Adolescence is a golden period for physical and intellectual development. Nutrition is the material basis for ensuring normal growth, development, and maturity. From the ages of twelve to eighteen is a period of rapid growth and development in a person's life, with active endocrine functions, vigorous metabolism, and a lively and active nature. Both large and small muscle groups and various tissues and organs continue to grow, and body shape changes dramatically. According to some data, between the ages of 12 and 18, weight increases by an average of 20 to 30 kilograms, and height increases by an average of 28 to 30 centimeters, with some individuals experiencing even greater growth. To adapt to and meet these growth needs and ensure health, the key factor is whether the supply of various nutrients is sufficient and whether the combination is reasonable, to guarantee their healthy development and growth.
The nutritional needs of adolescents are a complex issue. The biggest difference from adults is that their energy and nutrient supply must not only meet basic physiological needs but also the needs for growth and development, including both physical and intellectual development. Their physiological conditions are constantly changing, their activity levels are high, and there are significant individual differences. Girls develop 1 to 2 years earlier than boys, and their growth patterns are also different. If their special circumstances and needs are not taken into account in their diet, it can directly affect or hinder their normal growth and development, and may even lead to nutritional deficiency diseases, damaging their physique and appearance. Such damage cannot be repaired overnight and may have lifelong effects. For example, long-term deficiencies of protein, calories, and calcium in the diet can lead to incomplete limb development, a thin and small stature, and dry, yellow, and sparse hair. A lack of vitamin A can cause rough skin and follicular keratosis. Other vitamins, such as riboflavin (B2), niacin (PP), C, and E, have protective effects on the skin, and insufficient intake can also cause various skin symptoms. The body's requirement for minerals like potassium, sodium, calcium, magnesium, phosphorus, fluorine, chlorine, iodine, zinc, copper, iron, manganese, selenium, cobalt, and molybdenum is small, measured in milligrams or micrograms, but they are indispensable, and excessive intake can lead to poisoning. For instance, iron deficiency can cause anemia and a pale complexion. Zinc deficiency can hinder adolescent development, leading to short stature and delayed sexual development. Insufficient fluoride intake can result in weak teeth prone to cavities, while excessive intake can cause teeth to lose their luster and develop "mottled enamel," and in severe cases, it can lead to hardening and deformation of bones. During review and exam periods, it is important to supplement the brain with nutrients that are consumed in greater amounts, such as carbohydrates, vitamin C, B vitamins, and iron, to allow the brain to function better.
The main causes of nutritional imbalance are insufficient food supply, poor eating habits, the abuse of supplements, and lack of physical exercise. In real life, many families now have only one child, and the only "treasure" becomes the "god" of the family, which is the negative consequence of excessive doting by elders. In terms of meals, they give the child whatever they ask for, believing it is valuable or rare. Excessive consumption of refined foods is one of the important reasons. Some children also have habits of avoiding certain foods or being picky eaters. They avoid eggs, fish, meat, tomatoes, carrots, etc., leading to nutritional deficiencies due to a reduction in important sources of certain nutrients. Teenagers who like to eat snacks like pastries and candy will affect their normal food intake. Others, especially girls who are beauty-conscious, are afraid of gaining weight and dare not eat this or that. Over time, they become thin, pale, and weak. Some people also become overweight and short of breath or have palpitations due to uncontrolled eating. Other factors, such as irregular eating schedules, improper cooking methods, the abuse of supplements, and lack of physical exercise, can also affect the body's intake of nutrients.
So, what are the daily nutritional needs for adolescents who are in a period of growth and development? This is determined by the standards for the daily dietary nutrient supply for different ages, genders, physiological conditions, and levels of physical activity. Here is a brief introduction to the energy and nutrient needs during adolescence:
1. Energy The energy needs of adolescents are directly proportional to their growth rate. The energy required for growth and development accounts for about 25% to 30% of the total supply. Generally, the energy needs during adolescence exceed those of adults engaged in manual labor. The recommended energy supply is 9.6 to 11.7 megajoules per day (2300 to 2800 kilocalories per day).
2. Protein During adolescence, weight increases by about 30 kilograms, of which 16% is protein. Protein is the material basis for weight gain. The purpose of protein intake for adolescents is to synthesize their own proteins to meet the needs of rapid growth and development. Therefore, protein should account for 13% to 15% of the total energy supply, which is 75 to 90 grams per day.
3. Minerals and Vitamins To meet the needs for rapid bone growth and development, adolescents need to reserve about 200 milligrams of calcium per day, with a recommended supply of 1000 to 1200 milligrams per day. The recommended dietary iron intake for female adolescents is 20 milligrams per day, and 15 milligrams per day for males. The recommended zinc supply is 15 milligrams per day. At the same time, they should often eat grains, legumes, vegetables, and fruits, which are rich in vitamins and dietary fiber. The recommended amount for grains is 400 to 500 grams per day, for legumes 50 grams per day, for vegetables 400 to 500 grams per day, and for fruits 100 to 200 grams per day. From the recommended supply amounts of these nutrients, it is not difficult to see that for some important nutrients like energy, protein, calcium, and iron, the needs of 13 to 17-year-olds are higher than those of adults. For some nutrients like vitamin A, carotene, and vitamin C, the needs are the same as those of adults. This is sufficient to illustrate the nutritional characteristics of adolescents in their growth and development period. Currently, most adolescent students in our country eat meals in group canteens, and their nutritional status is not ideal, with the supply of many nutrients not meeting the standard amounts. This is probably because our relevant personnel have not paid enough attention to the growth characteristics and nutrient needs of this age group. Therefore, it is advocated that school canteens and relevant departments should be equipped with dietitians in the future.
The most important nutrients for adolescents during development:
1. For adolescents in their developmental period
Vitamin B group: Very important for the health of muscles, blood, and the nervous system, so it is crucial for adolescents in their developmental period.
Vitamin C: Due to the current prevalence of dining out and the popularity of fast food, adolescents' intake of fruits and vegetables is very lacking, leading to insufficient vitamin C, so this requires special attention.
Iron: A nutrient that is relatively easy to be deficient in. Deficiency can lead to anemia, slow reactions, irritability, and lack of concentration.
Calcium: Adolescents in their developmental period need large amounts of calcium to help the development of bones and teeth. The absorption of calcium requires the help of vitamin D and magnesium, so attention should be paid to the intake of these nutrients.
2. For adolescents who love sports
Vitamin B group: During exercise, a large amount of heat is consumed, and the vitamin B group is needed to participate in the metabolism of carbohydrates, proteins, and fats to meet energy demands.
Vitamin A, C, and the mineral selenium: Exercise produces more free radicals than usual, so vitamins A, C, and other antioxidants are needed to neutralize them.
Potassium and sodium: A large amount of sweat is lost during exercise, and sodium and potassium are also excreted. Therefore, it is necessary to replenish large amounts of water, sodium, and potassium during exercise.
3. For adolescents with heavy academic workloads
DHA: One of the neurotransmitters in the brain, it helps transmit information in the nervous system, enhances brain power, and improves memory.
Vitamin B group: Can eliminate fatigue and refresh the mind. A deficiency can affect memory.
Vitamin E: An excellent antioxidant that can eliminate free radicals in the body, preventing them from damaging brain cells and thus affecting memory, reaction time, and thinking abilities. Magnesium: Some studies suggest that the inability to concentrate in both adults and children may be related to magnesium deficiency, so adequate magnesium intake can be beneficial for learning.
To facilitate the selection and preparation of foods to meet the nutritional needs of adolescents as much as possible, here are some foods rich in certain nutrients:
Protein: Fish, lean meat, poultry, eggs, milk, legumes, and their products.
Energy: Various animal and vegetable oils, grains, tubers, starches, and sugars.
Vitamin A: Liver, egg yolks, milk, cod liver oil, green leafy vegetables, carrots, tomatoes, and sweet potatoes with red flesh.
Thiamine (B1): Various coarse grains, legumes, meat, fish, eggs, dried beans, and green leafy vegetables.
Riboflavin (B2): Liver, lean meat, eggs, yeast, dried beans, and green leafy vegetables.
Niacin (PP): Lean meat, eggs, fish, milk and dairy products, legumes and their products, and green leafy vegetables.
Vitamin C: Various vegetables and fruits.
Minerals: Various animal foods, fish, and seafood.
Another point that needs to be emphasized is the importance of breakfast for adolescents. Currently, many parents are rushing to work in the morning and neglect their children's breakfast. There is an old Chinese saying: "Eat a good breakfast, a full lunch, and a light dinner." Therefore, the most important thing for breakfast is to provide enough nutritious food. In addition, girls should increase their intake of protein, iron, and vitamin C during their menstrual period. Some adolescents have habits of smoking and drinking, which must be seriously corrected because they are extremely detrimental to growth and development. Excessive drinking can easily lead to thiamine (B1) deficiency, causing loss of appetite and affecting the intake of other nutrients. Smoking can affect or even destroy the body's absorption of vitamin C. Cigarettes also contain nicotine and benzo[a]pyrene; the former has a stimulating and paralyzing effect on the central nervous system, and the latter is a carcinogenic factor for esophageal and lung cancer. Therefore, smoking and drinking are harmful to health.
Finally, a reminder to all adolescents: maintain reasonable nutrition, a balanced diet, and take good care of your bodies. Because you carry the hopes of your parents and the future of the nation, and you have the important responsibility of building the country.