Are Heavy Metals Making Us Fat? Part 1

Every year more and more people around the world struggle with weight gain. While poor diet and less activity is a key part of this, many of those individuals are striving to eat well, stay active and prioritize their health. The problem is, it doesn’t seem to be working. So is there another factor at work that we are overlooking? Is there something that is part of our modern lifestyle pervasive enough to affect each and every one of us but less obvious than what is on our plate?

Coinciding with the rise of weight issues globally has been the steady increase of plastics, chemicals, heavy metals and other toxins in our daily environment. From our plastic coffee lids to our hand sanitizers and the air we breathe – it is impossible to leave your house without being exposed to toxins that are known health disruptors. While many of us may link heavy metals to fertility issues or fatigue, could they in fact be to blame for our weight complaints too?

Heavy metals, such as mercury, lead, arsenic and cadmium, are metallic elements that are highly toxic and impair health. Although they can be from natural sources, like volcanic eruptions, the majority of heavy metals in our environment are a result of industrial waste or agricultural chemicals like pesticides. As we pollute our environment, these pollutants enter our food, water, air, and eventually our bodies. 

So how does this translate to weight? Studies have shown that heavy metal exposure is linked to a wide range of health conditions including metabolism and weight. In 2018, an analysis of 9,537 adult samples showed that exposure to 18 different heavy metals correlated with several markers of weight gain – body mass index (BMI), skinfold thickness, total body fat, and obesity-related conditions like diabetes.(1) A study from China also showed that blood lead levels correlated with a higher BMI and risk of obesity in women but not men.(2) Other heavy metals like cadmium have even been shown to ramp up fat production at a cellular level (but more on this in Part 2!).(3)

The effect of heavy metals on weight is so strong that in some cases, high exposure during pregnancy can increase the risk of the child developing obesity later in life. One study on lead revealed, “Children whose mothers had red blood cell lead levels of 5.0 mcg/dL or greater (16%) had 65% greater odds of being overweight or obese compared with children whose mothers’ lead level was less than 2 mcg/dL, after adjustment.” (4, 5) A 2020 study was even able to correlate ambient air pollution exposure to obesity.(6)

There is much we are still learning about how heavy metals affect weight. Research shows us that not all heavy metals have the same effects and results can differ among age groups, gender, toxicity levels and more. If you suspect heavy metals may be interfering with your health, the best first step is to test your levels with a simple hair test as this will show you how much is being stored in the body.

Continue on to ‘Are Heavy Metals Making Us Fat? Part 2’ to uncover the mechanisms behind how these insidious heavy metals affect our metabolism and weight.


  1. Wang X, Mukherjee B, Park SK. Associations of cumulative exposure to heavy metal mixtures with obesity and its comorbidities among U.S. adults in NHANES 2003-2014. Environ Int. 2018;121(Pt 1):683-694. doi:10.1016/j.envint.2018.09.035
  2. Wang N, Chen C, Nie X, et al. Blood lead level and its association with body mass index and obesity in China – Results from SPECT-China study. Sci Rep. 2015;5:18299. Published 2015 Dec 14. doi:10.1038/srep18299
  3. Planchart A, Green A, Hoyo C, Mattingly CJ. Heavy Metal Exposure and Metabolic Syndrome: Evidence from Human and Model System Studies. Curr Environ Health Rep. 2018;5(1):110-124. doi:10.1007/s40572-018-0182-3
  4. Haelle, T. High maternal lead levels linked to children’s obesity. Ob Gyn News. 2019;10: 209286
  5. Wang G, DiBari J, Bind E, et al. Association Between Maternal Exposure to Lead, Maternal Folate Status, and Intergenerational Risk of Childhood Overweight and Obesity. JAMA Netw Open. 2019;2(10):e1912343. doi:10.1001/jamanetworkopen.2019.12343
  6. Xiaotian Liu, Runqi Tu, Dou Qiao, et al.  Association between long-term exposure to ambient air pollution and obesity in a Chinese rural population: The Henan Rural Cohort Study. Environmental Pollution. 2020;260:114077.

Rachel Erwin, Nutritionist & Content Writer

Rachel is a Nutritionist with a BSc in Biology and Global Health from the University of Toronto, and a Postgraduate Diploma in Human Nutrition from the University of Ulster. She has counselled and educated clients in Hong Kong, whose health goals ranged from weight loss to detox and hormone balancing. Her love of writing led her to complete ‘Writing in the Sciences’, offered by Stanford University, and since then she has contributed several evidence-based health articles to various publications.

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