One more mile. One fewer calorie. For people with anorexia, every step on the treadmill and every ignored hunger pang is a victory against the voice in their head telling them they're fat.
Anorexia is the third most common chronic illness among adolescents, according to the National Association of Anorexia Nervosa and Associated Disorders.
Unlike older generations, younger people have the Internet to turn to, for mental health resources or for motivation and strategy to stay thin.
Websites that encourage anorexia, often referred to as pro-ana sites, give tips to stave off hunger or to hide disorders from friends and family.
Eating food off a dark plate will reduce the amount of food consumed. Drink diet pop in large gulps, to fill up faster. Sit in a mall food court and watch heavy people eat. Drink ice water and take ice cold showers to burn more calories. Boil water and dissolve one or two bouillon cubes in it, to consume when you're hungry.
The sites often show pictures of very skinny people and of morbidly obese people to serve as inspiration or "thinspiration." They post statistics, listing current weights and goal weights, often under 100 pounds.
Anorexia nervosa is a potentially life-threatening mental illness, an eating disorder defined by the inability to maintain one's body weight within 15 percent of their ideal body weight, according to the National Alliance on Mental Illness.
It further defines the illness as people who have an intense fear of gaining weight, a distorted body image, denial of the severity of the illness and, in females, an absence of at least three menstrual cycles in a row.
Scientists believe anorexia is caused by a combination of genetic and environmental factors. Predominantly affecting adolescent girls and young women, it can occur at any age and also in boys and men, according to the alliance.
Obsessions manifest about food and weight. Excessive exercise is common.
The eating disorder may lead to brittle hair and nails, yellowed and dry skin and complaints of always feeling cold. But, the damage caused by anorexia can go deeper than aesthetics.
"The starvation experienced by persons with anorexia nervosa can cause damage to vital organs such as the heart, kidneys and brain," according to the National Alliance on Mental Illness. "Pulse rate and blood pressure drop, and people suffering from this illness may experience irregular heart rhythms or heart failure which can lead to death in certain situations ... In the worst-case scenario, people with anorexia can actually starve themselves to death. Anorexia nervosa has the highest mortality rate of any psychiatric illness, both due to the complications of malnutrition and the high rate of suicide in this population."
Recovery is possible through help from medical and mental professionals, through supervised weight management and individual, group and family therapy, according to the alliance.