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Obesity and Diabetes – a chemical link?


It is a commonly held view that obesity is all to do with too many calories taken in and too few expended in exercise, with a genetic predisposition in some individuals.

However, research suggests that exposure to certain manmade chemicals in our environment can play an important role in the development of obesity. While obesity is a known risk factor for diabetes, evidence is growing that chemical exposures are also implicated in diabetes. The human population is exposed to these suspect chemicals on a daily basis, mostly via food and consumer products.

We examine this research in our report & leaflet on Obesity & Diabetes.

CHEM Trust takes the view that given the current epidemics of obesity and diabetes, there is urgent need for action to reduce exposures to many chemicals implicated in these diseases.


The evidence that chemical exposures can affect weight gain in animals is compelling.

The term “environmental obesogens” refers to man-made chemicals that can disrupt normal controls over the formation of fat and energy balance. Chemicals implicated in causing weight gain have been identified both in experiments on animals and in cell-based studies, and include a variety of chemicals with diverse physical and chemical properties such as persistent organic pollutants (POPs – e.g., dioxins, polychlorinated biphenyls (PCBs) and certain organochlorine pesticides (OCPs), perfluorinated chemicals (PFCs) and brominated flame retardants (BFRs)), bisphenol A (BPA), organotins, diethylstilbestrol (DES), phthalates, organophosphate pesticides, lead, pre-natal nicotine exposure, diesel exhaust and some antipsychotic drugs.

It is therefore likely that there are other chemicals in the environment that increase the risk of obesity, which have yet to be recognised.


Type 2 diabetes is characterised by the body becoming more resistant to the action of the hormone insulin (which is secreted by the pancreas and works to balance the body’s glucose levels) and pancreatic-cell insufficiency. It is particularly alarming that the incidence of Type 2 diabetes is increasing in young people as well as in the older generations.

Type 1 diabetes is due to an immune attack on insulin-producing cells in the pancreas; it is characterised by low or absent endogenous insulin and has a peak age of onset during childhood.

While some researchers have tentatively suggested that both Type 1 and Type 2 may represent a spectrum of disease, the CHEM Trust report focuses on the role of environmental chemicals in Type 2 diabetes.  This is because little information is available on the relationship between human contamination with chemicals and the risk of Type 1 diabetes.

Possible candidate environmental diabetogenic agents include POPs (such as dioxins, PCBs, some organochlorine pesticides and some brominated flame retardants), arsenic, BPA, some phthalates, organotins and organophosphate and carbamate pesticides.

It should be noted that diabetes itself has not been caused in animals exposed to these chemicals in laboratory studies, but metabolic disruption closely related to the pathogenesis of Type 2 diabetes has been reported for many chemicals.


The increase in obesity and diabetes is of great public health, social and economic concern worldwide:

  • In England, by 1993 some 58% of men and 49% of women were overweight or obese, but by 2011, this had risen to a staggering 65% of men and 58% of women.
  • Around 3 in 10 boys and girls aged 2-15 were overweight or obese in England in 2011.
  • Diabetes in the UK has more than doubled since 1996 from 1.4 to 2.9 million people to reach a figure of 1 in 20 people affected.
  • In the UK, the NHS spent £1Million per hour on diabetes in 2008, which equates to £9 billion/year or 10% of NHS spending. A similar spending pattern is true for the USA and many other EU nations eg Belgium 7%, Denmark 7%, Italy 6%, Spain 6% and Finland 11%.
  • The estimated number of adults living with diabetes has soared to 366 million worldwide, representing 8.3% of the global adult population.  This number is projected to increase to 552 million people by 2030, or 9.9% of adults, which equates to approximately three more people with diabetes every 10 seconds.

The report notes that obesity represents a potential threat to the continued increase in life expectancy that has been achieved by medical and public health

Given the current epidemics of obesity and diabetes, there is urgent need for action to reduce exposures to the many chemicals implicated in diseases.

Read the report & leaflet on Obesity & Diabetes.

View list of diabetes organisations and charities