NS 1150: Prelim 01 Review

What is nutrition?

The sum total of processes involved in the intake and utilization of food substances by living organisms, including ingestion, digestion, absorption, transport, and metabolism of nutrients in food

What does environment influence?

Choice and decisions of food

True or False: Life without the nourishment of food is not possible

True

What is metabolism?

• It encompasses all chemical processes that occur within a living organism (a cell) to maintain life

• Glycolysis is at the center of metabolism

Why do we care about nutrition?

1. Food is medicine: food can help prevent disease

2. The type of food we eat influences health: development, management, and progression of chronic disease

What is a nutrient?

A substance found in foods that performs one or more physiological or biochemical functions in the body

True or false: All nutrients are the same

False: NOT all nutrients are the same

What are the major functions of nutrients?

1. Energy: all three macronutrients provide energy, but the body relies primarily on carbohydrates and fat

2. Structure: promote tissue growth and development, mostly proteins

3. Regulation: all nutrients

Note: the body makes changes and adapts to preserve protein

What are the classifications of nutrients?

1. Organic/Inorganic

2. Essential/Non-essential or Conditionally essential

3. Energy-yielding/Non-energy-yielding

4. Macronutrients/Micronutrients

What does organic and inorganic refer to? What are some examples?

• Organic: molecules with carbon atoms

  • Carbohydrates

  • Fats/lipids

  • Protein

  • Alcohol

  • Vitamins

• Inorganic: molecules without carbon atoms

  • Water

  • Minerals

Does certified organic and organic refer to the same thing?

No: certified organic means that there are no pesticides used while organic refers to molecules with carbon atoms

What are essential nutrients?

A substance that must be obtained from the diet, because the body needs it and cannot make it in the required amounts

Why do we need essential nutrients?

1. Energy production

2. Growth and development

3. Regulating body processes

4. Preventing diseases

What are nonessential nutrients? What are some examples?

• A substance found in the body and used by the body to promote health but not required to be consumed on the diet (we have the enzymes to make them)

  • Cholesterol

  • Carnitine

  • Creatine

  • Some amino acids

What are conditionally essential nutrients?

• Normally nonessential nutrient, but under certain circumstances (like growth or disease) it becomes essential

• Obtained from diet

  • Creatine and chronic kidney disease

What are macronutrients and micronutrients?

• Macronutrients: to preserve normal body functions, the human body needs these nutrients in large quantities

• Micronutrients: the human body needs these nutrients in smaller quantities

What are energy yielding nutrients?

Participate in pathways that make ATP

What are some energy yielding nutrients?

• Lipids/Fats: 9kcal/gram

• Carbohydrates: 4kcal/gram

• Proteins: 4kcal/gram

• Alcohol: 7kcal/gram

Note: Alcohol is not a nutrient

What type of nutrients are vitamins and minerals?

Essential, but not energy-yielding nutrients

How many liters of water do we need everyday? How can we obtain water? Why do we need water?

• About 2.4 L/day

• From liquid or solid/semisolid food intake, and oxidation of food

• We need water for:

  • Transport of nutrients, gases, and waste products

  • Medium for chemical reactions

  • Body temperature regulation

What are the two categories of non-nutrient components?

• Naturally occurring

• Added (intentionally or unintentionally)

What are three different non-nutrient components?

1. Phytochemicals: health-promoting compounds found in plants

   1. Compounds in tomatoes and garlic

   2. Antioxidants

2. Zoonutrients: health-promoting compounds found in animals

   1. Nonessential lipids in fish

3. Functional Foods: foods that are fortified or enhanced to promote health

   1. Phytochemicals, zoonutrients, probiotics

   2. Yogurt

Fill in the essential nutrients

What is dietary reference intakes (DRI)?

A set of dietary reference values to aid individuals in optimizing their health, preventing disease, and avoiding nutrient overconsumption

What are the categories for dietary reference intakes?

1. Estimated average requirement (EAR)

2. Recommended dietary allowance (RDA)

3. Adequate intake (AI)

4. Tolerable upper intake level (UL)

5. Estimated energy requirements and acceptable macronutrient distribution range

6. Chronic disease risk reduction intake

What is estimated average requirement (EAR)?

• The nutrient value estimated to meet the requirement of 50% of healthy individuals

• Average daily level of intake estimated based on scientific data to meet the requirements of 50% of healthy individuals. EAR is required to calculated RDA

What is recommended dietary allowance (RDA)?

Average daily level of intake sufficient to meet the nutrient requirements of nearly all (97–98%) healthy individuals; often used to plan nutritionally adequate diets for individuals

What is adequate intake (AI)?

• It is established when scientific evidence is not sufficient to determine an RDA. As an intake is not a requirement, is likely to exceed the actual requirements of almost all individuals in a life-stage group

• Intake at this level is assumed to ensure nutritional adequacy; established when evidence is insufficient to develop an RDA

What is tolerable upper intake/upper level (UL)?

• Used as the highest level of daily nutrient intake that poses no risks of adverse health effects to most individuals in the general population

• Maximum daily intake unlikely to cause adverse health effects. The UL is not intended to be a recommended level of intake, and there is no established benefit to healthy individuals if they consume a nutrient in amounts exceeding the recommended intake (the RDA or AI)

What is estimated energy requirements (EER)?

Used to estimate the calorie needs of the average person within a specific height, weight, gender, age, and physical activity pattern

What is chronic disease risk reduction intake (CDRR)?

Characterizes nutrient intakes that are expected to reduce the risk of developing chronic disease

What is the purpose of Dietary Guidelines for Americans?

• Every 5 years

• Purpose: inform policymakers, and nutrition and health professionals who develop food, nutrition, and health policy

What does the Dietary Guidelines for Americans explain, discuss, and consider?

• Explains data that supports key recommendations

• Discusses the health benefits of lifelong healthy dietary choices

• Considers nutrition and health across the lifespan

  • Infants and toddlers

  • Children and adolescents

  • Adults

  • Pregnancy and lactation

  • Older adults

What are dietary patterns? What is the central aim? What is it not? Is it the same for everyone?

• A dietary pattern refers to the combination of various foods, drinks, and nutrients that comprise an individual's total dietary intake over time, including the quantities, proportions, variety, and frequency with which they are consumed (The big picture of what you eat on a regular basis)

• The central aim to promote dietary patterns associated with positive health outcomes

• Dietary pattern is NOT about simply fulfilling daily recommended allowances

• Unique to each individual person across

A healthy dietary pattern limits added sugars to how much?

<10% of calories per day

How many calories do added sugars account for?

Added sugars account on average for almost 270 calories - or >13% of total calories - per day in the U.S. population

Intake of saturated fat should be limited to how much?

<10% of calories per day

What percent of individuals consume amounts of saturated fat consistent with the limit?

23%

What is the old and new advice for dietary cholesterol?

Old advice: Limit intake to <300mg per day

New advice: “individuals should eat as little dietary cholesterol as possible”

Healthy eating patterns limit the adult consumption of sodium to CDRR levels by how much?

≤ 2300 mg/day

What is the average intake of sodium for those ages 1 and older?

About 3393 mg per day

What is a nutritional scientist?

A person who conducts and/or evaluates nutrition-related research

What is a dietitian?

A nutritionist who helps people make healthy dietary choices

What are Dietary Guidelines?

They provide science-based advice on what to eat and drink to promote health, reduce risk of chronic disease, and meet nutrient needs

What aren’t Dietary Guidelines?

• Not lawful, no legal basis and not enforced

• Not mandatory, but forms the basis of Federal nutrient policy and programs

• Not clinical guidelines, not intended for treating diseases

What was common amongst British sailors in the 18^th century?

Scurvy

What are the symptoms of scurvy?

• Bruising blue/red spots on the skin

• Slow to heal wounds

• Bleeding from gums

• Loosening of teeth

• Muscle pain

• Joint pain

• Fatigue

• Fever, convulsions

• Death

How many sailors died from scurvy between the 16th and 18th centuries?

Responsible for more than 2 million deaths amongst sailors

How many men did Vasco de Gama and George Anson lose (mainly due to scurvy)?

• Vasco da Gama: lost 116 of 170 men on his first voyage to India in 1499

• George Anson: lost 1,666 of the 1,854 men following a 4-year circumnavigation trip in 1744

What can nutritional imbalance/inadequacy lead to? What are some modern examples?

• Can lead to major detrimental health impact on entire population

• Modern examples:

  • Obesity

  • Type 2 diabetes

What are some failed treatments for scurvy?

• Sulfuric acid

• Venesection (blood-letting)

• Drinking seawater

What are some effective treatments for scurvy?

• Eating rats

• “Scurvy grass” (Cochlearia officinalis)

• Citrus fruit

Who is James Lind? What is he known for?

• Surgeon’s mate in the Royal Navy in late 1730s

• Witnessed many cases of scurvy first-hand

• 1747: carried out the world’s first recorded “randomized controlled trail”

Regarding bio-medical research, fill in the blanks

Describe James Lind’s randomized controlled trial

• 12 sailors divided into 6 groups of 2 sailors

• Each group randomized to receive one of the following treatments:

  • A quart of cider daily

  • 25 drops of elixir of vitriol, three times a day

  • Half a pint of sea-water a day

  • Paste of garlic, mustard seed, horse-radish, balsam of Peru, and gum myrrh three times a day

  • Two spoonfuls of vinegar, three times a day

  • Two oranges and one lemon a day

Note: bolded example was the effective one

After James Lind’s randomized controlled trial, was scurvy cured?

No because of the challenges:

• Poorly documented study, published in 1753 (experiment done in 1747)

• Poor dissemination to Navy/wider public

• Lack of influence

• Unable to translate result into practical guideline/policy

• No one acted on these results

• No dietary guideline/policy implemented

Who was Gilbert Blane of Blanefield? What is he known for?

• Physician in the Royal Navy

• Reproduced James Lind’s study

• Used alcohol as a preservative to maintain lemon juice

• Blane recommended findings to Admiralty

• 1795: Royal Navy mandated lemon juice to be consumed daily by every sailor.

How much citrus was needed for the royal navy?

50,000 gallons of citrus juice per year

Regarding the 1800s, what are the benefits of a nutritional policy?

• Naval tactical superiority

• Protection and expansion of British Empire

• Economic productivity

What do food choices impact?

Development of society and economy

What does vitamin C act as for enzymes involved in collagen synthesis?

What enzymes use vitamin C to catalyze the addition of hydroxyl (OH) groups onto proline and lysine residues in the collagen peptide?

What does the addition of these hydroxyl groups allow?

What does a deficiency of vitamin C cause?

• Vitamin C (Ascorbic acid) acts as an essential co-factor for enzymes involved in collagen synthesis

• Prolyl-hydroxylase and lysyl-hydroxylase enzymes uses vitamin C to catalyze the addition of hydroxyl (OH) groups onto proline and lysine residues in the collagen peptide

• Addition of these hydroxyl groups allow the collagen peptide chain to crosslink into a triple-peptide helix structure, thus providing tensile strength
  • Deficiency of vitamin C results in ‘weak’ collagen resulting in breakdown to connective tissue in skin, muscle, joints, gum

  • This leads to the symptoms in scurvy.

What do humans and guinea pigs lack for vitamin C synthesis?

Although rats can synthesize their own vitamin C, what does cooking the meat destroy?

• Humans (and guinea pigs) lack a vital enzyme called GULO (L-Gulonolactone oxidase) required for vitamin C synthesis

• Other mammals including rats can synthesis their own vitamin C and therefore can survive on long voyages unaffected by scurvy

• In fact, eating rats provided a small amount of vitamin C which explains why this offered limited treatment against scurvy

• But cooking the meat will destroy its vitamin C content

Who is at risk of vitamin C deficiency?

• Intake deficiency:

  • Socio-economic: social isolation/nutrient insecurity

  • Behavioral: alcohol/Infant feeding practices

  • Pathology: allergy/eating disorders

• Malabsorption:

  • Inflammatory bowel disease

  • Bariatric surgery

• Increased consumption:

  • Smoking

• Increased excretion:

  • Kidney diseases

How can dietary guidelines help?

They can ask questions such as:

• How much vitamin C do we require every day?

• Is vitamin C requirement the same for everyone?

• How do we meet our vitamin C requirement from our diet?

• What happens if we over-supplement/are deficient in vitamin C?

• How do we educate/inform people about vitamin C?

• Do we need a National food fortification policy?

What does the Dietary Reference Intakes (DRI) include?

Documents issued by the Food and Nutrition Board:

1. Information on basic function of nutrients, food sources, and effects of deficiencies and excessive intakes

2. Offer quantitative estimates of nutrient intakes to maintain health in US and Canada

3. Addresses issues of safety, quality, and adequacy of the food supply

What are the life stage groups and years?

• Infancy: 0 – 6 months; 7 – 12 months

• Toddler: 1 – 3 years

• Early Childhood: 4 – 8 years

• Puberty/Adolescence: 9 – 13 years, 14 – 18 years

• Young Adulthood and Middle Ages: 19 – 30 years, 31 – 50 years

• Adulthood and Older Adults: 51 – 70 years, >70 years

• Pregnancy and Lactation

What are DRI reference values?

EAR, RDA, UL, AI

What do DRI reference values vary by?

Life stage group and sex

What does DRI help establish?

Dietary guidelines, national policies, and clinical guidelines

How do we meet our vitamin C requirement from our diet?

Recommendations on what to eat and drink to meet nutrient needs, promote health, and prevent disease

Who makes up the DGA advisory committee expert panel

Scientists, policymakers, healthcare providers, nutrition educators, and Federal nutritional program operators

What do DGAs use to assess benefits and risks associated with nutrient intake?

DRIs

What is the DGA framework?

What are nutrient dense foods?

• Nutrient dense foods contain higher macro/micronutrient per weight

• Lower saturated fat content, sugar and salt

• Nutrient dense food contain fewer calories

How can you avoid excess salt/sugar/fat?

Fill in the blanks

What are individualized dietary patterns?

• Choice of ingredients and preparation method

• Cultural background can have significant impact on food and beverage choice

• Must fit a range of budgetary constraints

• Variety within different food groups and incorporate fresh, frozen, dried, canned options

• Portion size important to meet calorie needs

• Lastly must align with individual/family preference

What is the national fortification policy?

• Fortification of food is the addition of nutrients that are not typically found in the food

• Fortification is a systematic approach to correct identified nutrient deficiencies in the population

• Not mandatory in the US, but recommended to food supplier/manufacturer

• Contrast with ‘enrichment’ which involves adding back nutrients that were lost during the processing of the food

What are advantages and disadvantages of the national fortification policy?

What happened in the 1920s regarding iodine fortification in salt?

• Iodine required by thyroid gland to produce thyroid hormone

• Deficiency in iodine triggers enlargement of thyroid (goitre) in attempt to make sufficient thyroid hormone, as well as hypothyroidism which can affect weight, fatigue, neuro-cognitive decline

• By 1924, iodine was fortified in table salt. Although not mandatory, this was widely adopted by industry, schools, and endorsed by medical communities

• Resulted in significant decline in the incidence of goitre and hypothyroidism

What happened in the 1930s regarding vitamin D fortification in milk?

• Vitamin D required for calcium absorption and bone calcification i.e. ‘hardening’ of bones

• Chronic deficiency of vitamin D lead to osteomalacia (rickets in children) due to decalcification of bones. Permanent disability if not corrected

• Vitamin D synthesized in skin but requires sun light exposure, which can be limited in Northern hemisphere

• Food and Drug Administration recommended (not mandated) vitamin D fortification in milk to reduce prevalence of vitamin D deficiency

What happened in the 1990s regarding folic acid?

• Folic acid is required for DNA replication, which is especially important in rapidly growing tissues such as the developing fetus

• Folic acid deficiency during pregnancy negatively impacts fetal development, such as spina bifida where the spine fails to form an enclosed tube leading to nerve damage

• The consequences can lead to lifelong disability, yet folic acid deficiency can be easily corrected with oral supplementation if detected early (or before) pregnancy

• In 1998, US government launched folic acid fortification in grain products e.g. bread, cereal, flour

• Fortification policy estimated to prevent 1300 babies each year from spina bifida and related defects

What do dietary guidelines for Americans provide a framework on?

A framework on promoting healthy dietary patterns to maintain health and reduce the risk of chronic disease

What do dietary patterns focus on?

Nutrient dense foods, avoid excess calories and limiting intake of salt, sugar and saturated fat

What do dietary patterns need to be?

Need to be individualized based on the culture, lifestyle, age, budget and other life factors

What do national fortification policies supplement?

Supplements additional nutrients to food

What do fortification policies prevent?

Can be very effective to prevent nutritional deficiencies and associated diseases in the population

Fill in the blanks

Why is nutrition assessment important?

• To identify nutritional status and nutrition-related diseases

• To determine appropriate nutrition therapy or programs

• To assess response to nutrition/medical therapy or programs

What are the types of nutrition assessments?

• Dietary

• Clinical

• Anthropometric

• Biochemical

In terms of dietary assessment, what does retrospective refer to?

• Looking back, remember foods consumed

  • 24-hour recall

  • Food frequency

In terms of dietary assessment, what does prospective refer to?

• Tracking intake, making a record of foods as they are consumed

  • Diet record

24 hour-dietary recall uses data from what?

• Food preparation methods

• Ingredients used in mixed dishes

• Brand name of commercial products

• Portion sizes

In a clinical and research setting, who interviews you during a 24 hour-dietary recall?

• Clinical: Interview by trained practitioner

• Research: Interview or self-administered recall (ASA24: Automated Self-Administered 24-Hour Dietary Assessment Tool)

• Takes 30-45 minutes to complete

What are the pro and cons of 24 hour-dietary recall?

• Pros

  • Intake can be quantified

  • Easy to complete

• Cons

  • Relies on recall (short-term memory)

  • May require multiple recalls to capture habitual intake

What is a Food Frequency Questionnaire (FFQ)?

• Assessing how frequently certain food and beverage items consumed over a specific extended period of time (typically 3 months to 1 year)

• Focus on consumption patterns and habitual intake

• Can be focused on specific food groups (i.e., vegetable intake) or all foods

What are pros and cons of Food Frequency Questionnaire (FFQ)?

• Pros

  • Capture habitual intake

  • Easy to collect

• Cons

  • Inaccuracies from incomplete listing of all possible foods

  • Relies on recall

What do dietary records record? Who analyzes them?

• Record all food, beverages, and supplements and amounts consumed over 3-7 consecutive days (weekdays and weekend days)

• Trained practitioner analyzes records to determine energy and nutrient intakes