1. Anything that causes the gaining of weight; whether it be food, lack of exercise, or whatever it might be: Obesogens consist of any environmental triggers that cause obesity.
2. A chemical that leads to overweight by increasing the production and storage capacity of fat cells: Obesogens, a series of chemicals known as endocrine disruptors, imitate hormones and confuse the body and cause fat storage.

Many obesogens penetrate through the plastic containers into food and beverages, like plastic bottled water, or into canned foods. Agricultural chemicals sprayed on crops, or foam cushions, or plastics used to store food or water can all contain obesogens.