What are the nutritional needs of young athletes? A Parents Guide

The nutritional needs of young athletes at different stages of development

It makes sense that as we grow our nutritional need change. Yet no buzzer goes off to indicate what we may need to change to ensure we are eating for optimal health and sports performance.

All of us, at all ages require a diet that is sufficient in carbohydrate, protein, and fats and abundant in vitamins and minerals. However, nutritional needs change over the various life stages and are further impacted by genetics, health, and activity levels.

It is often assumed that those that follow sporty lifestyles have a lesser presence of nutrient deficiencies, however a recent study observed the same levels of deficiency was present; suspected to be due to the increased activity demands resulting in the body requiring increased nutrient requirements and where intakes were not met nutrients stores were drawn from the body, e.g., calcium drawn from the bone to meet demand [1].

Nutritional needs during adolescence

Biologically, adolescence is the time of life where growth is completed, and individuals become sexually mature.

Timing of the growth spurt and the onset of sexual function which both occur at the start of adolescence vary considerably between individuals.
Between the ages of 10 to 20 years lean body mass will increase from an average 25 to 63kg in boys, and 22 to 42kg in girls.
Body fat also increases from an average of 7 to 9kg in boys and from 5 to 14kg in females.
Total body calcium increases from approximately 300g in both boys and girls to over 1,000g in boys and 750g in girls ^[2]^.

During adolescence social influences become particularly dominate and can play a major role over what food choices are made and what is eaten. Ideals of body image can also be presented and the pressure to change eating habits to conform or rebel. This is often a time where interest is not focused on the nutritional aspects of food but more the following peers, following fads or adopting personal restrictions. It is also a time of rebellion where it is felt the need to adopt different food habits from their parents ^[3]^.

In girls the growth spurt is usually around aged 12 and peak energy intakes have been recorded between 11 to 18 years old.
In boy’s peak height velocity is usually around 14 years and the highest intakes have been recorded between 13 and 18 years old^[4].

Only a small proportion of the extra food is needed to provide the energy for growth, which is estimated to be 6kcal per gram of weight gain corresponds to in about 1% of energy intake at 15 years [5]. Extra energy is in some cases is used for the increased high level of activity ^[6]^.

Among adolescents’ iron is commonly deficient with an increased susceptibility of iron deficiency anaemia due to increased blood volume and muscle mass during growth and development. This raises the need of iron for building up haemoglobin to transport oxygen and the related protein myoglobin in muscle.

In females the need for increased iron is elevated by the beginning of menstruation which will maintain an increased need until menopause [7].

Iron rich foods such as meats, fish, beans dark green vegetables nuts and iron fortified cereals are good sources.
Iron from animal foods has a higher bioavailability than that from non-animal sources and fortified foods.
During adolescence new dietary strategies are often followed such as vegetarianism and therefore an increased risk of iron deficiency is present and careful consideration of food sources should be made.
There is also the need to maintain vitamin C to help the absorption of non-haem iron from non-animal products

During adolescence, an increased need for calcium is required to meet the needs of the growing skeleton.

About 45% of the adult skeletal bone mass is formed during adolescence and therefore it is important that the diet supplies and adequate calcium intake to help build bone density ^[8].
The achievement of peak-bone mass during childhood and adolescence is crucial to reduce the risk of osteoporosis later in life, particularly in females.
Good dietary sources of calcium are dairy products such as milk, yoghurt and cheese and fortified foods.

As well as a good dietary supply of calcium the need for vitamins and minerals like vitamin D and phosphorus are needed to help support the uptake and regulation of calcium to achieve peak-bone mass.

Reports repeatedly present a range of nutrients that are habitually under consumed within adolescence.

The micronutrients that are low in the young populations are also deficient in adult populations suggesting that there is a shortfall of micronutrient intakes in the diet at earlier life stages. Habitually low intakes have been identified below in table 1.

Table 1. At a glance nutritional deficiency commonly seen in the UK adult population.

NUTRIENT	FUNCTION	WHOLE FOOD NATURAL SOURCES (not including fortified foods)
VITAMIN A	Vision, growth and development, immune function, reproduction, haemoglobin, skin, and bone cell formation	Carrots, dairy products, eggs, leafy greens, red peppers, sweet potatoes.
VITAMIN C	Antioxidant activity, enzyme activation, reduces oxidative stress, immune function	Citrus fruits, kiwi fruits, fruit juices, broccoli, sprouts, peppers, tomatoes.
RIBOFLAVIN	Essential in glucose metabolism, free-radical neutralisation (antioxidant properties)	Eggs, beef, poultry, milk, mushrooms, oysters, spinach
B12	Cell metabolism, DNA synthesis, mitochondrial health, aids brain function	Dairy products, eggs, beef, pork, poultry, seafood
D	Bone health, nerve function, muscle contraction, cellular function	Eggs, oily fish, fish oil, mushrooms, pork
B9	DNA replication, vitamin and amino acid metabolism, cell division, reduced risk of neural tube defects in pregnancy	Asparagus, avocados, beans and peas, green leafy greens, oranges, and orange juice
CALCIUM	Bone formation and health, muscle contraction, nerve messenger	Dairy products, green vegetables
MAGNESIUM	Cofactor for many enzyme reactions, metabolism, muscle and nerve function, protein synthesis, glycolysis	Avocado, beans, peas, dairy products, banana, raisins, nuts, pumpkin seeds, potatoes, whole grains
IRON	Formation of haem proteins required of oxygen transport to the red blood cells, flavoproteins, and enzymes activation	Beans, eggs, raisins, prunes, broccoli, spinach, collard greens, meats, nuts, poultry, seafood, seeds, soy
POTASSIUM	Muscle contraction, nutrient transport into cells, toxin clearance from cells	Beans, dairy products, banana, dried apricots, prunes, carrots, seafoods, tomato, potatoes, sweet potatoes, beetroot, spinach
ZINC	Cell mediated immunity, bone formation, soft tissue growth, neurological function,	Beans, peas, beef, dairy products, nuts, poultry, shellfish, whole grains
SELENIUM	Antioxidant, immune support, sperm motility	Eggs, meat, nuts, poultry, seafood wholefoods
IODINE	Growth, metabolism, neurological function, reproduction, thyroid hormone regulation	Dairy products, potatoes, seafood, seaweed, turkey
OMEGA-3 FATTY ACIDS	Neurological development, cell integrity, anti-inflammatory,	salmon, mackerel, sardines, herring and anchovies. Walnuts, pecans and hazelnuts
FIBRE	Digestive motility and regularity, weight management, increased satiety, gut health	Beans and pulses, bread, breakfast cereal, fruit, grains, nuts and seeds, rice and pasta, vegetables

DEFICIENCY OR INSUFFICIENCY. While the nutrients described above have been identified as the nutrients consumed below the lower recommended intakes there is a great concern that there are many of the population who are within what is deemed as a normal intake but is insufficient for their individual needs or life stage [9].

The health dilemma currently facing the UK, Asia and the Americas, is that of over fed, yet under micronutrient nourished children[10].

The increased consumption of processed, high sugar, high fat foods are increasingly abundant, and relatively cheap in comparison to fresh, nutrient rich produce which has led to chronic over consumption [11]. This is a new yet rapidly emerging pandemic, affecting physical and mental health regardless of the individual’s fat mass.

At YSN a whole food first approach is always recommended. The table provides examples of foods to address potential nutritional shortfalls, however the key is variety to ensure all bases are covered.

For those who feel they need a boost, or the daily schedule doesn’t allow a traditional mean the addition of a NUTRI-TEEN is a great way to boost nutritional needs.

Author
Natalie Rouse

First-Class Honours degree in Human Nutrition (BSc Hons), Master of Research in Performance Nutrition and Socio-culture (MRES), Registered and accredited Nutritionist with the Association for Nutrition (ANutri), and Nutritional Consultant and Nutritional Research Scientist (RSci).

References

[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5786912/

[2] https://www.stanfordchildrens.org/en/topic/default?id=the-growing-child-adolescent-13-to-18-years-90-P02175

[3] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4554432/

[4] https://nyaspubs.onlinelibrary.wiley.com/doi/full/10.1111/nyas.13330

[5] Food Portions: Choosing Just Enough for You | NIDDK (nih.gov)

[6] http://www.faqs.org/nutrition/Biographies/Pauling-Linus.htm

[7] https://www.ncbi.nlm.nih.gov/pubmed/10721923

[8] https://www.nichd.nih.gov/health/topics/bonehealth/conditioninfo/children

[9] https://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&cad=rja&uact=8&ved=2ahUKEwiPz-r5-6XxAhUE6OAKHcoYD_YQFjALegQIFBAE&url=https%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fbooks%2FNBK109829%2F&usg=AOvVaw04QA9Uw77pDG0Xkd3Sxy7B

[10] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3257829/

[11] https://www.who.int/news/item/26-09-2019-malnutrition-is-a-world-health-crisis