How thin is too thin?

Controversy began after an appearance to promote a new line of Victoria's Secret swimwear, where Swanepoel (seen below center) looked shockingly thin compared to her curvier counterparts Alessandra Ambrosio and Adriana Lima. Swanepoel claims she's happy and healthy, but her alarmingly tiny physique raises the question: How thin is too thin?

Be careful with your calories

We all know that in order to lose weight, we need to cut back on calories consumed, and that eating too much can lead to weight gain.

But to get some insight into eating disorders, what it means to be too thin and how best to lose weight the healthy way, SheKnows turned to sports dietitian Marie Spano, MS, RD, CSCS, CSSD.

Too little food can mean low metabolism and muscle loss

When we don't provide our bodies with enough calories, a few things can start to happen.

If a woman is consuming just a few hundred calories less than she burns off, she may not have any side effects beyond weight loss -- but if she keeps this up, over time her basal metabolic rate (the calories burned at rest) may slow down to adjust, Spano explains.

Further, if a woman doesn't consume enough total protein to maintain her muscle mass, some of the weight she loses will be muscle. "In the case of anorexia, part of the muscle mass that can be [negatively] affected is the heart," the sports dietician says. In women, low weight is also related to osteoporosis.

Healthy versus harmful weight loss

If someone like Candice Swanepoel -- who is already thin -- wanted to lose weight, Spano would first ask why she wants to lose weight, then discuss a healthy body-fat range and the effects that weight loss can have on muscle tissue.

Someone who is already thin who is still seeking to lose weight -- especially quickly -- may not be aware of the ramifications of that goal, and the damage that actually happens to the body when it goes for too long without enough fuel.

After discussing their reasons and hearing the client's perspective and perception of her body image, Spano might refer the woman to a mental health practitioner who focuses on body image, weight and eating issues.

"Eating disorders are complex and oftentimes are the result of life events or the desire to control one aspect of life when the rest of one's life is out of control," Spano says. "The role of a mental health professional cannot be underestimated."

Eating disorders explained

It remains to be seen whether or not Victoria's Secret stunner Swanepoel is actually healthy or if her relationship with food is skewed. But the fact remains that eating disorders exist, and women everywhere develop a distorted view of their body image and their relationship with food.

Eating disorders include anorexia, bulimia and the most prevalent, EDNOS (eating disorder not otherwise specified). EDNOS includes a variety of criteria for disorders related to eating that do not meet the specific criteria for anorexia or bulimia.

Healthy living and eating

When it comes to losing weight in a healthy manner, Spano says it totally depends on the person. To start, she encourages people to take up a physical activity or training program they enjoy. "Enjoy" is the key word: If you hate the gym, you are not going to go, so seek out other activities that you like so you'll stick with it.

Spano also works with clients to figure out why they eat (hunger, non-hunger reasons), what they eat and the best solution for them to lose weight.

Below are some of the sports dietician's tips for healthy weight loss and overall healthy living.

Tweak your relationship with food: If you struggle with how you view food and have body image issues, make peace with food. Unlike an alcoholic, who can give up alcohol and still live, we cannot give up food.

Eat like a European: Sit down, take your time and enjoy the eating experience rather than rushing through a meal and ending up unsatisfied later. The more you truly enjoy the experience of eating, the less likely you are to mindlessly snack later on.

Divide your plate: Fill half of your plate with fruits and/or vegetables at every meal. A quarter of your plate should be protein, the other quarter carbohydrates (ideally, whole grains) to ensure you're getting everything your body needs and that you're focusing on fresh, non-processed foods.

Get enough protein: Adults should have at least 20 grams of protein at every single meal – preferably 30, Spano says, who adds that one surefire way to lose muscle mass is to consume a low-protein diet.

Photo credit: WENN.com

More on dieting and eating disorders

Thin is not 'in'
Amenorrhea: Dieting to the extreme
Truth, lies and reality of anorexia and bulimia