence the health of future generations with regards to mortality, obesity, and diabetes. Interestingly, some of the results showed risks passed down along the male sex lines. For instance, if a father started smoking early, it increased the chances of obesity in the son, but not the daughter. And similarly, a grandfather’s food availability during the “slow growth period” between ages 8 to 12 was associated with negative effects in the grandsons, but not the granddaughters.

A more recent Australian study had similar results, showing that the sons but not daughters, of obese fathers were at greater risk of developing obesity, metabolic disorders, and diabetes, even when eating the same foods as males whose fathers weren’t obese.9


It has only recently become common knowledge that our endocrine system, responsible for energy balance, fat deposition and distribution, and hormone regulation, can be interfered with by environmental chemicals, specifically those considered to be endocrine disrupting (EDCs). In 2006, Grün and Blumberg put forth the “obesogen hypothesis.” It proposed that EDCs in the form of obesity-promoting chemicals called obesogens were pervasive in the environment and could predispose individuals to obesity and related disorders.1Obesogens could both influence the formation of fat cells from stem cells (adipogenesis) and change metabolic rate, shift energy balance toward calorie storage, and affect the brain and other organs which participate in the processing of food.

From industrial chemical tributyltin (TBT) to fuels such as Jet Propellant 8,1 the list of known or suspected obesogens is long. In the study, “What Are We Putting in Our Food That Is Making Us Fat?” researchers list a myriad of hazardous food-specific obesogens, including antibiotics, hormones, heavy metals, dioxins, flame retardants, organophosphate pesticides (OPP), and phthalates. They also name a host of food additives generally recognized as safe, such as sodium benzoate, MSG, soy, and high fructose corn syrup as ingredients to be avoided.10 In the case of at least some of these obesogens, research suggests that their ability to influence weight gain can span through multiple generations even without direct exposure.11

Gut feeling: the healthy microbiome

At least some of the research into why North Americans are overweight and the role that obesogens play suggest that the health of the gut microbiome is an important factor in helping humans and animals mitigate the negative effects of obesogens. The microbiome refers to an ecological community of microorganisms - bacteria, fungi, viruses, archaea - that share our body space. Humans are made up of trillions of microbes. Indeed, human cells make up only 43 percent of the body’s total cell count! As research continues to explore the mystery of our gut makeup, we now know that at least some elements of our microbiome have co-evolved with us and are unique and essential to human health, especially in the functioning of our immune system and metabolism. It is believed that gut microbes can influence both the use of energy from our diet as well as the very genes that control energy expenditure and storage. While each microbiome is unique, aspects of it can be passed down to our children and their children through the birth process, affecting our epigenetics. Although there is still a lot we don’t understand about the microbiome and its role over generations, what is clear is that we can help ensure the best future microbiomes even before we conceive.

Researchers have found that microbiome diversity is diminishing, and much like the fine balance diversity plays in environmental ecosystems, our microbiome is dependent on a wide variety of inputs to ensure good health. While a likely culprit is our modern high fat, low-fibre, simple carbohydrate diet, research also brings into question our overuse of antibiotics and practice of using household antibacterial products, which are found nearly everywhere from hand soaps to the lining of our shoes. While antibiotics and even antibacterial products have their place, it’s important to recognize that to be in a state of complete health, a person needs all the elements of their microbiome living in harmony, including all human cells as well as bacteria and organisms that might be classified as viruses, parasites, or other as-yet-unidentified microbes. In short, we must have bacteria and other microbes, and lots of them, for human life to exist and we need them in good balance in order to be healthy.

natural healthy diet obesogens
© Can Stock Photo Inc. / Roxiller


With multi-generational impacts and environmental chemicals further complicating our already complicated relationship with food and weight, is there hope?

While the research shows that genetics and epigenetics play a role in obesity, body weight and environmental effects of obesogens are also heavily influenced by “stress, drugs, infections, diseases, and the microbiome,”1 making a healthy lifestyle and eating practices helpful both for you and your future generations.

Michael Pollan has cut through the confusion of contemporary dieting by advising that people focus on eating more like their ancestors: “Don’t eat anything your great-grandmother wouldn't recognize as food,” he says, warning against not just the sodas and chips, but also the go-gurts, power bars, protein shakes, and all the other over-marketed “food products” as well.

What if we were to take this advice a bit further and live a bit more like our great-grandma too? Science backs this up. Not only does participation in real-time social exchanges (a fundamental source of entertainment before technology took over that role) make people happier, it may also lower the risk of obesity, making it good for your physical health too.12,13 And in terms of outdoor activity, including a 30-minute walk in your daily routine can be more beneficial than joining a gym for waistlines and overall weight loss and when done outside there are added benefits to mental and physical health as well.14

Trading in screen time for outdoor time, like gardening, birdwatching, or hiking, has many proven benefits, not the least of which is the positive effect on the microbiome of being outdoors. Even less active hobbies such as photography, painting, writing, traveling, cooking, knitting, or sewing have been shown to lower blood pressure, improve mental health, and otherwise positively influence one’s ability to manage stress, thereby helping to regulate the negative effects of obesogens. And while we’re on the subject of screen time, ditch the technology before bed. Not only does that mean more, better quality sleep, but it too may help with weight loss, as there is a lot of research linking sleep disruptions and disturbances to obesity.15

Small Steps for Big Benefits

Choosing a healthy diet doesn’t have to be daunting. In fact, you probably already know more than enough to get started. Eating and living more like your great-grandma automatically means reducing exposure to obesogens in food and water. The simplest way to do this is to minimally alter your diet by replacing processed foods with the less processed or minimally processed version of the same and replacing everything you consume or rub on your skin with an organic version.

Morning modifications

If breakfast consists of cereal with skim milk and coffee sweetened with a sugar alternative, a minimal alteration would be switching to an organic cereal with whole, organic milk, and organic coffee brewed with filtered water and sweetened with real organic sugar.

Why? Research has linked skim and low-fat milk consumption to weight gain (and infertility), suggesting these versions behave like an endocrine-disrupting chemical (the same reason to consider avoiding soy as well). Sugar alternatives such as saccharin and aspartame have been linked to changes in the gut microflora that result in obesity. Further, tap water and sometimes, especially bottled water, can have all sorts of obesogens in it.

Supper substitutions

If dinner is red meat or chicken salad, rice, and diet soda, you can find organic versions of all these components (and skip diet-anything). The refined salt can be replaced with sea salt, and organic spices are readily available.

Why? Conventional meat can be contaminated with obesogens. Conventionally raised beef has some of the highest trace amounts of growth hormone and steroids, and conventional chicken and farm-raised fish have some of the highest antibiotic residue. Conventionally grown vegetables can contain very high traces of pesticides such as OPP, and conventional rice is likely to be contaminated with pesticides and even arsenic. Diet soda consumption is even more significantly linked to obesity than its full-sugar alternative (although neither are great).

Clean slate

For personal care, go organic or EWG green-certified. Switch-out your shampoo and conditioner and skin moisturizer. Try an edible, organic oil like cocoa butter or almond oil in place of anything perfumed or petroleum-based.

Why? Your skin is extremely porous, and chemicals rubbed on your body can enter directly into your blood stream. Many proven obesogens are found in skin creams, perfumes, and other beauty care products.

Level-Up the larder

Once those simple switches have either become second nature or your pocketbook is suffering (organic versions of processed foods are notoriously costly!), it may be time to phase out certain foods altogether. Sodas, cereal, deep-fried foods, and commercial snacks can be replaced by cooking from scratch. The same goes for restaurant meals, which are expensive and less likely to contain the highest quality ingredients. When you cook more yourself, you can splurge on organic vegetables and healthy fatty foods like wild-caught fish and pastured, organic butter.

If you’re having trouble kicking the soda habit, homemade fermented beverages such as water kefir, ginger brew, or the ever-popular kombucha can be a great way to get probiotics and still get your soda fix. Probiotics and fermented foods like sauerkraut or kimchi can help re-introduce some of the more common strands of beneficial bacteria into the body.

Try skipping snack time altogether by ensuring each meal is substantial and balanced among nutrient groups, or at least better space your meals.

Why? Functional medicine nutritionists, including Margaret Floyd Barry of Eat Naked Now, believe that bodies are meant to go through healthy highs and lows of blood sugar during the day and when meals are replete with a balance of high-quality elements, the urge to snack is naturally reduced. When we don’t eat a balance of healthy fats, protein, and carbohydrates and opt for a diet of simple sugars instead, our blood sugar spikes higher and dips lower than it would otherwise, resulting in the urge to snack on goldfish crackers or indulge in afternoon caffeine. Eat more protein, healthy fats, and vegetables at each meal and then reach for a glass of filtered water between meals. Floyd Barry recommends adults go four hours between meals, and while kids aren’t likely to be able to go that long, ensure that snack time is loaded with healthy fats to keep the blood sugar levels working as they should.

Further, we must change our mindset about fats - our body needs them! The development and maintenance of our brain, skin, endocrine system, and weight are all dependent on high quality fats. They also promote satiation, allowing you to make it more comfortably to the next meal.

Understanding obesogens and their role in our health can empower us to invest in lifestyle changes and dietary habits that have incredible health benefits both for us and our descendants. It also makes it clear that a solution involves a societal demand for change. As our food supply becomes increasingly contaminated and our healthcare systems become taxed with dealing with the health consequences, perhaps we will see that obesity is a disease cultivated by poor regulation of chemicals, pesticides, and food additives, and directly linked to access and means. It would be nice to imagine a future where every child has unfettered access to foods that aren’t laced with chemicals likely to decrease their chance of thriving. Living through COVID-19 makes it clear that we are able to take dramatic actions when we have the will, and perhaps will convince us there is a way, no matter what pandemic we’re faced with.

You may also enjoy: Going Green: Organic Food on a BudgetChildhood Obesity Linked to Chemicals, and Olive Oil for a Healthy Weight

For further reading visit ecoparent.ca/EXTRAS/fall20.

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