Obesity is a global public health challenge influenced not only by diet and lifestyle, but also by environmental and pharmaceutical chemicals that may disrupt metabolic balance and fat storage.
Using the zebrafish obesogenic test (ZOT), this study identified five compounds — amiodarone, dibutyl phthalate (DBP), rosiglitazone, tributyltin (TBT) and triclosan (TCS) — that induced a “thrifty phenotype”, a metabolic state that promotes fat retention during short-term fasting.
The study showed that the obesogenic effects of these compounds were independent of reduced physical activity or food intake. For example, TBT showed the strongest obesogenic potential without affecting locomotor activity, while diazepam reduced locomotion but showed no obesogenic effect.
The findings suggest that some environmental contaminants and pharmaceuticals may promote obesity by disrupting energy metabolism and increasing resistance to fat loss, highlighting a potential role of chemical exposure in the obesity pandemic.
The study supports the inclusion of metabolic and endocrine-disrupting effects, including chemically induced “thrifty phenotypes”, in obesity-related hazard assessment and highlights the value of integrating locomotor and metabolic endpoints in chemical testing strategies.
Obesity is a global pandemic that affects people of all ages. While behavioral, nutritional, and socioeconomic factors all contribute to weight gain, other factors in our immediate environment play an insidious role in the prevalence of obesity. Exposure to environmental and pharmaceutical compounds can be a contributing factor to increased weight gain. Using the zebrafish obesogenic test, our study demonstrates that amiodarone, dibutyl phthalate, rosiglitazone, tributyltin, and triclosan induce a thrifty phenotype under short-term fasting conditions. Diazepam significantly reduces locomotion without exhibiting any obesogenic effect, whereas tributyltin, which has the highest obesogenic potential among the tested compounds, has no effect on locomotion. The obesogen-induced resistance to fat loss is not correlated to inhibition of physical activity and a corresponding reduction in energy expenditure nor to food consumption. Primary prevention measures to fight against the obesity pandemic may include reducing exposure to obesogens that can induce a thrifty phenotype.
