Applications of nutrition in medicine:
1) Public health issues: Chronic diseases - heart disease, cancer, obesity, hypertension, stroke, diabetes; international nutrition issues (societies in transition with both over- and under- nutrition).
i. “Healthy Living is the Best Revenge” against chronic disease: 4 lifestyle factors —> 78% lower risk of developing a chronic disease cf those w/o any these healthy lifestyle factors
ii. Dietary practices divergent from recommendations are considered the 2nd leading cause of preventable death in the U.S., second to tobacco.
iii. At least 1 of 6 deaths in the U.S. is linked to poor diet & sedentary lifestyle, much greater than risk of dying from automobile accidents, homicides, infectious disease.
- Ambulatory medicine: Pregnancy; lactation & breastfeeding; healthy, growing children; obesity, hypertension; hyperlipidemia; Type 2 diabetes mellitus; elderly; chronic diseases (Type 1 DM), cystic fibrosis, chronic obstructive pulmonary disease; celiac disease; micronutrient deficiencies.
- Nutrition support/in-patients: ICU, surgical (esp. trauma, burns, transplant), short gut syndrome/feeding intolerance, premature infants; enteral (using the gut) or parenteral (by-passing gut: intravenous); specialized, immune-modulating formulas; micronutrient deficiencies
Gradual evolution of unified dietary recommendations:
Gradual evolution of unified dietary recommendations:
Dietary Guidelines for Americans, DASH Diet, & Mediterranean Diet, et al (Increased F/V & whole grains; Decreased SFA, TFA)
ASSESSMENT OF NUTRITIONAL STATUS AS PART OF MEDICAL H & P*:
4 Traditional components (none adequate alone; need combination of data, ie, just like all medical assessment);
- History: Intake (food/nutrient) relative to needs and risks + medical hx
- Anthropometrics: length/height, weight, (head circumference in infants), waist circumference, etc
- Exam: Clinical signs
- Labs: Biochemical changes/levels
- Most people aren’t going to see MD just for nutrition, and most MD’s don’t just do nutrition, so…
NUTRITION ASSESSMENT SHOULD BE PART OF ROUTINE MEDICAL EVALUATION
“History of Present Illness” (ie, who’s the patient & what’s the problem?):
Factors/conditions in HPI/”chief complaint” that place patients at risk for nutritional depletion or excesses:
• Impaired absorption
• Decreased utilization
• Increased losses
• Increased requirements (growth, high metabolic rate, work of breathing, etc)
• High/low level of physical activity
The high risk patient:
• Very young or very old
• Underweight or recent loss of > 10% of usual body weight, or both
• Obese w/ central adiposity/insulin resistance
• One consuming limited variety: inadequate or excessive intake of certain foods
• Protracted nutrient losses: malabsorption, enteric fistulae, draining abscesses or wounds, renal dialysis, chronic bleeding or rbc destruction, s/p bariatric surgery
• Hyper-metabolic states: sepsis, protracted fever, extensive trauma, burns
• Chronic use of alcohol or meds with anti-nutrient or catabolic properties: steroids, antimetabolites (e.g. methotrexate), immune-suppressants, antitumor agents
• Marginalized circumstances: Impoverishment, isolation, advanced age, altered mental status (incl mental retardation)
“Past Medical History” (where does nutrition/diet assessment fit in?)
a. Meds: include vitamins, mineral, or other nutritional supplements, energy drinks
b. Allergies: any food allergies (real or perceived) + drug allergies
c. Family Hx: diabetes, obesity, hypertension, coronary artery disease, osteoporosis
d. Social Hx: physical activity/exercise, diet (see below), habits (smoking, alcohol, drugs), socioeconomic status, who lives in the home;
e. Review of systems: Increased losses (vomiting, diarrhea); Decreased intake (nausea, anorexia); weight loss/gain (past 6 mo, past 2 wk); Increased requirement (fever, inflammation, growth, activity); rashes/bruising
Review of systems:
Important things to notice in Past medical History
Review of systems:
1) Increased losses (vomiting, diarrhea)
2) Decreased intake (nausea, anorexia)
3) weight loss/gain (past 6 mo, past 2 wk);
4) Increased requirement (fever, inflammation, growth, activity)
5) rashes/bruising
Dietary assessment: (amounts/sources)
- Qualitative: Screening questions/comments:
a) Most open-ended: “Tell me about your diet.”
i. (seeking info regarding variety, excesses, gaps)
b) More focused examples: ask about appetite (current/recent change), diet restrictions or special dietary practices, how many meals/snacks, frequency of eating out, variety, access to food, any recent changes, intake of sugar sweetened beverages, # of fruits/veg per day.
[The greater variety of sources of nutrients, the bigger the margin of safety; the more limited the diet, the higher the chance of deficiency or imbalance]
- Semi-Quantitative: Actual estimates of intakes of foods and/or nutrients
a) 24-hr recall/typical day: quick, fairly easy, esp. good for diets with limited variability; may not be representative of usual intake; better for assessment of food patterns (vs nutrients)
b) Diet record (including multiple days): better estimate of average food/nutrient intakes; time consuming, requires literacy, may change eating behavior; often acquired/interpreted w/ help of registered dietitian
Evaluation of Dietary Intake Data
FOOD guides (variety, types and sources of foods): compare to general public health diet guidelines:
a) My Plate - promotes healthy eating with a simple visual aid and offers tools and individualized approaches to estimated energy needs and activity levels (www.choosemyplate.gov); (see diet assignment)
b) 2015 Dietary Guidelines for Americans – 5 major themes:
1) healthy eating pattern
2) focus on variety, nutrient density, amounts
3) limited calories from added sugars & saturated fats, and reduce sodium intake
4) healthier food & beverage choices (fiber/whole grain, low/non-fat dairy, chips–> nuts; soft drinks–> water)
5) be active.
Evaluation of Dietary Intake
NUTRIENT standards
a. Dietary Reference Intakes (DRI’s): from Food and Nutrition Board, National Academy of Sciences; present a shift in emphasis from preventing deficiency to decreasing the risk of chronic disease through nutrition.
1) Estimated Average Requirement (EAR): intake estimated to meet requirement defined by a specified indicator of adequacy in 50% of the individuals in a life stage and gender group; includes an adjustment for assumed bioavailability of the nutrient; used to assess inadequate intakes and planning goal intake for mean intake of a group.
2) Recommended Dietary Allowance: average daily dietary intake level sufficient to meet the nutrient requirements of nearly all (95-97%) individuals in a life stage and gender group; RDA applies to individuals, not to groups; EAR is foundation of setting RDA; should be used as a goal for dietary intake by healthy individuals, not to assess/plan diets of groups
b. Sources of data for establishing nutrient requirement and allowance:
- Nutrient intake data/Epidemiological observations
- Biochemical measurements relative to intake
- Experimental depletion-repletion studies
- Effects of intervention trials, dose response to supplements;
c. DRI’s provide the nutrient basis for all federal Nutrition programs & to set the daily values (DV) used by Food & Drug Administration’s mandated nutrition labeling
Anthropometrics (too big/too small ?)
- Reflect growth and development or an increase/decrease in body fat and muscle tissue
- Measurements are relatively easy to perform and equipment is fairly inexpensive
- Information non-specific but quite sensitive (small changes detectable, but can be multiple causes)
- Major limitation is inaccuracy of measurement, recording
- Height , weight (+- head circumference) compared to standards based on age, sex:
Pediatrics: WHO/ CDC growth charts (0-24 mo); NCHS/CDC w/ BMI: 2-20 yr, 2000
Adults: Body Mass Index (BMI) weight in kg divided by height in m2
BMI Interpretation: Underweight < 19 Acceptable weight 19-26 Overweight 26.1-29 Obesity 30-40 Morbid Obesity > 40
Clinical/physical exam [If you don’t look for it, you won’t see it!!]
- Particular attention to skin (rash, petechiae, bruising, pallor), hair (pluckability, color changes, texture), mouth (sores, cracked lips, tongue), eyes
- Loss/gain of subcutaneous fat
- Muscle wasting
- Edema - extremities, sacral
- Neurologic exam (reflexes, vibratory sense, balance, gait/ataxia, Romberg, mental status )
Biochemical/laboratory
- [Ideally] measurements reflect ‘status’ and body stores of individual nutrients
- Measurements specific but not sensitive (e.g. abnormality in single nutrient can be measured (specific) but no detectable change in blood/urine level until deficiency quite marked (not sensitive)
- Commonly used tests:
a) albumin - reflects protein synthesis, but levels decreased w/ stress/inflammation
b) prealbumin - shorter half-life compared to albumin; reflects more acute status but also decreased ‘s w/ stress
c) transferrin - iron and protein status
d) complete blood count and total lymphocyte count
e) Specific nutrient levels (e.g. retinol, 25-OH-Vit D, ferritin, etc)
Health Behavior Change (brief principles)
a. Traditional dietary counseling focuses on what patients should be advised to eat;
b. Concept of why they eat as they do & impediments to changing dietary behavior less understood & less emphasized
c. Failure to change diet in most patients is not the result of inadequate motivation, but of excessive difficulty/barriers.
To achieve change:
1) reduce the difficulty and/or
2) increase the motivation.
[ie, barriers to change typically»_space; factors contributing to motivation for change
Health Behavior Change
“Readiness to change” is related to 2 key concepts:
a. “Readiness to change” is related to 2 key concepts: importance (Is change worthwhile?) & confidence (Whether pt believes he/she can achieve the change). Examples:
b. A person who is overweight may want to change & believes it is important, but may not have confidence to do so (e.g. may have failed in past), or many factors may get in the way of making change.
i. An alcoholic or smoker may feel confident that they could quit anytime, but may not believe it is important to do so.
c. All patients should receive at least some counseling to modify diet to promote health +- to achieve specific therapeutic goals.
d. Starting point is to ask patient to describe their diet and level of physical activity; ask patient if/where they see potential for change, & how they would like to begin (collaborative goal setting).
WHY Nutrition?
a. Dietary practices “divergent” from recommendations considered to be 2nd leading cause of preventable death in U.S.
b. Unhealthy eating & inactivity contribute to 310,000-580,000 deaths/yr…
i. 13x > guns
ii. 20x > drug use
c. Return on investment from community based initiatives that promote physical activity & nutrition & discourage smoking was ~$5.60 in health care cost savings for every $1 spent
Nutrition Support – Hospital Settings
24 % of patients in pediatric hospitals are malnourished
Undernutrition in Hospitalized & Elderly Populations
a. 33-54% pts in large surgical & medical hospital wards malnourished
b. 23-85% pts in long term care settings
c. 5-10% older adults living in the community
Nutrition & Medicine
a. Physicians consistently indicate belief that nutrition is important, but…
b. Report less confidence & satisfaction related to dietary counseling
c. Survey:
Smoking discussed w/ 77% of pts
Diet discussed w/ only 50% of pts
Pts who were asked about diet significantly more likely to have lost weight, tried to lose wt, increased physical activity, improved diet
Nutrition Assessment
a. Should be part of routine medical assessment
b. Based on data from… History Anthropometry/measurements Physical Exam Labs
Nutrition Assessment – WHEN?
a. Who’s at high risk:
i. Very young
ii. Very old
iii. Underweight/overweight
iv. “Hypermetabolic”
v. Alcoholic
vi. Impoverished/marginalized/altered mental capacity
b. Chronic conditions
Dietary Assessment in the Medical History – “HPI”
a. Conditions with Increased risk for nutritional problem:
i. decreased absorption – cystic fibrosis, celiac disease
ii. increased losses – blood loss, diarrhea
iii. increased requirements -growth, pregnancy, lactation, pulmonary/cardiac disease
iv. Limited intake – variety, amount
b. Consider nutrient/energy inadequacies or excesses
Nutrition Assessment in the Medical History
a. Meds/supplements – herbals, mega-vits, etc
b. Allergies – drugs & food
c. Family Hx – (diet related chronic illnesses?)
d. Soc Hx: Diet, physical activity, habits, SES
i. Critical to ask about diet, physical activity, and habits
e. Review of Systems:
i. Wt loss/gain, increased losses, decreased intake, systemic illness (↑ requirements/↓ intake)
Dietary Assessment: Qualitative
a. Screening questions…
“Tell me about your diet…”
“Tell me what you ate yesterday…”
“Where do you eat most of your meals?”
b. Listening for:
Variety (vs restriction)
Excess/inadequacy
Issues relevant to the patient: saturated fat, calories, Na,++Ca,++ Fe
Qualitative Dietary Assessment by FOODS
a. Variety
b. Excess
i. Calories
ii. Saturated fat, trans
iii. Added sugars
iv. Salt
c. F/V, Whole grains, Dairy
d. Habits
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Protein Biochem and Metabolism56
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Protein Biochemistry56
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Purine and Pyrimidine Metabolism42
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Inborn Errors: Amino Acid and Urea Cycle41
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Inborn Errors: Glycolipid Disorders37
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Hospital Based Nutrition49
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Nutrition Intro41
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Dietary Guidelines41
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Eating Disorders19
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Fat Soluble Vitamins43
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Water Soluble Vitamins41
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Micronutrients: Trace Elements56
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Malnutrition23
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International Nutrition42
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Adult Obesity and Metabolic Syndrome60
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Obesity Treatment: Diet and Activity70
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Regulation of Energy Intake & Body Weight Regulation38
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Pediatric Obesity: Health Implications36
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Obesity Treatment: Drugs, Surgical Options and Popular Diets36
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Nutritional Counseling for Behavior Change20
