Nutrition - 8
Calcium Requirements for Adolescents
-Adequate intake of calcium is critical to ensure peak bone mass -Calcium absorption rate in females is highest around menarche and during early adolescence in males -About 4x more calcium absorbed during early adolescence compared to early adulthood -Peak bone mass is achieved at age (24 F, 26 M) -DRI for ages 9-18 = 1300 mg/day -Average intake is 865 mg F, 1130 mg M -Adolescents who do not include dairy should consume calcium-foritied foods -Soft drink consumption displaces nutrient-dense beverages such as milk and fortified juices
Dietary Intake and Adequacy among Adolescents
-Adolescents have very poor diets -Most have inadequate consumption of dairy, grains, fruits and vegetables! -Data from NHANES found adolescents' diets consist of 32% of calories from fat and 21% from added sugars
Nutritional Needs in a Time of Change
-Biological, psychosocial and cognitive changes affect nutritional status -Rapid growth increases nutrient needs -Desire for independence may cause adoption of health-compromising eating behaviors
Physical Growth and Development - Free Fat Mass
-Boys gain FFM at a greater rate for a longer period of time than girls post puberty -At ages 8-10 boys, on average, have 15% body fat and 24 kg of FFM At the end of puberty, ages 18-20 years, males have 12% body fat and 60 kg of FFM In contrast, girls have 20% BF and 24 kg FFM at age 8-10 years and about 26% BF at the end of puberty
Energy and Nutrient Requirements of Adolescents
-Energy and nutrient needs during adolescence exceed those of any other point in life -Needs correspond to physical maturation stage *Generally - males eat to build muscle and become masculine. Women eat to be attractive but also tend to enjoy eating more.
Folate Requirements for Adolescents
-Folate required for DNA, RNA and protein synthesis -DRI: 300 mcg for ages 9-13 and 400 mug for ages 14-18 -Folate added to fortified foods is better absorbed than folate from natural foods -Adequate folate intake for female adolescents reduces incidence of birth defects like spina bifida
Sociodemographic Moderators of Dietary Intake
-Gender, ethnicity, parental income and education affect diet quality in adolescents -Advertising and marketing of foods and beverages influences the food preferences, purchase requests, purchase and consumption of children and youth -The recent increase in adolescent overweight and obesity has brought the food environment in schools under increasing scrutiny
Iron Requirements for Adolescents
-Increased iron needs are related to rapid rate of linear growth, increase in blood volume and menarche in females -In females - iron needs are greatest after menarche -In males, iron needs greatest during growth spurt
Health Status of US Adolescents
-Increased overweight and obesity -Incidence of diabetes, hypertension, and hyperlipidemia in patients with CVD have been described as the "metabolic syndrome" -Iron deficiency in girls -Children are starting to smoke at a younger age -Adolescent pregnancy -Eating disorders
Iron and Adolescents
-Iron requirements increase during adolescents to meet the demands of growth and inevitable losses -Iron is lost from the GIT, skin, urine, and menstrual blood flow in females
Maturation and Growth of Males
-Males show great deal of variation in chronological age at which sexual maturation takes place -Peak velocity of linear growth occurs during SMR 4 & ends with appearance of facial hair at about age 14.4 -Linear growth continues throughout adolescence ceasing at about age 21
Maturation and Growth of Females
-Menarche (onset of first menstrual period) occurs 2-4 years after initial development of breast buds -Age of menarche ranges from 9-17 years -African American girls experience puberty earlier than Caucasians (by 8 years of age, 48% of AA girls are at SMR stage 2 versus 15% of Caucasians) -Peak linear growth occurs about 6-12 months prior to menarche -Severely restrive diets may delay or slow growth
Changes in Weight, Body Comp, and Skeletal Muscles in Males
-Peak Weight Gain = Coincides with timing of peak linear growth and peak muscle mass accumulation -During peak weight gain, there is a 20 pound weight gain per year -Body fat decreases about 12% -About half of bone mass is accused in adolescence
Changes in Weight, Body Comp, and Skeletal Muscles in Females
-Peak Weight Gain = Follows linear growth spurt by 3-6 months with a gain of about 18.3 pounds per year -Females experience a 44% increase in FFM and a 120% in FM -A level of 17% body fat is required for menarche to occur and 25% body fat needed to maintain normal menstrual cycles
Normal Physical Growth and Development
-Puberty occurs during early adolescence -Biological changes of puberty include: Sexual maturation Increases in height and weight Accumulation of skeletal mass Changes in body comp -The sequence of maturation events is consistent but great individual variation in age of maturation
Skipping Breakfast
1/5th of adolescents report skipping breakfast
Adolescence
A period of rapid linear growth, altered body composition, reproductive maturity and psychosocial development -Nutrient requirements are increased to meet these demands of growth and development -Significant gender differences
Normal Psychosocial Development
Adolescents develop -A sense of personal identity -Feelings of self-esteem or self-worth
Food Groups
Adolescents do not consume the recommended number of servings of fruits, vegetables and dairy products and they consume excessive amounts of added sugar, fat and saturated fat
School Wellness Policies
All school districts with a federally-funded school meals program must have a wellness policy that addresses nutrition and PA
Nutrient requirements for males and females until puberty
Are the same..
Sodium and Adolescents
Average daily sodium consumption has increased by approximately 1000 mg for adolescent boys and girls (NHANES 1971-1974 and 1999-2000)
Serving Size
Average serving sizes for foods eaten at home and away from home have increased during the past 30 years Foods frequently consumed by adolescents - salty snacks, ready to eat cereals, and soft drinks have significantly increased
Modifiable Risk Factors
Can delay the onset of a disease knowing that you have a predisposition. Having a well-balanced diet can prevent/delay the onset of medical predispositions
Carb, Fiber and Fat Requirements of Adolescents
Carbs: -130 g / day or 45-65% of calories Fiber: -AAP recommends 0.5g / kg body weight not to exceed 35 g Fat: -25-35% of calories from total fat. <10% calories from saturated fat
Family Meals
Decline during adolescence, but are an important factor in improving the nutritional quality of adolescent diets
Vitamin D
Dietary intake varies by ethnicity -Non hispanic caucasian have highest intakes of Vitamin D -African Americans have the lowest -Adolescent males are more likely to have adequate vitamin D intakes than females and older males Because the prevalence of lactose intolerance is higher among African Americans (75%) than Hispanics (53%) and Caucasians (6-22%) Avoidance of dairy products may explain the reduced Vitamin D intakes among African American adolesncets
Physical Growth and Development - Bone Mass
Doubles between the onset of puberty and young adulthood -Bone growth is greatest approximately 6 months after PHV -Approximately 25% of peak adult bone mass is acquired during the 2 years of peak adolescent skeletal growth
Physical Growth and Development - Fat mass
During adolescence, girls can FM at an average rate of 1.14kg/year In contrast, boys do not experience a significant increase in absolute FM
3 Periods of Psychosocial Development
Early Adolescence (11-14) Middle Adolescence (15-17) Late Adolescence (18-21)
Energy Requirements of Adolescents
Energy needs are influenced by: -Activity level -BMR (basal metabolic rate) -Pubertal growth and development Because males have greater increases in height, weight and lean body mass & higher BMR, they have a higher caloric need than females Level of PA declines during adolescence resulting in reduced energy requirements
Estimates of Iron Deficiency
FEMALES 9% of 12-15 year old 11% 15-19 year old MALES 5% of 12-15 year old 2% of 15-19%
Health and Eating-Related Behaviors during Adolescence
Factors affecting eating behaviors -Peer influence -Parental modeling -Food availability, preferences and cost -Personal and cultural beliefs -Mass media -Body image -Convenience
Metformin
Helps treat high blood sugar levels for those with Diabetes
Vitamin D and FDA
In 2003, the FDA approved Vitamin D fortification of calcium-foritifed juices and juice drinks African Americans and Mexican Americans who avoid dairy products may benefit from these fortified products. (Ex: 8 ounces of fortified organ juice provides up to 2.5 ug / 100 IU Vit D
Iron Deficiency in Adolescents
Iron Deficiency = -Determined by low serum iron, plasma ferritin and transferrin saturation -Often undiagnosed because of expense Iron-Deficiency Anemia = -Determined by simple and inexpensive hemoglobin or hematocrit levels -Indicates more advanced stage of iron deficiency
Percentage of Adolescents Meeting the Recommended Number of MyPyramid Servings
Male: Diary - 33% Fruits - 23% Vegetables - 35% Grains - 64% Meat - 50% Female: Dairy - 17% Fruits - 27% Vegetables - 34% Grains - 48% Meat - 17%
Fast Food Consumption
Most adolescents frequently eat meals and snacks away from home In one study, 26% of all meals and snacks were consumed away from home, accounting for 32% of total energy
Model Nutrition Program
Numerous innovative nutrition problems exist that promote nutrition to youth -One example is CANfit (California Adolescent Nutrition and Fitness)
Physical Growth and Development - Height
Peak Height Velocity -Spurt takes 2-4 years to complete and is generally longer in boys than girls The average height velocity is 5-6 cm/yr during adolescence ; peak velocity is 8-10 cm/yr Girls on average, begin their pubertal growth spurt at age 9 years and achieve their maximal rate of linear growth -Peak height velocity, occur at an average chronological age of 11.5 years
Adolescence Term
Period between 11 and 21 years -A time of profound biological, emotional, social and cognitive changes *Still need parental guidance to prepare for adulthood
Conceptual Model for Factors Influencing Eating Behavior of Adolescents
Picture 5
Age Specific Levels of Hemoglobin and Hematocrit
Picture 6
Community Involvement in Nutritionally Supportive Environments
Promoting lifelong healthy eating and PA behaviors among adolescents requires attention to multiple influences such as: -the community -home -school -media
Protein Requirements of Adolescents
Protein requirements influenced by protein needed: to main and build new FFM -DRI = .85 g / kg body weight Low protein intakes linked to: -Reductions in linear growth -Delays in sexual maturation -Reduced FFM
Calcium and Adolescents
Recent longitudinal data of bone mineral position suggest that calcium requirements may be higher -- 1500 mg for girls and 1700 mg for boys during calcium accretion
Sexual Maturation Ratings or "Tanner Stages"
SMR or "Tanner stages" = Scale of secondary sexual characteristics used to assess degree of pubertal maturation SMR 1 = Prepuburtal growth and development SMR 2 - 4 = Occurrences of puberty SMR 5 = Sexual maturation *These assess where the individuals are in the adolescent period
Puberty Term
Time frame during which the body matures from that of a child to an adult
Nutrient Intakes of Adolescents
US adolescents have inadequate intake of vitamins and minerals including: -Folate -Vitamins A, B6, C and E -Iron and Zinc -Magnesium -Phosphorus and Calcium
Selected Vitamin Requirements for Adolescents
Vitamin A - Deficiency rare among US adolescence Vitamin E = Estimated intake of <1/2 of daily needs (Nuts and seeds are a good source) Vitamin C - marginally adequate among adolescents (not bad, but still room for improvement)
Zinc Requirements for Adolescents
Zinc's importance during adolescence linked to: -Synthesis of DNA and protein -Its role in over 200 enzymes -Normal growth and sexual maturation Adolescents at risk for zinc deficiency: -Vegans -High fiber intake -Iron supplements
