Week 1 Intro and Nutritional Studies

Question 1

Nutrient Interaction

Answer 1

Maintenance, growth, reproduction and health/disease
> Absorption, assimilation, biosynthesis and catabolism
> Cardiovascular disease, cancer, etc
> Hunger (drive); appetite (psychological influences without hunger)
> Phyto- (ellagic acid, catechins) and zoo-chemicals (sphingolipids) are physically active but NOT essential diet nutrients (can be made by body; no DRI, not needed in abundance)

Question 2

Studies of Nutritional Questions

Answer 2

1. Epidemiological: Study of diseases in population
2. Case-Control: disease vs control groups studied with best results emerging from highest possible matching of confounding conditions

Question 3

Observational Studies

Answer 3

1. Cross-sectional: Different populations at a single point in time compared
2. Longitudinal: observational of same subjects over time
   > Cross-over study: subjects receive a sequence of different treatments
3. Prospective: risks/protection factors –> disease outcome in cohort of subjects (longitudinal)
   > Cohort: group that shares defining characteristics (occupation, birth, graduation)
   > Ex. Nurses Health Study (NHS): examine epidemiology and effect of multiple factors in nurse’s work-life on disease development
   > JAMA report of NHS: incidence of CHD/weight change in women –> high BMI positively correlates with # of non-fatal MI
   > Disadvantage: time-consuming, need to follow large # of subjects, not good for diseases with long latency
4. Retrospective: Outcome –> risks
   > Disadvantage: poor model for rare disease, absence of data on confounding factors; bias

**Both P and R allow clarify of temporal sequence, calculation of incidence, and examination of multiple effects of a single exposure

Question 4

Experiments

Answer 4

1. Animal: well-characterized organisms can give good info about complex questions
2. Human: must be examined in human context only
   * *Best with Double-blind: no one knows which group is receiving which treatment.

Question 5

Energy Values of Foods

Answer 5

1. calorie: heat it takes to raise 1g of H2O by 1 Celcius (usually in kcal; Calorie is 1000g of water
   > Carbs (4 kcal/g), Protein (4), Fat (9), Alcohol (7)
2. Dietary Reference Intakes (DRI):
   > EARs: Estimated Average Requirements (50% population have inadequate intake)
   > RDAs: Recommended Dietary Allowance (2-3% pop inadequate)
   > UL: Upper Level (highest nutrient intake w/o adverse risks)
   >AI (adequate intake): RDA~UL intake has almost 0% inadequacy/adverse effect risk (covers the need of 97-98% individuals)
   **AI daily intakes for which there are insufficient research data for EAR

Question 6

Daily Values (DV)

Answer 6

DRI recommendations are age-, gender, and life stage specific (too much information for nutrition facts label), so FDA created one number for daily requirement of each nutrient in 2000 calorie diet

Question 7

Energy-yielding Nutrients (Macros)

Answer 7

1. Carbs (glucose)
2. Lipids (linoleic acid/Omega-6 and a-linolenic acid/Omega-3)
3. Proteins (AA): Histidine, isoleucine, leucine, lysine, methionine, phenylalanine, valine, trptophan, threonine
4. Water

Question 8

Non-energy yielding Nutrients (Micros)

Answer 8

1. Water-soluble Vitamins: Thiamin, Riboflavin, Niacin, B6/B12, C, Folate
2. Fat-soluble Vitamins: A/D/E/K
3. Minerals: Ca, Cl, Mg, P, K, Na, S (minor: Cu, F, I, Mn, Zn)