Most of us at some point in our lives have tried something to lose weight. So we can relate to Monica Fair.

“I’ve always had this 12 to 15 pounds that I couldn't get rid of," said Fair, 47, who has experimented with trendy exercise programs and fad diets to no avail.

“I never could lose the weight,” said Fair. “As a matter of fact, I would gain muscle which would push the fat out and make me look bigger."

It turns out the answer may be on the inside.

"We're looking at genes that are responsible for your body composition,” said Kurt Johnsen, co-founder of a Dallas-based company called Simplified Genetics.

He’s a Kung Fu master, founder of American Power Yoga, and overall a pretty fit guy with a passion for helping others get healthy, too.

“I'm not a doctor, I'm not a scientist,” said Johnsen, who sat down with WFAA at Plum Yoga, along Dallas’ popular stretch of Lower Greenville. “I want to make sure what we do makes a difference."

Since 2012, Johnsen says his company has tested the DNA of 11,000 people, analyzing genes to match you with the best type of workout, diet, and vitamins for your body.

“This is the most revolutionary thing I have seen in over 35 years," said Leisa Hart, the blonde bombshell behind Buns of Steel. Now she’s 49, a mom, and still a beautiful fitness trainer.

“This is my job! I'm in good shape,” said Hart, admitting that there is a side of her that the public didn't see.

“Working out that often and that intensely -- my face would be red, my head pounding. I would have to take a nap many times throughout the week,” she recalled. “That was my body screaming at me saying -- please just slow down! You're not supposed to work out that hard that often."

Then Hart got genetic testing, which is really just a simple cheek swab. The swab is sent to a lab in Louisiana where your DNA is extracted and prepared for analysis. Results are put through algorithms that generate specific recommendations for you.

“I found out that when I was working out intensely, I was working out at much too high of a heart rate and I was working out for too long of a duration,” said Hart.

Based on her results, she actually needed to do less.

To the eye, 53-year-old Rosanne Lewis is similar to Hart. But her genetic makeup is completely different.

“I stopped eating all this bread… because I thought it wasn't very good for me. I started having nuts instead or I would eat cheese -- things I thought were healthier-- and I gained four pounds."

Lewis’ results showed she can get away with mostly low intensity exercise. But this type of DNA analysis goes deeper: identifying your idea diet. The bread-lover, Lewis, is more sensitive to fats than carbohydrates, meaning she can eat her bread and do yoga in peace.

“I know now for the rest of my life what I'm supposed to do,” said Lewis.

With people putting a lot of stock -- and money -- into these tests, we wanted to get a doctor’s take on them.

“This is the start, at the very least, of something very interesting,” said Dr. Leslie Cler, chief medical officer of Methodist Dallas Medical Center.

Dr. Cler told WFAA that this type of genetics testing has been on the market -- offered directly to consumers -- for a decade, but still is “in its infancy.”

Further, according to Cler, while different companies may get you the same results, their recommendations are open to interpretation.

“I don't think these tests are recommending anything dangerous to the patients -- not at all,” said Cler. “But as a doctor, if you came to see me and you said, ‘I heard about this test, if I get it do you think that I'd be likely to lose weight?’ The answer is -- I don't know."

Fair enough. But losing weight isn't always the goal. Remember Hart -- who scaled back on her workouts since getting her results?

“I feel so much better,” said Hart. “I feel like I could actually do more but I don't have to.”

Then there’s Fair, who went from a size 10 to a size 6 after putting her results to use. She added fish to her vegetarian diet, and now incorporates a blend of low-and-high intensity workouts.

“It was life-changing to be able to actually get to my goal," Fair said.

But what works for Fair won’t work for everyone. Makes perfect sense – if it boils down to DNA.

On Tuesday morning Sonia Azad, Ron Corning, and Alexa Conomos got their tests back -- see their results below!

Medical Study 1 by wfaachannel8 on Scribd

Medical Study 2 by wfaachannel8 on Scribd