PHOENIX, Arizona (CNN) -- Two years ago, Karen Daniel was wider around than she was tall.
"It's a lot harder to be fat than it is to work so hard at being fit," says Karen Daniel who has lost 175 pounds.
Weighing 375 pounds, the 45-year-old wife and mother had high blood pressure; her knees hurt and she was always hot. She felt fatigued and could barely breathe at the slightest exertion. Even the simplest things became a chore -- tying her shoes, crossing her legs, getting in and out of the car or trying to fit into a chair with arms.
"I wasn't living ... I was just existing," recalled Daniel.
She hadn't always struggled with her weight. Daniel said she started gaining weight at age 18 after moving out of her parents' home to live on her own. By the time she married her husband, Paul, at age 22, she weighed 225 pounds.
"Whenever something happened, I used food," said Daniel. "It was like my drug of choice was food. I never did drugs or alcohol. I was addicted to food."
Seven months after her wedding and another 50 pounds later, Daniel became pregnant with her first child. Instead of gaining weight during the pregnancy, she lost 75 pounds after a doctor warned her not to use it as an excuse to eat. But after her daughter Sarah was born, Daniel gained back all the weight she'd lost and then some.
Ten years later, she weighed 300 pounds and became pregnant with their second child, Mckenna. Again, she lost weight during the pregnancy, but with the stress of having another child and running her own business, she turned to food. By the time her youngest daughter was 10 years old, Daniel weighed 375 pounds.
"I ate all the time. ... I was stuffing my emotions, I was eating my emotions," said Daniel. "When I would finally get [Mckenna] to bed at night, I would stay up late and that was my time alone. I tried to de-stress and wind down and I'd watch TV and eat. It was mindless eating."
Mentally, something started to click and Daniel began to wonder how and why she had allowed her weight to spiral out of control. She said there was no "lightbulb" moment or wake-up call that made her realize she'd had enough. For her, there was a series of events that helped her finally realize she was tired of being morbidly obese. Watch Karen Daniel take flight to achieve a lifelong dream »
"I couldn't bend over to tie my shoes, get down on the ground or fit into chairs. Everything was hard," said Daniel. "You're constantly worried about fitting on the toilet or in the shower or visiting someone's house and [worrying] about breaking a chair. It affects every minute of your life and you don't realize it."
As fate would have it, she saw a TV commercial for exercise equipment that was being sold at a local gym. It was geared toward senior citizens, but Daniel saw it as a start. When she showed up to buy it, she met the gym's owner, Bill Crawford.
"He gave me some of his literature and told me if I needed anything or a jump-start to give him a call," said Daniel. See Daniel's before-and-after photos »
When Daniel got home, she told her sister, Jan, she was thinking about hiring Crawford as her personal trainer, but she was hesitant. Her sister asked if she would have to think twice about hiring a trainer if it were for her husband or daughters.
"She made me realize I was worth it as much as they were," said Daniel, whose fear of failure kept her from telling people outside her family about her plans to work out.
On September 15, 2006, Daniel showed up for her first training session. She was wearing a dress over her workout clothes because she refused to be seen in size 40W pants.
"When Karen first walked in the door, she weighed 375 pounds and she could barely make it from the car to the front door," recalled Crawford, founder of Basic Training in Phoenix, Arizona. "I knew that just making it to the front door of a fitness center was a big deal."
Before her first workout, Crawford took her measurements, but the tape measure wasn't long enough to fit around her hips. He needed seven more inches.
"I was 67 inches around on my butt and 65 inches tall. So I was two inches bigger around than I was tall," said Daniel, who had a body fat percentage of 54.60 percent. "I also couldn't fit on his scale or in some of his machines when I started."
Crawford and Daniel improvised and she made it through her first hourlong workout. She continued to train for one hour, three times a week and said even though she "hated every minute of it" she pushed herself.
"It was extremely hard, I'm not gonna lie," said Daniel. "I couldn't count down the minutes fast enough. It was something I did not enjoy -- I was so out of breath. I was sweaty, hot. But as soon as I stepped out that door, it was so worth it to me because I felt so much better about what I had accomplished. I knew I made it through one more workout. I knew it was getting me closer to where I wanted to be."
In addition to the one-on-one training sessions, Daniel modified her diet, eating more proteins and complex carbohydrates. She also eliminated bread and pasta and reduced her intake of sugar, salt and processed foods. If she craved something sweet, she ate a piece of fruit. She cooked with olive oil instead of butter.
Just short of her one-year anniversary, she had lost 102 pounds. Her daughters gave her a Tiffany bracelet and her sister, Jan, treated her to her first pedicure. Crawford, her trainer, celebrated her success with a reminder.
"I had her take two 50-pound dumbbells and walk out to the street and walk back," recalled Crawford. "When she got back she was exhausted and that's the kind of weight people have to carry when they're overweight like that."
On her one-year anniversary, Daniel had lost 114 pounds. By her two-year anniversary on September 15, 2008, she had lost 170 pounds. Now weighing around 200 pounds, she has gone from wearing a women's size 30 dress to a size 14 and she's gone from wearing a double-wide shoe to a medium width.
Since losing the weight, Daniel has celebrated many milestones she never would have achieved weighing nearly 400 pounds, such as attending sporting events with her family, white-water rafting, kayaking, flying on an airplane without buying two tickets or using a seatbelt extender or simply being able to look down and see her feet. She recently achieved one of her lifelong dreams: riding in a hot air balloon over the Arizona desert.
Today, she works out nine times a week -- doing cardio and weight training twice a day with Crawford on Monday, Wednesday and Friday. Then she does a mix of cardio and weight-resistance classes on Tuesday, Thursday and Saturday.
Even though she now enjoys working out, staying on track is a constant struggle. Daniel said losing weight has been the hardest thing she's ever done.
"Every minute of my life was about my weight. What I couldn't do. Things I couldn't accomplish," said Daniel, who admitted it was hard to get started. "It's a lot harder to be fat than it is to work so hard at being fit. Fit feels so good."
What's next for Daniel?
She wants to lose 35 to 40 more pounds before her 48th birthday and keep adding to the list of things she wants to do to make sure she savors every moment. Most of all, Daniel hopes to inspire others by sharing her weight-loss story on her Web site, www.ihavebones.com.
"I just wish they would take the first step, because it's so worth it. Your life is so much better than worrying about where you're going to sit and how you're going to sit. You can actually ... enjoy life!"
Matt Sloane contributed to this report.