Nutrition in adolescence

University of KalamoonNutrition Department

Dr. Louay Labban

Puberty Early adolescence

Middle adolescence

Late adolescence

Female 8-11 years 12-14 14-17 18-21

Male 9-11.5 years

12-14 14-17 18-21

Nutrition needs should be determined by the degree of sexual maturation and biological maturity instead of chronological age .

Unhealthy eating behaviors common among adolescence including frequent dieting, meal skipping, high consumption of foods high in fats

Concrete thinking and abstract reasoning abilities do not develop fully until late adolescence or early adulthood

Adjustment to a new body image, adaptation to emerging sexuality

Concrete thinking, early moral concepts

Strong peer effect

Establishment of emotional separation from parents

Expansion of verbal abilities, adjustment to increased school demands

Increased health risk behavior, sexual interests, early vocational plans

Personal identity, further separation from parents

Complex thinking Increased impulse control, emerging

social autonomy, vocational capability

50% of ideal body weight is gained during adolescence

Growth spurt in 3-6 monthsGirls will gain approximately 18 lbs

( 8.3 kg ) yearWeight gain slows during late

adolescence, will gain around 14 lbs ( 6.3 kg )

Lean body mass falls from 80% to 74%

Body fat increases form 16% to 27%During puberty, females experience

44% increase in lean body mass and 120% of body fat mass each year.

Males gain 20 lbs ( 9 kg ) per year during puberty

Fat decreases in males during adolescence to reach 12%

By age 18, more than 90% of skeletal mass has been formed

A variety of factors contribute to the accretion of bone mass including genetics, hormonal changes, smoking and nutrition

Eating patterns and behaviors of adolescents are affected by many factors:

Peer influenceParental modelingFood availabilityFood preference

CostConveniencePersonal and cultural beliefs Mass mediaBody image

Eating habits of adolescents are not static

They fluctuate throughout adolescence in relation to psychological and cognitive development

Adolescents lead busy lives Many involved in extracurricular sport

or academic activities This leave little time to sit and eat meal Snacking or meal skipping are common

Almost all adolescents consume one snack per day ( range 1- 7 )

One study showed that adolescents ate 18.2 meals and 10.9 snacks in a week

Snacks account foe 25% to 33% of daily energy intake

Snacks consumption has risen during the past decade

The occurrence of meal skipping increases as adolescents mature

Breakfast is the most commonly skipped meal

29% of female adolescents tend to eat breakfast

Skipping breakfast can dramatically decreases intakes of energy, protein, fiber, Ca, and folate

25% of adolescents skip lunch

As adolescents mature, they spend less time with the family and more time with peer

Eating away from homeFemales eat 1/3 of meals away from

homeFast food accounts for 33% of food

eaten

Eating at fast food restaurant has a direct bearing on the nutritional status of the adolescents

Fast foods are high in fats Low in fiber and nutrients

Vegetarian diets are consumed in 1% of adolescents

Vegetarian diets are consumed for many reasons

Vegetarian adolescents found to be shorter and leaner than omnivores during childhood and early puberty age

Menarche occurs 6 months later in vegetarian females

Vegetarian adolescents are taller or as tall as the omnivores but generally leaner

When well-planned, vegetarian diets provide health benefit to adolescents such as complex CHO intake , high vitamin intake and protein

With supplements from small amounts of animal foods such as milk and its products,

Vegetarian diets should include adequate fats and essential fatty acids ( DHA, EPA )

Type of vegetarian diet Food excluded

Semi- or partial vegetarian Red meat

Lacto-ovo-vegetarian Meat, poultry, fish, seafood

Laxctovegetarian Meat, poultry, fish, seafood and eggs

Vegan ( total vegetarian ) Meat, poultry, fish, seafood, eggs, dairy products ( may exclude honey )

Macrobiotic Meat, poultry, eggs, dairy, seafood, fish ( fish may be included in some macrobiotic vegetarians)

Food groups Lcato-ovo-vegetarians11 years2200-2800 kcal

Vegans11 years2200-2800

Breads, grain, cereal 9-11 10-12

Legumes 2-3 2-5

Vegetables 4-5 3-5

Fruits 4 4-5

Nuts, seed 1 4-6

Milk, yogurt, cheese 3 0

Eggs ( limit 3/week ) ½ 0`

Fats , oils ( added ) 4-6 4-6

Sugar ( added teaspoons )

6-9 6-9

Food source Alph-lenolenic acid, g

Flaxseed, 2 tb 4.3

Walnuts, 1 oz`` 1.9

Walnut oil, 1 tb 1.5

Canola oil, 1 tb 1.6

Soybean oil, 1 tb 0.9

Soybean, ½ cup cooked 0.5

Tofu, ½ cup 0.4

Most diets do not match the dietary guidelines

1% of teens consume diets that meet the recommendations for all food groups

45% of teens meet recommendations for one group or more

7% of males and 18% of females adolescents do not meet any of the recommendations

Male % Female %

Dairy products 49 22

Fruits 17 19

Vegetables 50 46

Grains 43 21

Increases in lean body mass, skeletal mass and body fat during puberty result in energy and nutrient needs that exceed those of any other point of life

Energy and nutrient requirements correspond with the degree of physical maturation

Influenced by:Activity levelBMR Increased requirements to support

pubertal growth

Influenced by many factorsRDA for protein intake is:9-13 years old 0.95/g/kg/day14-18 years old 0.85/g/kg/dayWhen protein is inadequate, growth,

sexual maturity delay and reduced accumulation of lean body mass

Primary source of energyFrom fruits, vegetables, whole grains

and legumes55-60% of total energy< 10% form sweeteners but

adolescents consume about 16% of total energy for soft drinks

Ounces per day Adolescents %

> 26 oz per day 22

13-25 oz per day 28

0.1 12 oz per day 32

0 oz per day 18

Life-stage group

Calorie kcal

Protein grams

Age, years Kcal/day Kcal/ cm Grams/day Grams/cm

Females 11-14 15-18 19-24

220022002200

14.013.513.4

464446

0.290.270.28

Males 11-14 15-18 19-24

250030002900

15.917.016.4

455958

0.290.340.33

AAP Recommends 0.5 g/kg/day of fiber Or 15.5-34.5 g/ day for 10-18 years old

males 16-28.5 g/day for 10-18 years old

females National data shows consumption is: 11.5-15.4 g/day for males 10-14 g/day for females Because low intake of fruits and

vegetables

Essential for growth and development National cholesterol education

program NCEP recommends no more than 30% of total energy should come from fat

< 10% from saturated fat DRI recommendations: 4-18 years old should consume 25-

35% of total fats

Teens consume around 33% of total energy from fats

Over 12% from saturated fats

adequate intake is important for growth and development

Important for bone massFemales have the greatest capability

of absorbing calcium at time of menarche then decreasing after

By age 24 for females and 26 for males calcium accretion is almost nonexistent

DRIs for 9-18 years is 1300 mg/day Adolescents females consume 536-

815 mg/day Adolescents males consume 681-1146

mg/day Milk is the best source followed by

cheese, ice cream and frozen yogurt Consumption of soft drinks may

displace the consumption of more nutrient dense beverages such as milk and fortified juices

Growth at this stage increases blood volume

Menarche increases the need for iron

Group Ca mg/d

P mg/d

Mg mg/d

Vit Dmcg/d

Iron mg/d

B1mg/d

B2 mg/d

B3 mg/d

Males 9-13 14-18Females 9-13 14-18

13001300

13001300

12501250

12501250

240410

240360

55

55

811

815

0.91.2

0.91.0

0.91.3

0.91.0

1216

1214

Group B6 mg/d

B9 mg/d

B12mg/d

B5 mg/d

B7 mcg/d

Vit A mcg/d

Vit C mg/d

Vit E mg/d

Se mcg/d

Males 9-1314-18Females 9-1314-18

1.01.3

1.01.2

300400

300400

1.82.4

1.82.4

45

45

2025

2025

600900

600700

4575

4565

1115

1115

4045

4055