Chapter 2: Nutrition Tools – Standards and Guidelines

Methods for Food Intake Analysis

• 3 classical self-report techniques for estimating habitual food and nutrient intakes.

  • 24-h Diet Recall

  • Client remembers everything eaten & drunk in the past 24 h.

  • Advantages

    • Minimal effort for the client; can be completed in ≈20 min.

    • Low cost; suitable for large surveys.

  • Disadvantages

    • Relies entirely on memory → omissions, telescoping, mis-reporting.

    • The recorded day may be atypical (week-end, celebration, etc.).

    • Social desirability bias: client may alter answers to please interviewer.

  • Diet Record / Food Diary (3–5 days; sometimes 7 days)

  • Client weighs or measures foods as consumed and writes them down in real time.

  • Advantages

    • Does not depend on memory.

    • Can capture details on brand names, preparation method, time, mood.

  • Disadvantages

    • High respondent burden (time, accuracy, weighing scales required).

    • Re-activity: eating pattern may change because of the act of recording.

  • Food-Frequency Questionnaire (FFQ)

  • Structured list of foods; respondent indicates habitual frequency & sometimes usual portion.

  • Advantages

    • Quick, inexpensive; often self-administered or online.

    • Can be nutrient-targeted (e.g., calcium FFQ, carotenoid FFQ).

  • Disadvantages

    • Limited food list may omit culturally specific foods.

    • Frequency categories can be confusing ("3–5× wk"?).

    • Intrinsic day-to-day variation not captured.

Dietary Guidelines & Nutrition Objectives

• Purpose: steer the general population toward eating patterns that maintain health & prevent disease.

• National differences exist; this course focuses on Canadian standards.

• Principal Canadian reference documents

  • Tables 1-8: Nutrition Recommendations in Eating Well with Canada’s Food Guide.

  • Tables 2-2 & 2-3: Healthy Food Choice resources.

  • Appendix A, Table A-1: Canadian Nutrition Recommendations.

Interpretation of Food Intake Data

• Compare a client’s average daily intake with at least two of the following:

  • Eating Well with Canada’s Food Guide (Figure 2-4).

  • Canadian Nutrition Recommendations (Appendix A, Table A-1).

  • DRIs (inside front cover of textbook).

• Always contextualise with seasonal availability, price, convenience, cultural/religious restrictions, regional foods, etc.

Dietary Reference Intakes (DRIs)

Overview

• Jointly developed by Canada & the U.S. to replace/expand the 1989 Recommended Nutrient Intakes (RNI).

• Provide quantitative reference values for:

  • Vitamins, Minerals, Carbohydrates, Lipids, Protein, Fibre, Water, Energy.

• Multifunctional Goals

  • Establish intake goals for individuals.

  • Assess population adequacy & plan institutional menus.

  • Inform policy (e.g., mandatory fortification with iodine in table salt, vitamin C in evaporated milk).

  • Set safety limits & chronic disease prevention benchmarks.

Key DRI Terms

• RDA (Recommended Dietary Allowance) – intake goal meeting the needs of 97.5\% of a defined group.

• EAR (Estimated Average Requirement) – median requirement for a life-stage / sex group; basis for calculating RDA.

• AI (Adequate Intake) – observed/approximate intake presumed adequate when evidence is insufficient for an RDA.

• UL (Tolerable Upper Intake Level) – highest daily intake unlikely to pose adverse effects.

• AMDR (Acceptable Macronutrient Distribution Range) – proportion of total kcal from each energy-yielding macronutrient associated with reduced chronic-disease risk while providing adequate nutrients.

AMDR for Adults

• Carbohydrate: 45\%\;–\;65\% of total kcal.

• Fat: 20\%\;–\;35\% of total kcal.

• Protein: 10\%\;–\;35\% of total kcal.

Design Principles

• Aim at health maintenance & chronic-disease prevention for healthy individuals.

• Represent optimal (not minimal) daily intakes averaged over time (not single-day targets).

• Factors considered: BMI reference wt/ht, age, multi-day average.

• Factors not considered: physical activity (elite athlete), specific dietary patterns (vegan), latitude (vitamin D synthesis), lifestyle (smoking ↗ vitamin C need), disease states.

Proper Use & Misuse

• For most nutrients (except energy) RDA ≈ \text{mean}+2\,\text{SD} → covers 97.5\% of population.

• Energy recommendations are set at the mean (50th percentile) to prevent obesity.

• Intake < RDA ≠ deficiency; implies increased risk only.

  • Persistent intake < \tfrac{2}{3} of recommendations (3-day average) signals high risk.

Canada’s Food Guide (CFG)

• Practical translation of DRI into food portions.

• Evolution

  • 1992 update → "4 food group" focus.

  • 2007 update → maintained 4 groups, more emphasis on variety, daily servings.

  • 2019 revision → plate model emphasising proportions: ~½ plate vegetables & fruits (plant-based), ¼ whole-grains, ¼ protein foods; water as drink of choice.

• Obtainable at Health Canada website → Food & Nutrition → Eating Well with Canada’s Food Guide.

Foods to Limit (discretionary/"other" foods)

• High Cal, fat, sugar, Na:

  • Desserts (cakes, pastries, cookies, ice cream, etc.).

  • Fried/salty snacks (French fries, chips, nachos).

  • Sugary beverages & alcoholic drinks.

Canadian Nutrition Recommendations (Table A-1)

• Adequate energy for healthy body weight.

• Meet essential nutrient DRIs.

• Reduce sodium; follow Low-Risk Alcohol Drinking Guidelines.

• Caffeine ≤ 4 regular cups coffee (~400 mg caffeine).

• Fluoride in drinking water: 0.7\,\text{mg L}^{-1}.

Nutrition Labelling (post-Dec 2007; revised 2022)

Objectives

• Standardise on-pack information & regulate claims.

• Enable informed consumer choice.

Scope

• Mandatory on almost all pre-packaged foods.

• Exemptions (no Nutrition Facts box):

  • Fresh produce; raw meat/poultry/fish; in-store prepared foods (bakery, deli salads); items with few nutrients (coffee beans, tea, spices); alcoholic beverages.

Nutrition Facts Box

• Must display for a specified serving size:

  • Energy (Calories).

  • 12 core nutrients (fat, sat fat, trans fat, Na, carbs, fibre, sugars, protein, cholesterol, potassium, Ca, Fe).

  • % Daily Value (%DV) for most nutrients.

Serving Size

• Stated beneath "Nutrition Facts"; all data refer to this quantity.

• Uses household measures (cup, slice) & metric (g, mL).

% Daily Value

• A benchmarking tool:

  • < 5\%\,\text{DV} → "a little" of that nutrient.

  • > 15\%\,\text{DV} → "a lot" of that nutrient.

• Facilitates product comparison independent of portion size.

Ingredient List

• Mandatory, descending order by weight.

• Key for allergy checks & nutrient inference (e.g., sugar synonyms).

Nutrient Content Claims (Table 2-5)

• Regulated phrases allowed only when strict criteria met (e.g., "low fat", "high fibre").

• Optional; usually front-of-pack for marketing.

Diet-Related Health Claims (Table 2-6)

• Only 5 authorised pairings of diet & disease risk reduction in Canada:

  1. Low Na & high K diet ↓ risk of hypertension.

  2. Adequate Ca & vitamin D ↓ risk of osteoporosis.

  3. Low sat/trans fat diet ↓ risk of heart disease.

  4. Diet rich in vegetables & fruits ↓ risk of some cancers.

  5. Chewing gum/hard candy with minimal fermentable carbs ↓ risk of dental caries.

Front-of-Package (FOP) Nutrition Symbol (2022 revision)

• "High in" symbol flags foods exceeding thresholds for saturated fat, sodium, or sugars.

• Aims to prompt quick at-a-glance healthier choices.

Controversy 2: Phytochemicals & Functional Foods

Phytochemicals

• Bioactive, non-nutrient compounds from plants (phyto = plant).

• May confer health benefits beyond essential nutrients (antioxidant, hormone-like, anti-inflammatory).

Food Sources & Observed Benefits (Table C2-2)

• Flavonoids (berries, tea, wine, chocolate) → potential cancer/cardiovascular protection.

• Isoflavones/Genistein (soy) → possible bone health, but high doses ↑ tumour growth in lab animals.

• Lignans (flaxseed) → hormone modulation.

• Lycopene (tomatoes) → prostate cancer risk reduction.

• Organosulfur compounds (garlic, onions) → antimicrobial, heart-health.

Supplements vs. Whole Foods

• Isolated phytochemical pills can exert powerful, partly unknown effects.

• Limited human safety data; example: concentrated genistein promoted cancer progression in rodents.

• Consensus: Food matrix is safest & most effective → diversify vegetables, fruit, whole grains, legumes (Table C2-4 tips).

Functional Foods

• Conventional-looking foods that, by nature or design, deliver physiological benefit / ↓ disease risk beyond basic nutrients.

• Blur boundary between "food" & "drug" (Table C2-3).

Naturally Occurring Examples

• Broccoli sprouts → sulphoraphane; studied for cancer prevention.

• Dairy fat (butter, cheese) containing CLA (conjugated linoleic acid) → explored for body composition, immunity.

• Cranberry juice phytochemicals → reduced urinary-tract infections.

• Yogurt with live Lactobacillus (probiotic) → modulates gut microbiota; may reduce lactose intolerance, diarrhoea.

Added/Engineered Examples

• Cholesterol-lowering margarine with added phytosterols/stanols → competitively inhibit intestinal cholesterol absorption, lowering LDL-C.

• Raises regulatory & ethical questions: when does fortification turn food into medication? Who oversees claims? Long-term safety?

Ethical, Philosophical & Practical Considerations

• Memory-based dietary assessment conflates precision with accuracy; complementary biomarkers & tech (apps, images) are emerging.

• DRIs target healthy populations; using them for clinical patients requires professional judgement.

• Over-reliance on front-of-pack symbols may simplify complex nutrition (nutrient vs. food-based thinking).

• Functional foods & nutraceuticals illustrate the tension between public health nutrition (whole-diet approach) and commercial interest in single "magic bullet" ingredients.

These bullet-point notes capture every concept, definition, example, numeric reference, and the broader context needed for a thorough understanding of Chapter 2: Nutrition Tools — Standards & Guidelines.