Published: Nov 11, 2013 4:34 PM EST
Updated: Nov 11, 2013 11:13 PM EST

ESTERO, Fla. - It's the age-old question: what makes us fat? Many would say unhealthy eating habits and not enough exercise. We investigate a growing theory that what's making us obese, is really in our cells.

When it comes to losing weight, most doctors say stick to the basics: eat nutritious food, and burn more calories than you consume. But there's a growing population that believes the root of the world's growing obesity problem has to do with chemicals and toxins in our foods and environment.

Two Southwest Florida women we met said they spent years asking the same burning question: why can't I lose weight?

"I lose it and I gain it. I lose it and i gain it. That's a typical complaint," said Dr. Teresa Sievers in Estero.

She says the answer doesn't always come down to diet and exercise. She looks at patients' hormone balance, food allergies and toxins their bodies absorb from the environment and products they use.

By focusing on what's going on inside and outside of their bodies, the women tell us they finally dropped the weight and kept it off.

"Beauty products-- our skin is our largest organ in our body... and they are putting chemicals in their body without knowing it," explained Dr. Sievers. "nonstick cookware, nonstick bottles, those mimic estrogen in women and they can definitely cause imbalance. And any time you have imbalance, you're going to get symptoms."

There are chemicals in products we use everyday. According to the FDA, hairspray, shampoo, plastic flooring and walls sometimes contain chemicals called phthalates. Researchers at Mount Sinai Medical Center in New York found a link between exposure to phthalates and obesity in young children.

There are also chemicals in our foods. On the website, What's-on-my-food-dot org, you can search a list of foods and find information on pesticide residues found by the USDA. For example, thin-skinned apples, blueberries and strawberries contain some of the highest levels while oranges, bananas and pineapples, fruits that have thicker skin, have lower levels.

In 2006, Bruce Blumberg, a developmental biologist at the University of California, Irvine coined the term "obesogen." His and other studies suggest these endocrine-disrupting chemicals can lower your ability to burn fat while helping fat cells work more effectively.

The concept caught the White House's attention. In a report to the President, the White House task force on childhood obesity said fetal and infant exposure to "obesogens" may cause more weight gain per food consumed and possibly less weight loss per amount of energy expended with effects lasting throughout life. They recommended federal and state agencies to research the effects of the chemicals.

Dr. David Blyweiss is the Chief Medical Officer at Cell Science Systems in Deerfield Beach. Inside their lab, they analyze results of the "Antigen Leukocyte Antibody Test," or "ALCAT" which tests how people's cells react to hundreds of different foods, chemicals, molds and botanicals. He says more people than ever are calling, looking for answers.

"It is the food that we eat that is causing it. Remember, the food we eat is not most of the food we used to eat. Wheat today is not the wheat of 1960," said Dr. Blyweiss. "We've modified mother nature to our ease and it's biting us back."

This test may not be the answer for everyone. At this point, some medical professionals and insurance companies claim there's not enough evidence to support it. So the best thing you can do is meet with your doctor.