FSHN 3610: Exam 1

Healthy Eating Index

measure of diet quality based on adherence to US dietary guidelines

• Score 0-100

• <50 = poor

• 50 – 80 = allows improvement

• >80 = good

DASH diet

focused on fruits, veggies, whole grains, & low-fat dairy products that correlated with decreased BP

Mediterranean diet

recommended for treatment of multiple chronic diseases emphasizing whole fruits, veggies, grains & food sources of omega-3 FAs.

Dietary Reference Intake

umbrella for other standards, helps to prevent nutrient deficiency

Dietary guidelines

general

MyPlate/Pyramid

food choices

Daily Values

number values

Objective method

direct observation; laboratory setting

Subjective method

self-reporting; relies on personal experiences, knowledge, & memory

• 24 hr recall

• Food records/diaries/logs

• Food frequency questionares (FFQ)

• Screeners

Measurement error

difference between the true value of a parameter & the value obtained from the reported dietary intake

Random error

variability of intake (collecting multiple days worth of dietary data decrease this)

Systematic errors

1. Respondent biases: underreporting, overreporting, underestimating portions

2. Interviewer biases: assumptions, leading questions

24 hr recall

Food & beverages consumed in previous 24 hr period, quick & easy.

Dietary record/log/diaries

foods & beverages consumer over 3- to 7- day period.

Food Frequency Questionare (FFQ)

foods & amts consumer over long period of time

• Evaluate intake of specific nutrients

•  Not useful for assessment of: dietary patterns, content of meals & snacks

• Combined w/ 24 hr recall is a more comprehensive assessment

Techonology

diet apps & smart phones can record food intake for nutrient analysis

• Digital photography of food intake

Screener

 focus on specific foods, food groups, nutrients or other targeted aspects of diet

• Brief diet assessment instruments

Multiple pass method

 used to improve dietary intake collection, reduce errors. 

• 24 hr recall

Steps (passes)

1. Quick list, no questions

2. Forgotten foods

3. Time & location

4. Details, how was it prepared, portions, etc.

5. Final probe

Biomarkers

can be used to validate dietary intake methods.

• Doubly labeled water (DLW): avg energy expenditure over 2 wk period.

• Other biomarkers:

  • Urinary N, Sodium, Potassium

  • Urinary fruc, sucr

Observational

cohort, cross-sectional.

• Measure nutrient intake

• Longitudinal studies

Experimental

 RCT.

• Treatment, intervention, or program → measure & observe

Factors Impacting Methods Section

• Study goal

• Funding

• Human resources

• Participant population

• Labor intensity

Nutrition Care Criteria

Energy & protein req

Indirect calorimetry

determines energy expenditure by measuring a subject’s oxygen consumption, CO₂ production, & minute ventilation (amt of time subject breathes in 1 min)

3 Components for Total Amount of Energy Req by an Individual

1. Basal Energy Expenditure (BEE) or Basal Metabolic Rate (BMR)

2. Energy for Physical Activity (PA): 15-20% energy req

3. Thermic Effect of Food (TEF): 10% of caloric intake

** = Total Energy Expenditure

Basal Energy Expenditure (BEE)

energy used for physiological functions that maintain life.

• E.g. respiration & heartbeat

• measured by: O consumed by individual w/o food for > 12 hrs & lying down with little movement in constant temp environment overnight

  • No moving, talking, or sleeping

• Difficult to measure

Resting Energy Expenditure (REE) or Resting Metabolic Rate (RMR)

resting in comfy position

• Approx. 10% higher than BMR/BEE

• Most accurate measuring → use indirect calorimetry

• Formula: REE (kcal/day) = 1.44 • (3.9 • VO₂ + 1.1 • VCO₂)

Considerations for Estimations of TEE & BMR

• Illness – severity

• Breathing – chemical or independently

• Age

• Unique hormonal profile

• Any gender interventions

• Weight

Energy Balance

cal consumed = cal expended, leading to maintenance of body weight

* Other factors can influence appetite & body weight

+Energy in / – Energy out

increased body energy stores

– Energy in / + Energy out

decreased energy stores

Total Energy Expenditure

• REE = 60-75%

• PAL = 20-25%

• TEF = 10%

Resting Energy Expenditure (REE)

1 kcal/kg per hour. 

• Energy necessary to sustain life

• Approximates BMR

• 30 mins in postabsorptive state

• factors affecting: body comp, sex, body temp, age

BMR

• 10-20% less than REE

• Lowest rate of energy exp. 

• Post-absorptive state

• Sleeping

• Thermal neutral environment

• Impractical to measure

Thermic Effect of Food (TEF)

 energy necessary to digest, absorb, metabolize, & store nutrients from foods consumed

factors effecting: amount of food & macro consumption

Physical Activity Level (PAL)

energy necessary to compete voluntary & involuntary body movements & behavior.

• Activity of daily living, exercise, sports, play

• Muscle contractions, maintaining posture, fidgeting

Estimated Energy Req (EER)

 avg dietary energy intake that is predicted to maintain energy balance in a healthy person of a defined age, gender, weight, height, & level of physical activity consistent w/ good health. 

Doubly Labeled Water

• Useful for measuring total daily energy expenditure

• Can’t be used for REE, TEF, PA

• Looks at H & O₂ in body

• Most common in metabolic research

Direct calorimetry

measures heat given off by the body through radiation, convection, evaporation

• Metabolic chambers – few research facilities

Indirect calorimetry

measures O consumption (VO₂) & CO₂ production (VCO₂)

• More common in metabolic research, critical care settings or sports performance

• Portable & nonportable

Respiratory quotient (RQ)

ratio CO₂ produced to O₂ consumed at cellular level.

• Only CHO oxidized = 1.0

• Only fat = 0.7

• Only protein = 0.8

• Mixed diet = 0.82 

Respiratory exchange ratio (RER)

 ratio CO₂ to O₂ exchanged at lungs. 

• Indirect calorimetry uses RER to approximate RQ