By Brad from Fooduciary.com.
Environmental chemicals known as obesogens are found in many places, including pesticides used on conventional produce. They program our bodies to store fat and develop disease, and do so to such an extent that in theory a head of conventional romaine could actually cause more weight gain than a grass fed burger.
"Obesogens belong in the class of chemicals known as endocrine disruptors. This class of toxins simulates the effects of natural hormones and disrupts normal hormonal responses. In terms of weight gain, "chemical calories" may actually be more significant than the caloric value of those calories.
How do obesogens exert so much influence? One method is by disrupting the normal release of leptin, the hormone that tells the brain you're full. In addition, obesogens encourage the body to store fat by reprogramming cells to become fat cells, and they also contribute to insulin resistance. What’s more, they're inflammatory substances, producing oxidative stress, damage the body's energy source, mitochondria, which then has a cascade of negative after effects.
Certainly some people are more sensitive to these toxins than others, though some are highly susceptible. Obesogens can have significant effects on children in utero, causing the fetus to produce more fat cells and increasing the likelihood of childhood obesity.
With those types of concerns and possible outcomes, the big questions are where do these chemicals come from and how do you avoid them?
Meat and dairy are two major sources. Commercial meat production operations are permitted to use a variety of six hormones to promote growth in beef cattle or milk production in dairy cows. Studies have shown that people who eat hormone-treated beef have higher levels of foreign hormones in their blood and tissues, and one study with 10 universities as participants states a connection can be drawn from hormones found in dairy to the drastic rise of obesity rates.
Fish aren't off the hook either. The feed pellets given to farm-raised fish include antibiotics that are classified as obesogens, and the flesh of farm-raised fish have been found to have high levels of pesticide residue.
As mentioned, conventional produce is another large contributor. The sprays used on crops are estrogen mimickers and thyroid disruptors, both attributes that promote weight gain.
Sadly there’s more. BPA and other chemicals in plastic disrupt the endocrine system and increase the size of fat cells. Same goes for the pesticide residues, traces of pharmaceutical drugs, and other toxins in tap water. (The National Institutes of Health classifies tap water as a major source of endocrine disrupting chemicals.)
If you can't afford to buy everything organic, familiarize yourself with the Environmental Working Group's list of the Dirty Dozen, the most toxic conventional produce you should make it a priority to avoid."