TYLER (KYTX) - Crash diets, fasts, cleanses and miracle diet supplements often promote themselves as quick ways to drop big pounds, but at what cost? Health experts say these extreme measures aren't good ways to keep the weight off. Even worse, they can harm your health. In a Special Fit City report, find out how dieting can spiral out of control into dangerous dieting.

Dangerous dieting can eventually manifest itself into an eating disorder like anorexia or bulimia, sometimes both. A dietitian tells me it can start innocently with someone wanting to get healthy and lose a few pounds and for others, it's a way to control trauma in their lives. Before you know it, you're anything but healthy.

"When I was a teenager, for some reason I had it in my mind that I had to be a certain weight, a certain size," says Vicki Jowell.

Vicki Jowell spent much of her teens and twenties dangerously thin. "I was just missing meals, challenging myself each day to eat less and less. Just drinking water and a few crackers and trying to get through the day," says Vicki.

Vicki is a mom of four now and on a new journey of healthy eating, living and thoughts, but looking back... "I remember if I lost weight I felt good about myself. I felt in control, but that was very unhealthy and sometimes I was tired and weak," says Vicki.

Vicki works out with a trainer at Premier Fitness now and follows Weight Watchers, a realistic routine she can stick to, unlike her early struggles. "I tried it all, I think, diet shakes, diet drinks, diet pills, not eating, a combination of several different things," says Vicki.

"It is systemically dangerous. It effects your entire body. There is the malnutrition that occurs and when you are having malnutrition, you are not getting the vitamins and nutrition you need to function normally," says Sara Upson, Registered Dietitian at My Signature Nutrition.

Sara Upson is a registered dietitian at My Signature Nutrition who also works with clients struggling with eating disorders. "About 20-30% muscle mass can be lost from calorie restriction alone and depending on how much malnutrition you have, it can be even more than that. Additionally, there is dehydration, electrolyte imbalance and there are effects on the brain and also on the heart," says Sara.

Sara says the brain can actually decrease in size from malnutrition connected to dangerous dieting and you can shift your metabolic profile for the worse. "95% of all diets fail, meaning you will lose weight initially but once you stop, you will gain that weight back and what the literature shows is you don't just gain the weight you lost back, you gain back more weight than you lost. What happens is when you lose that weight, you also lose muscle mass," says Sara.

Vicki says to this day she's living with some of those repercussions, but she gets tremendous support from someone who can relate, her trainer Emily Dumelle. "In high school I didn't want to be the mess up kid. I wanted to get good grades. I wanted to please my parents," says Emily Dumelle.

Emily's struggles with grades in high school turned into something much more serious. "So, I started to weigh myself every day after I would workout and then before I knew it I was losing a pound a day. And if I didn't lose a pound, I would eat less," says Emily. And workout more.

That's on top of playing tennis in college, which left little time for friends or family.

"I felt out of control in my life, but I could control the scale through what I ate and how much I exercised, but it wasn't until I gave God control of my life that I started to get free in my mind and to start thinking healthy," says Emily.

Returning to healthy eating isn't always easy. That's where Sara and dietitians like her can help. "Help them listen to their body and get back to a healthy weight where they are able to maintain it by eating when they are hungry and stopping when they are full and eating all of the foods they enjoy," says Sara.

Vicki and Emily are no longer bound by that restriction mentality. They've found a healthy balance where food no longer controls their lives.

If any of this sounds familiar, Sara says early recognition is important. If you or someone you know is skipping meals, isolates themselves from others, or no longer loves the things they used to, those are red flags that dieting has turned dangerous. It can get to the point where they need 24- hour care to get medically stable.

When it comes to diet supplements, Sara says there is no evidence for them. The pills are only guaranteed by the manufacturer. The FDA does not oversee supplements like medications.

We have more information on dangerous dieting and eating more intuitively on the hot button.