(Muenzinger 1999) Also, some recent nutritional research dealing with the same amino acid tryptophan demonstrated the complexity of the biochemical interactions between chemicals in food and the so-called neurotransmitters and other substances produced by the body. A direct quote from a text dealing with this subject emphasizes how these interactions are related to stress: “If you eat protein either alone or with a carbohydrate and your brain is rapidly using up its supply of dopamine or norepinephrine it will use tyrosine supplied by the protein to manufacture more of these two neurotransmitters. When that happens, you'll find yourself responding more quickly and with greater accuracy to mental challenges. You will be more alert, more motivated, more mentally energetic and "up." If you eat carbohydrates alone, without protein, more tryptophan will be made available to your brain, which will use it to make more serotonin. As a result, you will feel less stressed, less anxious, more focused and relaxed.” (Muenzinger 1999) In addition to sufficient amounts of nutrients, we are admonished to include in our diets adequate amounts of nonnutritional substances as well, substances such as fiber and water, for example. At the same time, however, we are encouraged to avoid excessive consumption of other nonnutritional substances, such as alcohol and caffeine. One obvious variable often overlooked in this public relations effort is the fact that individuals are idiosyncratic in terms of their metabolisms, biochemistries, and physiologies, as well as their characteristic life-styles. Also, as discussed above on the subject of general health status as a moderator variable, age, sex, educational achievement level, and socioeconomic status are involved in the problem of optimizing the relationship between nutrition and health maintenance and the part this interaction plays in the prevention of excessive stress. Although the findings in the literature relating nutrition to stress remain somewhat equivocal (the relationship between cholesterol and coronary heart disease, for example), there is nothing in the stress literature that contraindicates the general proposition that taking all possible steps, including proper nutrition, to sustain optimal physical health will assist in controlling stress level and, in turn, will greatly increase one's overall physical state.
For decades it has been accepted that good nutrition has a positive effect on a child's ability to learn and that skipping a meal, especially breakfast, can have a negative impact on learning. In the 1950s, a series of studies suggested academic performance was improved when children consumed breakfast, but, due to small sample sizes and poor experimental designs, no definitive benefits could be documented. In the 1980s, carefully controlled experimental studies in a controlled setting measured problem-solving performance of well-nourished 9- to 11-year-old children after they ate breakfast and after they skipped breakfast (Wurtman 1998). When the children ate breakfast they made fewer errors on tasks of picture identification, response to stimulus on a computer display, and arithmetic tests than when they had skipped breakfast. Good nutrition was also correlated with normal stress levels, that is, undernutirtion was found to cause additional tension for adolescents. (Wurtman 1998) The acute effects of skipping breakfast involve the short term physiologic changes associated with a diminished supply of nutrients to the brain. Under normal short-term fasting conditions, homeostatic mechanisms attempt to maintain blood glucose within physiologic ranges to ensure adequate brain function. A prolonged fast requires more adaptation on the part of the body to maintain blood glucose levels. It may be that a decline (even within normal physiologic range) results in metabolic changes that influence cognition. Over the past years there has been increasing evidence that a moderate elevation of blood glucose regulates a variety of brain functions, including memory and learning. Brain scans show that cognitive functions increase the rate at which glucose is metabolized, and there is some evidence that moderate increases in blood glucose levels improve cognitive functioning in children (Cattell 1996). One proposed mechanism by which raised blood glucose levels may influence cognition is through the synthesis of acetylcholine, a neurotransmitter that has a well-established role in memory functions. The recent studies led participants in a 1995 International Symposium on Breakfast and Performance and Health to conclude that children who skip breakfast are less efficient in problem solving, have reduced recall of newly acquired information, have decreased verbal fluency and creativity, and are more prone to become affected by stress (Muenzinger 1999). The conferees encouraged development of policies to promote recognition of the importance of breakfast and intervention to ensure that breakfast is available to children. Eating breakfast also has a long-term impact on an individual's nutrient intake. When breakfast is skipped, the nutrients usually consumed at the breakfast meal are not recovered from intake during the remainder of the day (Muenzinger 1999). Nonetheless, examination of data from national surveys indicates a decline in breakfast consumption across all age groups. It is estimated that on any given day as many as half of school-age children skip breakfast, but a school breakfast program is associated with decreased absenteeism and tardiness (Muenzinger 1999). Eating habits have an emotional basis. Individuals eat not only because they are hungry but also to fulfill myriad social and psychological needs. Eating when "lonely" or "bored" or "treating oneself to special food as a reward" are simple examples of the emotional use of food. (Cattell 1996) More complex manifestations include denial of hunger or overeating associated with stress or anxiety, all of which can interfere with nutritional well-being. Adolescents become prone to these behaviors as they struggle to establish emotional independence. It is normal for adolescents to be self conscious about or dissatisfied with their changing bodies. A society that emphasizes slimness and the bombardment of advertising that promises thinner thighs and slimmer waists or bigger muscles and a wonderful body create a standard to which teenagers compare themselves, no matter how unrealistic that standard may be. An acute sense of how their bodies differ from the "ideal" may wreak havoc on adolescents' self-esteem. Girls are particularly prone to obsessing about the shape of their bodies, but boys are not immune. Approximately two-thirds of adolescent girls report they are dissatisfied with their weight, and slightly more than half are dissatisfied with the shape of their bodies (Cattell 1996). These percentages increase as body weight increases. African-American girls are less likely to consider themselves overweight than whites or Hispanics (Cattell 1996). Specific concerns of girls are about perceived excess size of their thighs, hips, waist, and buttocks. Boys are more likely to be satisfied with their body weight, but approximately one-third of males expressed dissatisfaction with their body shape, desiring to appear strong and muscular, particularly in the upper body. Adolescents who attempt to lose weight or who struggle to maintain weight are not necessarily overweight by usual standards but perceive themselves as overweight. Such teens tend to have poorer body images and self-esteem than those who are satisfied with their body weight and shape (Muenzinger 1999). The increased nutrition needs of adolescents translate into a demand for a greater quantity of food. Because adolescents eat at home less often, those with limited financial resources may find they are restricted in the amount of food they can afford or the food choices they can make when eating out. For example, a teenager may be able to afford to buy lunch in the school cafeteria but not to join friends at fast food establishments or restaurants. Parents of such adolescents should understand that such situation may cause additional stress for their children.