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Nutritional Intakes and Status as Reported in Surveys 175
girls but is likely to be unheeded. A folate-rich diet higher, at 14.8 mg/day to allow for menstrual losses.
should therefore be recommended to all teenage
girls, which would involve an increased intake of:
●● yeast extract
●● pulses – peas and beans
●● oranges and orange juice
●● green leafy vegetables (brussels sprouts, spinach
and broccoli).
Minerals
The RNIs for calcium, phosphorus and iron in both
genders, and magnesium in girls, are higher for
adolescents than for adults. This reflects the
increased needs for growth and development.
Calcium and phosphorus
Calcium and phosphorus are important for the
rapid accretion of bone tissue. Sixty per cent of
adult bone mass is gained during the pubertal
growth spurt. Even after the growth spurt,
calcification of bones continues as peak bone
mass is reached at most bone sites from 16 to 30
years. Although 70–80 per cent of peak bone
mass is determined by genetic factors, the
remaining 20–30 per cent can be influenced by
diet and exercise. In the UK, white and Asian
teenagers are more susceptible to poor bone
mass than other races. Adequate calcium intakes
at this age may protect against osteoporosis in
later life.
Low bone density and bone fractures in teenage
girls are associated with a high intake of carbonated
drinks (Wyshak 2000). The reason why is not clear
but it may be due to the high phosphate content of
carbonated drinks disturbing bone physiology
along with the low-calcium diets adolescents tend
towards by not having three daily servings of milk,
cheese and yogurt.
Iron
Iron is a key nutrient during growth since it is a
component of muscle and blood. The RNI of
11.3 mg/day set for boys 11–18 years old is higher
than that for either younger or adult males. The
iron requirement for girls 11–18 years old is even
Achieving adequate iron stores becomes important
for girls as menstrual periods become more regular
and heavier as they mature.
Healthy Eating
The guidelines on healthy eating for adolescents
are based on a number of daily servings from each
of the five food groups in the ‘eatwell plate’ (see
Chapter 1.2). Three large servings of milk, cheese
or yogurt will ensure that calcium and phosphorus
requirements are met to ensure bone deposition.
Consuming two servings per day, or three for
vegetarians, from the meat, fish, eggs, nuts and
pulses group each day will ensure the extra iron
requirement is met.
Portion sizes vary depending on size, gender
and activity levels. Table 6.2.1 provides a rough
guide but portions may increase during the
pubertal growth spurt and for physical training.
Nutritious snacks will provide extra energy
and boost nutrient intake and should be
encouraged – particularly fortified foods such as
breakfast cereals and bread (see Chapter 1.2).
However, adolescents tend to snack outside the
home and advice on healthier convenience and
take-away foods with less fat, sugar and salt is
appropriate. Some suggestions are provided in
Table 6.2.2.
Nutritional Intakes and Status as
Reported in Surveys
Despite their high requirements for nutrients, the
food choices of adolescents in the UK tend to be
poor compared to the food eaten by younger
children.
Evidence for this comes from the National Diet
and Nutrition Surveys in the UK (Gregory et al.
2000, Department of Health 2011) which show that
many adolescents have very poor nutrient intakes
of key vitamins and minerals. The current rolling
programme found in the first two years that a large
percentage of 11–18 year olds were not eating