Adolescence is a crucial period of rapid change. A focus on sensible nutrition during these years can help to lay the foundation for a long and healthy life. This article highlights the role of key nutrients and where best to find them.
Adolescence is the gateway to adulthood, not only heralding critical physical changes but also setting the scene for emotional, intellectual and social maturity. During this time – which typically spans around ages 12 to 19 years – the accelerated growth rate echoes that of early childhood and culminates in teenagers reaching most of their adult height and weight. Sexual development is a key aspect of adolescence and is reflected in changes in body composition. For girls, this generally means an increase from around 19% to 22% body fat as their pre-pubescent bodies take on rounder, more feminine curves. Boys, although their body fat usually remains unchanged at about 15%, can gain more than twice the muscle mass of girls.
Given all this growth and development, it is hardly surprising that optimal nutrition is absolutely vital during adolescence … and yet, ironically, this can also be a time when teens are particularly vulnerable to deficiencies. Growing independence from parents is often accompanied by the desire to make personal food choices. As part of this muscle-flexing, food can become the target of peer pressure, media messages and body image issues, and even a weapon of defiance.
Teaching teens the value of delicious, whole- some food and its importance to glowing health and physical stamina is an excellent starting point for parents – particularly if parents also lead by example and can be seen to ‘walk the talk’. Strong bodies, clear minds and boundless energy are our birthright – whatever our age.
CARBOHYDRATES, PROTEIN AND FAT
These are collectively called ‘macro-nutrients’, as the body needs them in large (macro) quantities.
- Carbs. Growth requires energy, which explains why teenagers often have voracious appetites. Although carbohydrates are the body’s main fuel, some forms provide longer-lasting energy than others. So-called complex carbs found in starchy foods are bound together with fibre that helps to slow down their conversion to blood sugar. This encourages more balanced energy and mood levels, and also helps to combat sugary food cravings. Wholewheat bread and pasta, brown rice, rolled oats, peas, beans and lentils are all rich sources of energy-sustaining complex carbs.
- Protein is essential for building, repairing and maintaining the body from the inside out, so this is another vital nutrient for the growing and developing adolescent body. Fish, poultry, lean red meat, eggs, nuts and seeds are excellent sources of protein. For a meat-free variation, combining grains (e.g. wheat, rye, rice) with legumes (beans, peas, lentils) provides a protein-content equal to meat.
- Fat has a host of uses in the body, ranging from energy to brain activity, so it’s easy to see how it earns its place as an essential teen nutrient. Saturated fats are generally best eaten in small quantities, as they are very energy-dense. Untrimmed meat, butter and cheese are all rich animal sources.
Polyunsaturated fats include the essential omegas 3 and 6, which have an impressive array of activities spanning hormones, skin and brain. Oily fish (remember SMASH: salmon, mackerel, anchovies, sardines, herring), nuts, seeds, avocados and olives are all delicious ways to top up polyunsaturated fats. A deficiency in essential omegas may result in dry skin, hair and eyes, sore joints, compromised immunity and depression.1
VITAMINS AND MINERALS
These fall under the heading ‘micro-nutrients’, as they are only required in very small (micro) quantities.
- Vitamin A is a crucial nutrient in puberty, as it helps to stimulate the growth and development of cells, including those related to reproduction. Its precursor is beta-carotene, which the body converts to vitamin A. The richest food sources of fat-soluble vitamin A are liver, kidney, butter and whole milk.
Beta-carotene is found in carrots, sweet potatoes, butternut, spinach, apricots and green peppers. Deficiency signs include compromised immunity, goose-bump skin on the back of the upper arms, and night blindness.
- The B vitamins are a family of related nutrients which include B1 (thiamine), B2 (riboflavin), B3 (niacin), B5 (pantothenic acid), B6 (pryridoxine), B12 (cobalamin), biotin and folic acid. Collectively, these vitamins play a vital role in the conversion of food to energy and are therefore fundamental to adolescent growth and development. Eating a wide variety of foods will help give access to B vitamins: go for whole grains, rice, nuts, dairy, eggs, meats, fish, fruits and leafy green vegetables. Signs of deficiency are likely to include fatigue, depression, dermatitis, cracked lips and tongue, and pins and needles.
- Calcium is necessary for the development of bones and teeth. This mineral is especially significant for teens, as half of the body’s skeletal growth takes place during these years. Although dairy is often touted as the best source of calcium, it may also increase intake of saturated fat. Plant-based sources can help to overcome this, and have the added advantage of digestion-supporting fibre: they include leafy greens, parsley, watercress, nuts, seeds and olives. A calcium deficiency may manifest as muscle spasms and leg cramps.
- Iron is essential to life – without it red blood cells would not be able to transport energy-sparking oxygen around the body. Adolescent girls and boys both need iron, although for different reasons. Girls need it to replace blood lost during the menstrual cycle, while for boys it is vital for the increase in blood volume that accompanies their more dramatic growth spurts. Red meat and liver are excellent sources of iron which are relatively easily absorbed by the body. Eggs and plant-based options such as nuts, seeds, prunes, raisins and beans contain a less easily absorbed form of iron. Combining these foods with a source of vitamin C can help improve iron absorption – e.g. orange juice with eggs, fresh fruit with nuts. Leafy vegetables also fall into this category, and already contain vitamin C. Deficiency signs of iron can include impaired immune function and fatigue.
- Zinc is intimately involved in the action of many hormones, including growth and sex hormones, so is essential during puberty. Although the best-known source is probably oysters, seafood in general is relatively high in this key mineral. Other good sources include red meat, while plant foods such as whole grains, nuts, seeds and beans contain a fibre compound (phytic acid) that makes zinc less absorbable. Zinc deficiency may result in white spots on the nails, stretch marks, poor senses of taste and smell, compromised immunity, skin complaints, delayed sexual development and slow wound healing.
Nutrition begins with good-quality, wholesome food – but, sadly, air and soil pollution combined with mass farming and cultivation have eroded the nutrient content of much of the produce available to us today. Supplements can be helpful in bridging these gaps, particularly during adolescence when nutritional demands are at a peak and eating habits may not be supporting them properly.
According to a recent Human Sciences Research Council (HSRC) health study on South African children, conducted in August 2013:2
- 43% of children between the ages of two and five tested vitamin A-deficient.
- The World Health Organisation (WHO) considers a country in which more than 20% of children are vitamin A-deficient to have a ‘severe’ health problem.
- Lack of vitamin A weakens the immune system, putting children at risk of frequent diarrhoeal diseases and respiratory infections.
- 26% of children aged between one and three are below average height for their age, and 9.5% are severely retarded in their growth.
- Vitamin A-deficient children developed mouth ulcers, poor night vision, dry flaky skin, dandruff, and frequently contracted colds and other infections.
- Vitamin A and other vitamins were removed from processed foods because they reduced the products’ shelf life.
- Only 8% of children in South Africa are exclusively breast-fed until the age of six months, which is one of the lowest rates in the world.
These deficiencies can have a long term impact on growth and development. If in doubt, choose a high-quality, comprehensive multivitamin/mineral formulation designed for teens – or one for adults, and follow the suggested dosage for adolescents.
If you suspect a deficiency in specific nutrients, it’s safer to avoid self-supplementing. Instead refer to a health professional who will be able to provide the necessary expertise.
Adolescence is a time of remarkable growth and change, which demands top-quality nutrition. Investing in food choices that address these needs can help to pave the way for a long and healthy life.
- Murray MT. Encyclopedia of Nutritional Supplements. New York: Three Rivers Press, 1996.
- Human Sciences research Council: Nutritional status of children. 6 August 2013.
- Tuck shop truths study reveals poor offerings.