PUBHLTH

macronutrients

carbs, lipids, proteins

micronutrients and last class of nutrients

vitamins, minerals. and water

carbs

ready source of energy, make up majority of calories, unrefined (whole) vs refined (edited)

protein

amino acids. Dietary proteins → broken down to amino acids → build body proteins from the AA available.

Body proteins

HETS: hormones, enzymes, transporters, structural

Digestive tract

proteins broken down to single AA, then enter blood, then body uses AA to build body pros

Lipids

Concentrated source of energy, adipose tissue is main storage site

types of dietary lipids

Triacylglycerides, saturated fatty acids, unsaturated fatty acids, cholesterol

Vitamins

help with bodily processes

minerals

regulatory and structural roles (bone strength, transport of oxygen, transmission of nerve pulses, muscle contractions)

Water

constantly turned over in the body. Lubricant, transporter, regulates body temp, structural component of cells, helps rid wastes

Public health issue

prevalent, serious, preventable/treatable

Discovery of nutrients

Scurvy experiments in 18th cent on sailors

nutrients - 1800s

daily recs developed to prevent or treat disease

nutrients - 1940s

shift from preventing infectious disease to preventing chronic disease

DRI - Dietary reference intakes

avg amount of energy/nutrients individuals should consume per day. accommodates age, conditions, sex.

EAR

estimate needs of populations. 50% in same sex and stage group

RDA

97% of pop. 2x standard deviation to EAR

UL

Max lvl of intake unlikely to pose toxicity

AI

used when not enough scientific evidence or high individual variability. Set by observational intake by healthy individuals in pop

EER

avg dietary energy intake to maintain energy balance

AMDR

percentage of total energy intake from macros. Decreased risk of chronic disease. 45-65 cal from carbs, 20-35 from fat, 10-35 from pros

DGA

report for health pros, secretaries of HHS and USDA appoint the committee every 5 years. current values protein, dairy and healthy fats, vegetables and fruits. grains, added sugar, ultra processed foods not valued

timeline of DGA

focus on kids (1900) → ration food (40s) → develop food groups (50s) → relate guidelines to health outcomes (70s) → quantitate certain nutrient recommendations (90s)

Fertility versus fecundity

actual production of children vs biological capacity

Factors that affect preconception

genetic disorders, environment, biological, age, behavioral

hormone imbalance affects

menstrual cycle, sperm production, preconception

undernutrition

10-15% below usual weight, decrease in estrogen, LH, FSH, and GnRH (fem) decrease in sperm viability and motility, testosterone (male)

Menarche

first period, 17% body fat minimum.

menstral cycle and BMI

22% body fat for stable menstrual cycle. BMI lower than 20 is bad (amenorrhea - no period for 3+ months)

female athlete triad

eating disorder, amenorrhea, osteoporosis. happens during peak of athletic performance

Osteoporosis (female athlete triad)

92% of bone mass dev by 18, less estrogen = abnormal bone turnover (estrogen inhibits osteoclasts)

clinical treatment for female athlete triad

1st goal is to get period back, then bone density (calcium and vitamin D)

overnutrition

more adipose tissue, abnormal hormones, no ovulation (anovulation). increased insulin production = decreased SHBG (accumulated testosterone in ovaries = anovulation)

types of fat

subcutaneous - under skin

visceral - around vital organs (insulin resistance = more visceral fat)

treatment

loss of 5-10% body weight = ovulation back, fertility increased.

Food folate

natural form of folic acid. Polyglutamate req enzymatic activity to get to absorbable form so less absorbable

folic acid

synthetic. monoglutamate increases bioavailability, passively diffused thru small intestine to blood, more absorbable.

spinal cord development

folate needed for synthesis of DNA + cell division. First 21 days lots of cell division, CNS and heart made and spinal cord closed

Spina Bifida

improper closure of spinal cord

Preconception and folate

folate intake prevents neural tube defects. good for synthesis of DNA and cell division and dna methylation

NTD Varies (hispanics)

lower awareness of folate, don’t use supplements, higher rate of polymorphism in MTHFR (gene encoding enzy for folate metabolism), corn flour vs wheat flour

conception and implantation

egg fertilized by sperm → single cell zygote forms → travels along fallopian tube and single cell divides → blastocyte forms and implants into uterine wall

embryonic period

rudimentary organs formed, historophic nutrition exchange by uterine glands and arteries.

uterine glands

secrete nutrients, growth factors, cytokines into uterine capillaries/arteries

fetal period - amniotic sac

source of fluid

fetal period - placenta

exchanges nutrients and oxygen between mom and baby by umbilical cord inside, waste elimination, hormone production, immune function

hormone production in placenta during pregnancy

estrogen - growth of breasts and uterus. enhanced nutrient absorbtion

hCG - prevents rejection of placenta

progesterone - muscle relaxation and prevents pre-term

hPL - homeostasis

what happens at 30 weeks in pregnancy?

fetal energy demands at peak

blood changes in pregnancy

volume increases 30-50%, increase in red blood cell production, increase vacular capacity for exchange

digestive tract changes in pregnancy

hormone relaxation. Gastric emptying slows + increased intra-abdominal pressure = nausea. Sphincter relaxation + pressure = heartburn

weight gain in pregnancy

normal: 25-35 lbs. underweight: 28-40lbs. overweight: 15-25lbs. obsese: 15lbs. fetus represents 25%

energy recommendations in pregnancy

1st tri: don’t add cals

2nd tri: +300 cals

3rd tri: +450 cals

what is the main fuel source for fetus

glucose (carbs)

Insulin resistance during pregnancy

hPL blocks insulin receptors, stopping glucose and increasing liver glucose. Leads to increased production of fetal insulin to rapidly utilize glucose.

carbs and proteins recommendations in pregnancy

carbs: 175 (normally 130)

protein: 1st = 46, rest = 71. (normally 46)

cholesterol in pregnancy

needed for estrogen and progesterone, cell and nerve membrane development in fetus

essential fatty acids in pregnancy

omega-6 (arachadonic acid) and 3 (EPA and DHA), immunity, eye and neural development of fetus

Visceral fat in pregnancy

more = higher chance of pregnancy disorders = c-section, child too large or small, stillbirth, obesity

gestational diabetes mellitus

glucose intolerance during pregnancy. glucose levels remain high in circulation. if happens in one pregnancy will happen in another. screened in 2nd trimester by blood draw.

untreated gestational diabetes mellitus

large baby as increased blood glucose taken up by placenta, c-section or preterm, type 2 diabetes in child, obesity, shoulder dystocia, pre-eclampsia

micronutrients in pregnancy

growth, development, maintenance, energy utilization, protein synthesis, bone mineralization

calcium in pregnancy

bone mineralization of fetus. constriction of blood vessel. nerve conduction. muscle contractions. hormone signaling. most needed in 3rd tri

if calcium is low in diet during pregnancy

bone will release calcium to maintain blood levels

lead in pregnancy

can be released instead of calcium. 3rd trimester. not good. can be in objects and food/water. Flint water crisis.

vitamin D in pregnancy

for calcium and phosphorus. sunlight. no change in daily recc from when not preg

iron in pregnancy

high need to support hemoglobin structure. Iron deficiency common. causes low birth weight and anemia in infant.

Prenatal iron recommendations

1st: no increase

2nd + 3rd: 27mg per day. 47 if vegetarian

DNA Methylation

methyl groups on DNA dictates gene expression. more methylation = decreased expression.

choline in pregnancy

more made in pregnancy. good for synthesis of neurotransmitters in embryonic and late fetal period, structural and functional component of all cells, role in DNA methylation

epigenetics

study of changes in gene function that occur without a change in the sequence of nuclear DNA

adolescent pregnancy

growth for 4-7 years after menarche, pregnancy adds stress so more likely to get hypertension, anemia, weight gain. pregnancy starts with poor nutrient status and there is competition between mom and fetus.

Cephalopelvic disproportion

baby head and birthing parent’s pelvic region are disproportionate, requires c-section

older pregnancy

pre-existing health problems, chromosomal abnormalities more common bc cellular division bad in aging eggs. down syndrome and autism high. higher chance of twins.

Twins in pregnancy

weight gain is MUCH higher. energy needs are higher. pregnancy is shorter

Timing for pregnancy

18 months or more recommend. less comes with risks

Alcohol during pregnancy

freely passes thru placenta, slows metabolism, immature enzymes. many disorders due to exposure (FAS, birth defects, neurodevelopmental disorder)

Bisphenol A (BPA)

interferes with hormone systems, comes from canned foods, water bottles, food containers, etc. causes obesity, type 2 diabetes, early on set puberty, autism, hyperactivity.

mercury

why pregnant women can only eat 2-3 servings of fish. Passes placenta to fetus and causes hearing loss, seizures, cognitive developmental disabilities. Accumulates in maternal tissue.

aromatase

enzyme active in adipose tissue that can disrupt normal reproductive hormone status