While some adolescents struggle with eating too much and become overweight or obese, other youth overly-restrict their food intake through the use of dangerous and unhealthy dieting practices and fail to meet their bodies' minimum nutritional requirements. As surprising as it may seem, some youth also excessively exercise their bodies in an effort to control their weight. While exercise is generally considered a healthy activity, it can be misused when the body is not provided sufficient rest and recovery periods, or when caloric intake is inadequate to meet the demands of the physical activity. When teens use exercise as a way to "punish" themselves for food indulgences or weight gain, or become highly anxious when they are prevented from exercising (such as during an injury or illness), this can indicate a problem may be developing such as an eating disorder.
Typically, parents worry about their daughters using unhealthy dieting practices for weight control, but guys can also make unwise, weight-loss-inspired decisions that can be damaging to their body. Some teens just make poor nutrition choices because they don't understand how their bodies use calories as fuel, but some teens make intentional decisions to lower their weight, sometimes to dangerously low levels, using drastic and unhealthy methods.
When teens purposefully attempt to become underweight, it can have devastating effects on their bodies. Youth that do not consume enough calories, or fail to make the right food choices, will become tired, weak, and moody. Furthermore, an inadequate supply of fuel (calories) negatively affects brain functioning and so it will become even more difficult to make wise and healthy decisions, and more difficult to learn while at school. If adolescents continue to restrict food too much, and lose too much weight, it can cause permanent damage to the heart, bones, and other organs. In extreme situations where youth are significantly underweight, they can even die due to malnourishment.
Some teens attempt to control their weight by overly restricting their food intake, consuming far too few calories, either by skipping meals entirely, or by severely reducing the amount they eat at every meal. In fact, about 10.6% of high school youth reported not eating for 24 hours or more to manage their weight (Eaton, Kann, Kinchen, et al., 2010). Other youth will totally remove a particular type of food from their diet, such as carbohydrates or breads. Some even use radical fad diets that only allow certain foods or even only weird drink concoctions in order to "flush" the body. All of these choices can damage teens' health because their growing bodies need the right nutrients in the right amounts to work properly. Even mainstream diets can be unwise for youth because these programs base their food recommendations on the nutritional needs of adult bodies that have completed their growth and development.
Furthermore, adults typically have slower metabolisms and are less active so their caloric requirements are not the same as for growing adolescents. Besides misusing exercise and/or drastic reductions in caloric intake, there are other dangerous practices that some teens may use to control or reduce weight. For instance, some teens will use diuretics (water pills), diet pills, tobacco, or other drugs in an effort to control their weight. In a recent study about 5% of youth reported using diet pills, powders, or liquids not prescribed by a doctor to manage their weight (Eaton, Kann, Kinchen, et al., 2010). Beyond the risks of becoming underweight, these chemicals can cause other significant damage to teens' organs and overall health and may lead to addiction as in the case of nicotine in cigarettes, or amphetamines in certain diet pills.
Another dangerous practice is purging. Purging typically involves the use of self-induced vomiting or laxatives in an effort to rid the body of unwanted food, but excessive exercise is also considered a form of purging. Approximately 4% of youth reported using laxatives or vomiting to manage their weight (Eaton, Kann, Kinchen, et al., 2010). These behaviors are very risky and harmful to the body. For example, when youth repeatedly vomit to purge, the excess stomach acid can cause bleeding and ulcers in the esophagus and can cause tooth decay. Frequent purging is symptomatic of an eating disorder called Bulimia Nervosa.
Whether it is some unhealthy dieting scheme, frequently skipping meals, restricting certain food categories, using chemical or drugs, excessive exercising, vomiting, laxative use, or some combination of these unhealthy weight control behaviors, parents have reason to be concerned. These behaviors may signal that an eating disorder is developing. And while some youth who engage in these dangerous practices may be visibly underweight, other youth may show no outward symptoms and may engage in these dangerous practices in secret. If parents suspect their child already has a problem with unhealthy dieting practices and/or they notice their child becoming underweight, they should seek out help from their children's family doctor, pediatrician, and/or a behavioral health therapist. There are many possible signs that would indicate that a youth needs help including extreme, rapid, or sudden weight loss without another medical explanation; loss of menses (monthly menstrual period) for females; hair loss, the development of fine, baby-like body hair (lanugo), secretive eating or purging behaviors; obsessive or ritualistic eating habits (such as refusing to eat food unless it is cut in a precise exact manner, or eating foods in a precise and rigid order) frequent trips to the bathroom immediately after consuming a meal (to purge the meal), becoming highly anxious if unable to exercise, significant changes in mood, behavior, or sleeping patterns; or an excessive focus on weight and appearance that consumes the majority of youth time and attention, and prevents them from enjoying other activities or interests.
More information about these disorders can be found in the topic center on Eating Disorders.
To prevent youth who are concerned about their weight from using drastic means, caregivers should emphasize healthy lifestyles and educate their children about the best ways to care for their growing, changing bodies. Parents need to make sure their young adolescents understand how their bodies are changing during puberty, as this change can be difficult for youth and can make them extremely self-conscience about their bodies. For more information on this topic, see the Middle Childhood Article on Puberty. Moreover, caregivers should repeatedly educate their children about balanced eating and exercise practices. Caregivers should have open, honest conversations about eating and exercise and take opportunities to address youths' possible misconceptions about food, weight, and body image. Caregivers should also emphasize all of youths' positive attributes and encourage activities that youth can take pride in; such as sports, arts, academics, etc, as these activities encourage a positive self-image.