Chapter 14: Adolescent Nutrition

Adolescence

11 or 12 to 21

Nutrition requirements are more associated with....

stage of sextual maturity/ biological age then chronological age

Nutritional needs are based on...

physiological development

Who hits puberty first?

Girls

Girls typically develop physically before

cognitively

Boys develop physically and cognitively...

at approximately the same time

Psychosocial development

formation of our identity

Reasons for changing DRI's

rapid period of physical growth and development dramatically increase energy, protein, and micronutrients needs this

Influences on DRI requirements

Sexual maturation

Increase in height, weight, skeletal mass

Changes in lean mass & fat mass

In adolescence, growth spurts are usually....

height followed by weight gain

Girls peak in growth around...

SMR Stage 2-3 (6-12 mo. before menarche)

Menarche

mean of age= 12.5 years

As much as 15-25% of final adult height is gained during...

puberty

As much as 50% of ideal body weight..

is gained during adolescence

Boys peak in growth velocity around...

SMR 4 or 14.4 yo

Male puberty occurs between the ages of...

10.5-14.5 yo

Male age range for height spurt is..

10.5 to 17.5 yo

Snacks make up to what % of added sugar intake

36%

What estimated % of our food supply is "ultra processed"

73%

What % of American calories from from "ultra processed" foods

57%

What percent of our added sugar intake is from "ultra processed" foods

90%

Typical eating habits of adolescents

eating on the go

increase in fast food

more snacks

skipping meals

decrease in breakfast eating

Physiological effects we tend to see in vegetarians

later puberty

leaner later as adults

decreased risk of CVD and cancer

Vegetarian teens are more then 2x likely to...

report frequent or chronic dieting

Vegetarian teens are 4x as likely to...

report laxative use

Do adolescents have room for empty calories in their diets?

Some do, it depends on their PA

Why do some adolescent athletes engage in weight cycling?

to enhance performance

to make a weight category for weight class athletes

to enhance the aesthetics of performance

The 4 main methods used by athletes to achieve rapid weight loss

1. Active method

2. Diet- induced

3. Taking Diuretics

4. Very-low-calorie diets

Active method

increasing metabolic rate via exercise to increase rate of heat production

Diet method

Consuming foods to induce fluid loss, high protein, low carb

Taking diuretics

OTCD r other meds to promote urine production

Very low calorie diets

typically 500-800 kcal/day or less

Risks associated with very low calorie diets & rapid weight loss

Cardiovascular problems

Endocrine problems

Changes in thyroid function

Immune system is impaired

Cardiovascular problems

myofibrillar damage, hypotension, sudden cardiac arrest

Endocrine problems

decreased insulin-like growth factor

Changes in Thyroid function

T4 (thyroxine) decreases; response to TSH is lower, GnRH is reduced decreasing LH and FSH

Immune system is impaired

decreases in cell-mediated immunity, phagocytic function, immunoglobulin A and cytokines production

Among athletes what percent may be affected by disordered eating?

62%

Dangers of weight cycling during adolescence

Increase in cardiovascular risk:

1. hypertension

2 visceral fat accumulation

3. insulin resistance

4. dyslipidemia

5. fluctuations in BP, heart rate

Why would it be best to base DRI on height rather then weight?

Indicates stage of growth better

Female energy DRI for ages 9-13

1,900 or 2,100 kcal/day

Female energy DRI for ages 14-18

2,300 kcal/day

Female energy DRI for ages 19-30

2,300 kcal/day

Male energy DRI for ages 9-13

2,200 kcal/day

Male energy DRI for ages 14-18

3,100 kcal/day

Male energy DRI for ages 19-30

3,000 kcal/day

Females energy needs increase by...

~425 kcal/day between 9-13 y and 14-18 y then remains constant

Male energy needs increase by...

~950 kcal/day between 9-13 and 14-18 y then decreases slightly

What factors are two primary influences on protein requirements in most adolescents.

Growth rate

Lean body mass

Male & Female protein DRI for ages 9-13

0.95 g/kg/day

Male & Female protein DRI for ages 14-18

0.85 g/kg/day

Male & Female protein DRI for ages 19-30

0.80 g/kg/day

Female protein DRI in grams for ages 9-13

34 g/day

Female protein DRI in grams for ages 14-18 & 19-30

46 g/day

Male protein DRI in grams for ages 9-13

34 g/day

Male protein DRI in grams for ages 14-18

52 g/day

Male protein DRI in grams for ages 19-30

56 g/day

Peak height growth for females is ages

9.5 to 14.5 years old

Does the protein DRI for females at peak height growth reflect the need for protein?

No, b/c ages 9-13 has the lowest DRI for protein (g/day)

Peak height growth for males is ages

10.5-17.5 years old

Does the protein DRI for males at peak height growth reflect the need for protein?

Yes, their is a huge increase in protein DRI from 9-13 to 14-18 yr old

Fat DRIs for Males and Females

25-35% of total calories

needed for energy

DRI for all B-vitamins involved in energy metabolism..

increase during adolescence

Calcium DRI for males and females ages 9-13 & 14-18

1,300 mg/day

Calcium DRI for males and females ages 19-30

1,000 mg/day

Why does calcium decrease at 19-30 yr

bone mass is pretty much complete

At age 18 y what % of bone mass has accrued

90% of bone mass

At what age do we reach peak bone mineral density?

age 30

For males and females the vitamin D DRI is

15 mcg/day or 600 IU/day

Estimated avg. intake of vitamin D is

4.9 mcg/day or abt 1/3 of recommended amount

What is the most common nutrient deficiency in adolescence

Iron

Iron DRI for females and males ages 9-13

8 mg/day

Iron DRI for females ages 14-18

15 mg/day

Iron DRI for females ages 19-30

18 mg/day

Iron DRI for males ages 14-18

11 mg/day

Iron DRI for males ages 19-30

8 mg/day

What is zinc needed for?

Glucose metabolism, activation of many enzymes needed for protein synthesis, growth & metabolism, appetite regulation, and sperm health

Zinc DRI for females ages 9-13 & 19-30

8 mg/day

Zinc DRI for females ages 14-18

9 mg/day

Zinc DRI for males ages 9-13

8 mg/day

Zinc DRI for males ages 14-18 & 19-30

11 mg/day

Use of folate

coenzyme in DNA synthesis, needed for cell division/ replication, needed for RBC formation

Folate DRI for females and males ages 9-13

300 mcg/day

Folate DRI for females and males ages 14-18 & 19-30

400 mcg/day

Vitamin C DRI for females & males ages 9-13

45 mg/day

Vitamin C DRI for female ages 14-18

65 mg/day

Vitamin C DRI for female ages 19-30

75 mg/day

Vitamin C DRI for males ages 14-18

75 mg/day

Vitamin C DRI for males ages 19-30

90 mg/day

Vitamin E DRI for females & males ages 9-13

11 mg/day

Vitamin E DRI for females & males ages 14-18 & 19-30

15 mg/day