Download - Adolescent Nutrition
ADOLESCENT NUTRITION
Dr.Fatemeh Famouri
Pediatric Gastroenterologist
ADOLESCENCE
It is the time between the onset of puberty and adulthood (11- 17 years old)
Boys grow about 8 inches, gain about 45 pounds and increase their lean body mass. Girls grow about 6 inches, gain about 35 pounds and increase their body fat.
Growth through adolescence is hormone driven. Growth spurts for girls
begin between ages 10.5 and 11 years with a peak in the rate of growth at around age 12.
Considerable gain in muscle and bone mass
DEFINITION
• Early adolescence: 10 -15 years;• Mid adolescence: 15-17;• Late adolescence : 17-21, but variable.
differences between genders becomes apparent females: higher fat
percentage males: more lean body
mass
Adolescence is an uncomfortable time for the teen who is concerned with body image or body changes or athletic activities.
Low nutrient snacks are a large part of the diet and adequate amounts of fruits and vegetables are missing.
Factors that determine food selection and consumption include the desire to behealthy, fitness goals, amount of discretionary income, social practices and peers.
• improved nutrition in adolescence,particularly in girls, is the reduced risk of osteoporosis in older age.
• stunting becomes a permanent consequence of past malnutrition rather than being a sign of present malnutrition.
• If there is indeed catch-up growth in height, adolescence can provide a final chance for intervention to promote additional growth,with potential benefit in terms of physical work capacity and for girls, of diminished obstetric risk .
Linear growth may be limited by multiple simultaneous nutrient deficiencies in many populations,
which could explain that interventions with specific individual nutrients (eg, vitamin A, iron, zinc)
increased pre-pregnancy weight and body stores of nutrients, thus contributing to improved future pregnancy and lactation outcome,
improved iron status with reduced risk of anaemia in pregnancy, low birth weight, maternal morbidity and mortality, and with enhanced work productivity and perhaps linear growth;
improved folate status, with reduced risk of neural tube defects in the newborn and megaloblastic anaemia in pregnancy.
Small girls are likely to become small women who are more likely to have small babies, particularly if at a young age
The overall nutritional status is better assessed with anthropometry, in adolescence as well as at other stages of the life cycle. Anthropometry is the single most inexpensive, non-invasive and universally applicable method of assessing body composition, size and proportions
Iodine deficiency disorders Iodine deficiency disorders were widely
prevalent in most populations Neuromotor and cognitive impairments of
variable degrees Iodine deficiency is recognized as the most
common cause of preventable mental retardation in the world.
ZINC
Evidence from supplementation trials suggests that marginal zinc nutriture may also limit skeletal growth
zinc supplementation increased accretion of fat-free mass and enhanced linear growth in those that were stunted at baseline
Figure 18.4
CALCIUM ½ of peak bone mass
accumulates in adolescence
AI for calcium = 1,300 mg for ages 9–18 years Inadequate calcium intake
can lead to low peak bone mass and is a risk factor for osteoporosis
TEENAGERS AND CALCIUM
Teenagers have high calcium requirements.
Around 50% of the adult skeleton is formed during the teenage years (RNI - boys 1000 mg/day, girls 800 mg/day).
Low calcium intakes (< LRNI) found in 24% of 11-14 year-old girls and 19% of 15-18 year-old girls.
A lack of calcium may have consequences for future bone health e.g. increased risk of osteoporosis.
IRON
Additional iron supports muscle growth and increased blood volume Adolescent females need iron to support
menstruation RDA for iron
Females aged 14–18 years = 15 milligrams Males aged 14–18 years = 11 milligrams
Iron deficiency is common in adolescence, especially among individuals who limit intake of enriched grains, lean meats, and legumes
IRON ABSORPTION Good sources: meat (especially lean red meat),
liver and offal, green leafy vegetables, pulses (beans, lentils), dried fruit, nuts and seeds, bread and fortified breakfast cereals.
Iron from meat sources (heme iron) is readily absorbed by the body.
Vitamin C helps the body to absorb iron from other sources (non-heme iron).
A HEALTHY DIET IS IMPORTANT FOR TEENAGERS
Eating a healthy, balanced diet can:
• promote wellbeing by improving mood, energy and self-esteem to help reduce anxiety and stress;
• best concentration and performance;
• reduce the risk of ill-health now and in the future, e.g. obesity, heart disease, cancer, and type 2 diabetes;
• increase productivity/attainment and reduce days off sick.
NUTRIENT NEEDS OF ADOLESCENTS Growth not age should be ultimate indicator of nutrient needs. Energy needs are greater during adolescence than at any other time of life
with exception of pregnancy & lactation. Energy & Proteins RDAsMales Age (yrs) Kcal/kg Kcal/day Proteins g/kg Proteins
gm/day 11-14 55 2500 1.0 4515-18 45 3000 0.9 59FemalesAge (yrs) Kcal/kg Kcal/day Proteins g/kg Proteins
gm/day 11-14 47 2200 1.0 4615-18 40 2200 0.9 44 Vitamins & Minerals Higher vitamins and minerals needs. Three nutrients of importance i.e. vitamin A, iron and calcium. AI for calcium 1300 mg/day, for iron is 11 mg/day (boys) and 15 mg/day
(girls). Improving fruit & vegetable intake will help in obtaining adequate vitamin A.
DIETARY RECOMMENDATIONS
Teenagers should consume a variety of foods from each of the four main food groups:
Fruit and vegetables (33%)
Bread, rice, potatoes, pasta and other starchy
foods (33%)
Milk and dairy foods (15%)
Meat, fish, eggs, beans and other non-dairy
sources of protein (12%)
FOOD GUIDE PYRAMID
serving sizes can help you control the amount of calories, fat, saturated fat, cholesterol, sugar or sodium in your diet.
Grains, Bread, Cereal and Pasta form the Base Fruits and Vegetables Lean Meat and Fish, Beans, Eggs Dairy Products Fats and Sweets
MACRONUTRIENTS
MacronutrientRecommended intake (% food energy)
Boys average intake
(% food energy)
Girls average intake
(% food energy)
Fat35%35.4%35.9%
of which saturates
11%14.2%14.3%
Carbohydrate50%51.6%51.1%
of which added sugars (NMES)
11%16.7%16.4%
-average intakes (Scottish NDNS and Survey of Sugar Intake
data)
WHAT ABOUT DIETARY FIBER?
average dietary fibre intakes to be low in teenagers:
- Boys (11-14 years) 11.6 g/day (15-18 years) 13.3 g/day - Girls (11–14 years) 10.2 g/day (15-18 years) 10.6 g/day
Reference values:- 15 g/day (11-14 years)- 18 g/day (15 years or above)
WHAT ABOUT SALT?
NDNS survey results - average salt intakes above recommendations in teenagers:
- Boys (11-14 years) 6.75 g/day (15-18 years) 8.25 g/day - Girls (11-18 years) 5.75 g/day (excluding salt added in cooking or at the
table Recommended maximum daily salt intake: - 11 years and over: up to 6 g/day.
TEENAGERS AND ENERGY BALANCE Levels of overweight and obesity are increasing: 35%
of teenagers (12-15 years) are classified as overweight or obese (Scottish Health Survey 2009).
Teenagers, especially girls, often try to control their weight by adopting very low energy diets or smoking.
Restricted diets may lead to nutrient deficiencies and other health consequences.
Teenagers of unhealthy weight may need guidance on lifestyle changes to help them achieve a healthy
weight.
TEENAGERS – PHYSICAL ACTIVITY Physical activity through life is important for
maintaining energy balance and overall health. At least 60 mins of moderate-intensity physical
activity each day is recommended. Include activities that improve bone health, muscle
strength and flexibility at least twice per week.
68% of boys and 41% of girls (13-15 year-olds) achieve the recommended 60 mins per day
DIET AND COGNITIVE ABILITY
• Food eaten at school can make up a substantial proportion of the diet and have a significant effect on functions such as learning, memory, information processing and mood.
• Cognition represents a complex multidimensional set of abilities and cognitive performance is affected by many influencing factors.
• Nutritional effects are difficult to measure.
Stevenson J (2006) Dietary influences on cognitive development and behaviour in children Proct Nutr Soc
65(4):361-5.
Bellisle F (2004) Effects of diet on behaviour and cognition in children Br J Nutr 92 Suppl 2: S227-32.
GLYCEMIA
The brain appears to be sensitive to short-term fluctuations of glucose supply and therefore it
might be beneficial to maintain glycemia at adequate levels to optimise cognition.
EATING BREAKFAST
Starting each day with breakfast will supply energy to the brain & body.
Eating breakfast leads to improved energy and concentration levels throughout the morning.
Breakfast consumption may improve cognitive function related to performance in school.
Improvement of memory
Other benefits of breakfast include better nutrient intakes and weight control.
•Even mild dehydration (1-2%) can lead to headaches, irritability and loss of concentration. This level is not enough to cause feelings of thirst.
•The recommendation is to drink 6-8 glasses/day (1.2 litres) to prevent dehydration. People need to drink more when the weather is hot or when they have been active.
•All drinks count in terms of fluid intake but those without sugar are best between meals.
FLUIDS AND HYDRATION
DIET AND IQ Brain health depends on optimal intakes of
nutrients from the diet.
Much speculation about the importance of long chain omega-3 fatty acids to behavioural and cognitive development, including IQ.
Supplementation studies show the best outcome observed in children with learning disabilities.
Current recommendation is one portion of oily fish (140g) per week.
DIET AND MOOD/BEHAVIOUR There are a number of foods that have a
pharmacological effect in the body which affects mood:
* caffeine;* vaso-active amines, such as histamine;* tryptophan and serotonin.
There is evidence to suggest that poor vitamin and mineral status may be associated with poor educational attainment and antisocial behaviour.
FOOD ADDITIVES AND HYPERACTIVITY
The Southampton study suggested that consumption of mixes of certain artificial food colours and the preservative sodium benzoate could be linked to increased hyperactivity in some children. The colours are:
sunset yellow FCF (E110) quinoline yellow (E104) carmoisine (E122) allura red (E129) tartrazine (E102) ponceau 4R (E124)
An EU-wide mandatory warning must be put on any food and drink (except drinks with more than 1.2% alcohol) that contains any of the six colours.
Bateman B et al. 2007
EATING HABITS irregular eating habits snacks generally provide ¼ of daily energy
intake more fast food: less fruits, vegetables, milk food choices are often dictated by peers
WHAT DO BOYS AND GIRLS WANT?
boysys usually want to gain muscle and
get tallerGirls usually want to
control their weight
FOR GIRLS SOME ADDITION OF FAT IS NATURAL
Need at least 17% body fat for normal periods
Diet is a four letter word
Improve eating habits and activity – but don’t starve or over exercise
BOYS MATURE LATER
Growth spurt up to 2 years later than girls
Full muscle mass doesn’t develop until one year after full height achieved
Excess calories and protein won’t speed things up
MAKE EVERY DRINK COUNT
Cut the soft drinks
Drink 3-4 cups of milk Drink at least 4 more
cups of water or juice
(watch the juice – it has calories)
DURING A SPORTS EVENT
Drink at least 2 cups of water before event
Continue to drink 4 ounces every half hour
Cool, not cold, water is best
Replace two cups of fluid for every pound lost
EAT AT LEAST 5 SERVINGS OF FRUITS AND VEGETABLES
Lots of vitamins and minerals with few calories
More fiber so you feel full
Portion size – palm of girl’s hand
EAT MORE WHOLE GRAIN BREADS AND CEREALS
Won’t cause weight gain if don’t eat too much
Depending on body size, will need 6-11 servings
Portion size – the palm of a girl’s hand
GET ENOUGH PROTEIN BUT NOT TOO MUCH
Get protein from lean meat, fish and poultry
Portion size – palm of girl’s hand
Protein also comes from dairy foods, dried beans and peas, peanut butter, nuts, seeds, soy foods
Limit low nutrient foods with lots of fat, sugar and sodium
Make fast food a special occasion choose grilled or broiled
meat, fish or poultry choose side salads,
baked potatoes choose milk, water or
juice
DISORDERED EATING
Disordered eating patterns are more prevalent in adolescent females than males May be linked with poor body image or low self-
esteem Teens often adopt unhealthy habits such as
Skipping meals Using food substitutes Taking diet pills or nutritional supplements Purging through vomiting, laxatives, or diuretics
Eating family meals promotes healthy eating patterns
ANOREXIA NERVOSA
Refusal to maintain body weight over a minimal normal weight.
Intense fear of gaining weight or becoming fat, even though underweight.
Denial of low body weight.
In females, absence of at least 3 consecutive menstrual cycles.
.
ANOREXIA NERVOSA:CLINICAL & LABORATORY FINDINGS
LANUGO and EDEMA of the skin, bradycardia and hypotension, constipation, normochromic anemia and leukopenia, hyponatremia, hypoglycemia, low hormonal levels (estrogen or testosterone, LSH, FSH) but normal TSH and increased cortisol
SKELETAL CHANGE: OSTEOPENIA
ANOREXIA NERVOSASIGNS OF MALNUTRITION :
Easy pinching in the posterior region of the arms, due to to loss of fat
Hollowing temporal muscles
Wasting of the tigh muscles
Easily plucked hairs
MEMO: the laboratory signs of malnutrition are HYPOALBUMINEMIA and HYPOPREALBUMINEMIA
TREATMENT FOR ANOREXIA NERVOSA
Close supervision Individual and family counseling Self-acceptance Time and patience Nutrition therapy
BULIMIA NERVOSA
Characterized episodes of binge eating alternating with purging
Female to male ratio 10:1
Some genetic factors may be involved, but and above all cultural attitudes toward standards of physical attractiveness
3 modalities are the most frequent:Self induced vomiting via “fingers” or ipecacAbuse laxatives (e.g. bisacodyl, cascara or senna)Misuse diuretics
In addition to diuretics also diet pills (containing ephedrine)
BULIMIA NERVOSA: COMPLICATIONS
Oral: loss of enamel of the anterior teeth and dental caries
GI tract: frequent vomiting can induce GE-reflux (occasionally tears in the esophagus). The abuse of laxatives can lead to constipation due to damage of the myo-enteric plexus
Abnormalities of the electrolytes: Metabolic alkalosis due to frequent vomiting HYPOKALEMIA present in 5% of the patients
BULIMIA NERVOSA: TREATMENT
Replenish potassium losses
Eventually I.V. fluids and lytes
Monitor lytes frequently
and, of course
Refer for psychiatric or psychologic counseling
TREATMENT FOR BULIMIA
Eating only at mealtime Portion control Close supervision after eating Psychological counseling
OBESITY:HEALTH CONSEQUENCES
Cardiovascular disease risk Type 2 diabetes (epidemic) Hypertension Orthopedic Sleep apnea Gall bladder
disease/steatohepatitis Psychosocial problems
BODY MASS INDEX
Weight in kg divided by height in m2
NORMAL BMI : 18 to 24 years of ageBMI < 18 : suspect malnutrition
BMI 24 to 30 : overweightBMI 30 to 40 : obesity
BMI above 40 = morbid obesity
OBESITY TREATMENTS
Caloric restrictions: restrict fats to less than 30% of the total caloric intake
Modification of lifestyle and exercise: A walk of 1 mile (1.5 m) burns 100 Kcal
Walk 2 - 3- or even 4 miles, 4 or 5x weekly, and add some resistance exercise 2 or 3 times weekly (all under some supervision).
The dietary variations: the high protein low carbohydrate (only 20 grams of CHO/day)
FINAL COMMENTS
The recipe for effective weight loss is a combination of: Motivation
Physical activity Caloric restriction
And all this with a lifelong adherenceBUT
MEMO: Prevention of weight gain is the first step EVEN IN CHILDREN