Lifecycle Nutrition - Pregnancy & Lactation
How should a woman prepare before becoming pregnant?
- because nutrition can affect her ability to actually become pregnant, she should:
- 1. achieve/maintain a healthy body weight
- 2. follow an adequate/balanced diet
- 3. be physically active
- 4. receive regular medical care
- 5. manage chronic conditions
- 6. avoid harmful influences
How should a man prepare before trying to get a woman pregnant?
- 1. achieve/maintain a healthy body weight: a higher BMI is correlated w/ low sperm count
- 2. have adequate zinc, which plays a role in testosterone production & DNA (sperm) replication
- 3. have enough antioxidants to keep sperm healthy (contain lots of PUFAs which can spoil easily but is prevented by antioxidants)
- 4. minimize alcohol intake: lots of alcohol can lower sperm count
What is the single best predictor of an infant's health?
- its birthweight
- women should NOT diet during pregnancy: may deprive fetus of critical nutrients
- women must gain some but not too much weight during pregnancy; women who don't gain enough weight OR who gain too much put the baby at risk for health complications
Weight Associated Risks
- Underweight Moms have an increased risk of preterm births & infant death
- Overweight Moms have an increased risk of complications DURING birth & health complications for infant after birth
When is weight gain during a pregnancy most critical & why?
- during the 2nd & 3rd trimester
- brain development occurs in the last (3rd) trimester
What were weight gain recommendations for women prior to 1970 & what was the reasoning behind such recommendations?
- 10-14 lbs
- a small amount of weight gain was recommended because it was noted that large weight increases were associated with preeclampsia
- *this weight was actually coming from EDEMA
- after 1970 the recommendation was increased to 20-25 lbs
What weight gain recommendations did the Institute of Medicine (IOM) set for women in 1990?
- they based weight gain on a womans weight (BMI) prior to pregnancy
- those who weigh more should gain less
- those who weigh less should gain more
- the recommendation was DEVELOPED b/c of concern about low birth weight (LBW) infants
- it aimed to PREVENT premature births & small for gestational age (SGA) infants
Why did the IOM reexamine the weight during pregnancy guidelines in 2009?
to include a new category addressing pre-pregnancy obesity
IOM Pregnancy Weight Gain Guidelines
- Underweight Women (<18.5) → gain 28-40 lbs
- Normal weight Women (18.5-24.9) → 25-35 lbs
- Overweight Women (25-29.9) → 15-25 lbs
- Obese Women (>30) → 11-20 lbs
- only ~1/3 of women stay within these ranges; vast majority gain more weight
What happens to the Basal Metabolic Rate (BMR) during the 1st trimester of pregnancy?
- it SLOWS DOWN, which is why weight gain isn't recommended until the 2nd & 3rd trimesters
- all women except obese ones should gain ~4.4 pounds during the 1st trimester
- WEEKLY weight gain changes in the 2nd & 3rd trimester: .5-1 lbs depending on BMI
Where is the weight that's gained during pregnancy distributed?
- 1. fetus: 25-27% (only 1/4 of the weight gain goes to baby)
- 2. fat stores: 25-27%
- 3. extra fluid: 13%
- 4. uterus & breast growth: 11%
- 5. expanded blood volume: 10%
- 6. amniotic fluid: 6%
- 7. placenta: 5%
Critical Periods in Pregnancy
- times of intense development & rapid cell division in the fetus
- if cell division & development is compromised, it may be impossible for the baby to develop the structures & functions at all
- oran & tissue development (esp during the 1st trimester) are the most vulnerable to adverse influences such as deficiencies, toxicities, or teratogens during critical periods
- or developmental plasticity: persisting changes in the body structure & function can be caused by environmental stimuli (especially NUTRITION)
- genes can express different ranges of physiological or morphological states in response to environmental conditions during fetal development
- explains how the groundwork for chronic diseases can originate if the fetus is exposed to adverse influences during critical periods of fetal development
- such changes can potentially influence successive generations
Dutch Famine/Hunger Winter
- a famine in the German-occupied western part of the Netherlands during the winter of 1944-1945
- a German blockade cut off food & fuel shipments to punish the Dutch for not aiding Nazi war efforts
Famine Exposure during EARLY Gestation
- birth weights were normal (DIDN'T decrease)
- offspring had elevated rates of obesity, altered lipid profiles, & cardiovascular disease
- females born to mothers during this time who went on to give birth had babies with LOW birth weights
Famine Exposure during LATE Gestation
- babies had low birth weights & continued to be small people throughout their lives
- had lower rates of obesity as adults
- females born to mothers during this time who went on to give birth had babies with NORMAL birth weights
- *don't see the same tie to chronic disease as observed with early exposure to starvation
When are energy & nutrient needs generally highest during the lifecycle?
- during LACTATION & PREGNANCY needs tend to be higher than any other time in ADULT life
- order: lactation > pregnancy > infancy
- BMR increases during the 2nd & 3rd trimester after slowing down in the 1st
- food intake should increase by ~15-20% during pregnancy
What are the calorie modifications for each trimester of pregnancy?
- 1st: NO extra calories (or a few)
- 2nd: 340 more kcals/day
- 3rd: 450 kcals/day
What is the RDA for protein during pregnancy?
an additional 25 g/day
Fluid Intake During Pregnancy
- fluid needs RISE to 3 Liters/day to help increase maternal blood volume, regulate body temperature, produce amniotic fluid to protect the fetus, combat constipation, & reduce risk of UTIs
- + dehydration is a large cause of premature labor
- embryo's precursor to the CNS (brain & spinal cord)
- it closes by 18-26 days after conception
- defects (NTD) such as anencephaly or spinal bifida are caused by failure of the tube to close or failure for it to close completely
What role does folate intake & supplementation play in pregnancy?
- supplementation of 400-600 micrograms/day & intake of 200-300 micrograms/day during the PERICONCEPTUAL period reduces risk of NTD
- there is an increased need in pregnancy due to erythropoiesis (process by which RBCs are made)
- was added to cereal grains in 1998 & reduced NTD by 28% in the US & 46% in Canada
- failure of spinal chord to close
- is characterized at birth by an opening in upper part of the spinal chord
absence or failure to develop a brain
What two micronutrients are needed during pregnancy for fetal bone development?
Calcium during pregnancy
- the RDA of Ca2+ does NOT increase b/c maternal absorption of Ca2+ increases during pregnancy (more doesn't need to be consumed)
- if required Ca2+ intake is not met, the fetus gets it at the expense of the mother's bones; the mother suffers bone loss
- RDA: 1000-1300 mg/day
Vitamin D during pregnancy
- the RDA of vitamin D does NOT increase
- RDA: 600 IU/day
- a deficiency interferes w/ calcium metabolism
What two micronutrients are needed during pregnancy for fetal blood production & cell growth?
Iron during pregnancy
- the RDA of iron DOES go up to increase blood volume, fetal needs, & compensate for blood loss during delivery
- even though maternal & baby absorption of iron also increases during pregnancy
- RDA: 18-27 mg/day
How long after being born does the maternal supply of iron last for an infant?
- 6 months
- after 6 months an iron source needs to be given to the baby because breast milk is low is iron
- AAP recommends supplementing iron at 4 months for breastfed infants
- a mother's iron stores are transferred to the fetus during the 3rd trimester
Zinc during pregnancy
- the RDA of zinc DOES increase to facilitate DNA, RNA, & protein synthesis and "cell development"
- low levels increase absorption & excess can be toxic to the fetus
- RDA: 8-11 mg/day
What are low levels of zinc during pregnancy associated with?
- 1. preeclampsia - pregnancy induced hypertension
- 2. decreased cell mediated immunity (T cell immune responses)
Iodine during pregnancy
- the RDA of iodine increases - can be obtained from iodized salt
- mental retardation due to cretinism is entirely preventable using iodine supplementation during pregnancy
- mental retardation due to cretinism = single largest cause of mental retardation
a condition of severely stunted physical & mental growth due to untreated congenital deficiency of thyroid hormones (hypothyroidism) usually due to maternal hypothyroidism
What micronutrients need to be increased DURING pregnancy?
- IRON, Zinc, & Iodine
- calcium, vitamin C, & vitamin D levels remain unchanged
Vitamin A during pregnancy
- megadoses/excess vitamin A leads to fetal malformation, especially in the central nervous system
- prior to 7 WEEKS such excess (eg. acutane) would be most damaging
- intake during pregnancy increases the rate of miscarriage, fetal death, or limited fetal growth
- should limit intake to one coffee or 2 sodas a day; no more than 200mg should be consumed
What substances may pose risk to the fetus?
- Vitamin A
- Sugar Substitutes, especially saccharine (exception of diabetics)
Alcohol during Pregnancy
- a teratogen that crosses the placenta associated w/ various birth defects, delivery complications, sudden infant death syndrome, & increased risk of miscarriage
- FAS (fetal alcohol syndrome): characteristics associated w/ prenatal exposure to high quantities of alcohol [developmental/learning disabilities + facial, limb, & heart malformations]
What micronutrients should pregnant vegetarians be aware of? Vegans?
- vegetarians: should take Iron supplement
- vegans: vitamin B12, Iron, Ca2+, vitamin D
- are able to meet most nutrient needs through diet only
Vitamin B12 Deficiency in Infancy
- a vitamin B12 deficiency during pregnancy can result in fetal spinal cord damage & psychomotor retardation
- if deficiency is recognized providing vitamin B12 after birth can correct the damage, however preventing the deficiency is preferred
Common Pregnancy Concerns
- 1. Nausea: caused by hormone changes oftentimes more during 1st trimester
- 2. Constipation & Hemorrhoids: related to slowing of digestion in GI tract (can treat w/ fluid and fiber)
- 3. Heartburn: caused by fetus' physical presence pushing on internal organs
- 4. Food Cravings/Aversions: caused by hormone changes
- 5. Pica: nonfood cravings, often a side-effect of dietary anemia
What foods should be avoided during pregnancy & why?
- *pregnant women are essentially immunosuppressed so are at higher risk for getting food-born illnesses (eg. Listeria)
- hot dogs or deli meat (unless STEAMING)
- smoked seafood (unless FULLY COOKED)
- meat spreads/pâté
- unpasteurized milk & cheese (brie, feta, blue, mexican cheeses)
- more common to tell pregnant woman what NOT to eat than what to eat (b/c of time)
What high mercury foods should be AVOIDED during pregnancy?
- Swordfish, Shark, King mackerel, White Canned Tuna, Tilefish (golden snapper or bass)
- these fish are high mercury b/c they're large fish that consume OTHER fish, compounding their mercury content
- it's okay to eat ~12 oz. a week of shrimp, salmon, pollock, catfish or ~6 oz. of LIGHT canned tuna (smaller fish)
- production of breast milk suppressed by estrogen/progesterone until childbirth
- oxytocin: responsible for milk "let-down"
- prolactin: responsible for milk synthesis
- colostrum: 1st milk produced right after birth [yellowish, thick, clear] high in PROTEIN, antibodies, vitamins, & minerals
- energy & protein needs are higher than in pregnancy for mother
- iron & folate needs are lower during lactation than in pregnancy; other vitamin & mineral requirements stay ~same
- lots of water intake is required
- alcohol, drugs, smoking, excess caffeine should all be avoided while breastfeeding
Iron Needs Throughout Female Lifecycle
- normal → pregnancy → lactation
- 11mg 18-27 mg 8mg
- iron needs decrease during lactation because woman isn't menstruating
How many kcals/day does milk production require? How many extra kcals/day are lactating women RECOMMENDED to consume during lactation?
breast milk production takes 700-800 kcals/day but women are only recommended to consume an extra 300-400 kcals/day (depending on how long after they've given birth) to help facilitate weight loss after pregnancy
Benefits of Breastfeeding for Infant
- it's nutritionally superior to formula
- is always sterile & fresh
- contains immunoglobins
- is more digestible
- reduces the risk of respiratory, GI, & ear infections
- reduces the likelihood of overfeeding (infant controlled process)
- promotes mouth/jaw development
- provides omega-3 FAs
- reduces the risk of SIDS, diabetes mellitus (DM), food allergies, & asthma
Benefits of Breastfeeding for Mother
- enhances recovery of uterus size
- decreases post partum bleeding (conserving iron stores)
- it's more convenient/economical (free!)
- triggers hormones that help return internal organs to original state
- decreases the risk of breast + ovarian cancer
- delays ovulation (natural BC)
- increases E expenditure facilitating weight loss
specific situation in which a drug, procedure, or surgery should not be used because it may be harmful to the patient
Contraindications to Breastfeeding
- HIV (in the US but not 3rd world countries w/ poor water supply; it can be passed through breast milk)
- Metabolism Issues/Allergies in Child (eg. galactosemia is a component in breast milk; if child can't metabolize or is allergic a special formula needs to be given)
- Lifestyle Practices (alcohol, drugs, smoking, environmental contaminants, caffeine)
How long should infants EXCLUSIVELY breastfeed? Breastfeed in general?
- infants should exclusively breastfeed for 6 months
- infants should be breastfed for at least 12 months
*What happens to breast milk if a lactating mother has poor nutrition or intake?
- the QUANTITY of breast milk is reduced, NEVER the quality of the milk (her body just won't produce enough)
- the body will never make poor quality breast milk
- has 20 cal/oz.
- contains more whey than casein (70:30) b/c whey is more easily digested
- composition of milk changes DURING a feeding
- 1st = foremilk: sweeter, higher in lactose
- 2nd = hindmilk: designed to satiate the infant, hold them over until next feeding
- the milk is not a good source of iron but contains a small amount, the absorption of which is facilitated by lactose & vitamin C
What are common problems associated with breast feeding?
sore nipples, letdown failure, overactive letdown, engorgement, plugged duct, mastitis
What are some components of formula feeding?
- infants are MORE LIKELY to be overfed w/ formula
- need to make sure it's safely prepared
- it's easier to tell how much the infant is getting
- the father (pshh) can be more involved
- may require fewer feedings (takes longer to digest)
- can iNTERFERE with breastfeeding (nipple confusion)
Lifecycle Nutrition - Infancy, Childhood, Adolescence
What are the most reliable markers of infants health status 1. after birth & 2. during infancy?
- after birth: birth WEIGHT
- during infancy: growth (& development) - way to measure if a child is well-nourished & healthy
What are the 2 main types of growth charts?
- 1. WHO growth standards: used to monitor growth for infants & children ages 0-2
- 2. CDC growth charts: used for children ages 2+
- *growth charts are the primary tool in detecting changes in growth & normal development
- 50th percentile is "normal"
What do growth charts between birth & 36 months (3 years) measure?
- height for age
- weight for age
- weight for height
- head circumference for age
What do growth charts between 2 & 20 years measure?
- height for age
- weight for age
- BMI for age (*different from straight BMI)
What information do growth charts provide when plotted correctly?
- information about a child's growth pattern
- gestational age, birth weight, parental stature, & nutritional status may influence growth patterns
Why are we not concerned about an infant losing weight soon after birth?
- because it's normal to drop weight after birth
- it's usually associated with fluid shifts associated with the trauma of birth
- should be regained in ~the 2 weeks after birth
At what age will most children double their birth weight?
- 4-6 months of age
- triple their birth weight by 12 months
- QUADRUPLE birth weight by 2 years!
- weight is the 1st measure affected by inadequate nutrition
- a drop to a lower percentile in weight is usually an indication of some disruption in the child's expected growth
What is the most difficult measurement to obtain accurately in infants & small children?
What should happen to a child's height (length) by 12 months?
- it should INCREASE by 50% percent
- weight is affected before height
- height will be maintained at the expense of weight
- if height is affected/drops (stunting) that is indicative of a more long-term ailment
Order of structures maintained during chronic poor nutrition
- 1. brain circumference: will be maintained at all costs (LEAST sensitive)
- 2. height: will go after weight has been compromised
- 3. weight: the 1st characteristic affected by malnutrition (MOST sensitive)
- *once head circumference for age once impacted will lead to irreversible poor developmental outcome
Underweight [being small]
- an abnormally low weight for age
- can be caused by a recent illness or trauma (eg. rhodavirus)
- once recovered can generally catch up
- can also be caused by genetic or ethnic differences
Wasting [becoming small]
- an abnormally low weight for height
- a child has a certain height but a low weight FOR that height
- caused by acute, prolonged inadequate intake
- wasting is correlated with mortality
- an abnormally low height for age
- but the weight for length value is normal
- caused by chronic inadequate intake or genetic/ethnic differences
- the child will be unable to reach a height they should have reached genetically
How many kcals/kg/day do infants require?
- 100 kcals/kg/day (compared to 25-35 kcals/kg/day for adults)
- energy needs are extremely high for infants
- protein: 2 kcals/kg/day (compared to .8 kcals/kg/day for adults)
- fat: 40% of calories should be from fat (making CNS)
- also have high fluid needs but that can come from breast milk/formula; exogenous water isn't required
Is a multivitamin recommended for the 1st year of life? What is needed?
- Vitamin K injection given at birth to prevent hemorrhage & establish gut flora
- Vitamin D supplementation should be given to breastfed infants (formula has it)
When can solid foods be introduced to an infants diet?
- ~4-6 months old
- recommended 1st food = iron fortified rice, wheat, or barley
- at this age an infant has increased digestive enzymes, loss of extrusion reflex, & increased musculature to sit upright
What might occur if solid food is introduced before the infant is 4 months old?
How should NEW foods be introduced to an infant?
- ONE food at a time so that their reaction can be tracked
- ~1 new food every 3 days
- NO milk during the 1st year of life → GI bleeding
- NO honey/corn syrup → increased botulism risk
- introducing challenging textures improved oral-motor skills
Baby Bottle Tooth Decay (Early Childhood Caries)
- when babies/toddlers are allowed to have a bottle in their mouth for extended period of time, their teeth are bathed in the carbohydrate-rich formula or breast milk, causing tooth decay
- sugar + oral bacteria → acid acid + teeth = decay
- to prevent the bottle should be removed when the baby is done feeding
- causes immature dentition, plaque filled mouth, low saliva, & contributes to childhood obesity
Risks at Infancy
- Colic (crying often tied with poor eating)
- Iron deficiency anemia
- Gastroesophageal reflux
- Diarrhea (often due to juice, has a high osmotic load)
- Failure to thrive
Failure to Thrive (FTT)
- infants & children who lose weight or fail to gain weight in accordance with standardized growth charts
- inadequate physical growth
- inability to maintain expected growth over time
- often identified in the 1st 3 years of a child's life
Organic Failure to Thrive
refers to a child with an underlying medical condition that contributes to poor growth
Non-organic Failure to Thrive
refers to a child who is younger than 5 years of age and has no known medical condition that causes poor growth
What is notably seen in a child's appetite at age 1?
- a marked DECREASE in appetite
- this is because their growth rate slows quite significantly
- caretakers determine WHAT & WHEN children eat, but children decide IF & HOW MUCH they eat
FITS (Feeding Infants & Toddlers Study)
- a comprehensive survey conducted over the phone assessing food & nutrient intakes of over 3,000 infants & toddlers (up to age 3) by asking for a 24 hour diet recall
- showed that fruit/vegetable intake was limited
- older infants didn't get adequate iron & zinc
- the UL for sodium was EXCEEDED
- 80% of preschoolers (2-3 y/o) consumed nutrient poor energy dense drinks (soda/juice), desserts, & snacks dAILY
Nutrient needs during childhood (ages 4+)
- energy & protein needs DECREASE from those of infancy
- getting micronutrients from regular food now - variety is necessary
childhood growth chart interpretations
How does childhood obesity affect growth?
- obese children begin puberty earlier
- they tend to be shorter than their peers
- they have more bone & muscle mass
- it's important to check their lipid profile, for type 2 diabetes, & respiratory disease
What is the most effective way to deal with childhood obesity?
- prevent it…
- want to reduce their weight gain as opposed to have them lose weight
- encourage physical activity (at least 1 hr. a day)
- have their parents set a GOOD example
- sugar sweetened beverage; soda, juice, any drink that has calories
- "the only drink with calories someone at risk for metabolic syndrome should be consuming is milk"
- girls: 10-11 years old - gain ~6 in. in height, 35 lbs. in weight
- boys: 12-13 years old - gain ~8 in. in height, 45 lbs. in weight
- increase in calorie/protein needs after childhood
in adolescence mainly due to hormonal changes as opposed to food intake, which it's often incorrectly linked to
- red flag: vegetarianism for early teen girls; a socially acceptable way to restrict food intake
- anorexia, bulimia (classic presentation is slightly overweight), binge eating (most common), & eating disorder NOS (not otherwise specified)
- disordered eating: eg. disliking food touching on plate
Female Athlete Triad
- disordered eating (usually via a restricted diet) & inadequate intake of energy can lead to amenorrhea
- loss of a period changes hormonal status
- poor intake & no period can cause osteoporosis
- end result: potential long-term poor bone status, short-term poor health status
Lifecycle Nutrition - Older Adulthood
What are some old-age related changes?
- weight & body composition (add fat, lost lean mass, sarcopenia)
- reduced muscle & skeletal strength
- *FEWER calories are needed*
- decline in immune defense mechanisms (can contribute to chronic inflammation)
- decline in taste, smell, vision, mobility, hearing
- loss of Ca2+ & decreased BONE density
- decreased vitamin D synthesis (& intake)
- reduced thirst response & dry mouth
- Xerostomia - lack of saliva
- Atrophic Gastritis
- Reduced GI motility
- age-related degenerative loss of skeletal muscle mass, quality, & strength
- mediated by pro-inflammatory cytokines, growth hormone secretion, & input from a CNS that has fewer motor neurons
What is the ideal diet for an older individual?
- maximally nutrient dense but moderate in calories
- percentages of CHO, fat, & protein stay the same but FIBER recommendations are lower b/c they're based on calorie needs (which are decreasing)
How do micronutrient requirements for older adults change?
- Ca2+ increases: it's less well absorbed (atrophic gastritis)
- Vitamin D increases: needed for Ca2+ balance
- Iron needs decrease: no longer monthly female losses
- *Zinc should be adequate: maintain immune function & the senses
- Vitamin A should stay the same
- Vitamin B12 should be adequate
How is vitamin B12 absorbed?
- in food B12 is protein bound - must be separated in order for absorption to occur; this is done via 2 mechanisms in the stomach
- 1. gastric acid
- 2. protease enzymes (eg. pepsin)
- *often older adults have less stomach acid, compromising B12 absorption
Concerns of Mature Adults?
- 1. drug-drug & drug-nutrient interactions
- 2. depression
- 3. anorexia of aging
- 4. arthritis
- 5. bowel & bladder regulation
- 6. dental health
- 7. osteoporosis
- 8. Alzheimer's
How does poor oral health affect nutritional status?
- food is HARD to chew & swallow - soft foods are preferred leaving less variety available
- overall can lead to a decreased desire & ability to eat
What is a major risk factor for choking & malnutrition in old age?
- can't track food because tongue can't feel palate
- false palate prevents sensing of food via tongue
Age Related Macular Degeneration
- a hole in the central part of vision
- risk factors include age, smoking, & family history
- may be reduced by antioxidants or lutein & zeaxanthin (can also reduce risk of cataracts)
- if overweight lutein & zeaxanthin tend to deposit in body fat as opposed to macula where it can be protective
What are the strongest independent predictors of macular pigment density?
- 1. dietary lutein
- 2. diabetes
- 3. BMI
- 4. waist to hip ratio
How many older adults are malnourished?
- 1 in 6
- b/c of that there's a specific nutrition screening initiative called DETERMINE