Nutrition Midterm

What is Nutrition

The science that studies food and how it nourishes us and influences our health. The study of food, including: consumption, digestion, absorption, storage, safety, recommended amounts, factors that influence eating patterns, global food supply

What is food?

**Food:** the plants and animals (and other ‘food-like’ substances) that we eat. Provides what humans need to sustain life and support growth and health.

What is nutrition?

**Nutrition:** the science that studies food and how it nourishes us and influences our health

How is nutrition/diet linked to chronic disease prevention?

The fact that several of the leading causes of death in the US have diet-linked risk factors; improving dietary patterns could have a large impact at population-level on things like chronic disease (heart disease, diabetes, stroke), weight status, adequate nutrient intake, environmental, food security and sustainability health certain types of cancers.  

6 groups of essential nutrients

**Macronutrients:** carbohydrates, fats (and oils), proteins, and water. **Micronutrients:** minerals and vitamins

What are 3 macronutrients and kcal/gram for each

**Carbohydrate:** provide 4 kcal of energy/gram. **Fats:** provide 9 kcal of energy per gram. **Proteins:** provide 4 kcal of energy per gram

What are the 2 groups of micronutrients?

Mineral and vitamins; needed in relatively small amounts to support normal health and body functions

How is energy in food measured?

kilocalories. Atwater system: caloric value estimated by adding up calories provided by the energy-containing nutrients (carb, fat, protein, alcohol)

What are the DRIs

**Dietary Reference Intake**  

It’s the amount of nutrition needed to prevent deficiency in healthy people. And amount of a nutrition that may reduce the risk of chronic diseases

Define EAR

**Estimated Average Requirement (EAR):** the average daily intake level of a nutrient that will meet the needs of half of the health people in a particular life stage and gender group, used to determine RDA of a nutrient

Define RDA

**Recommended Dietary Allowance (RDA):** the average daily intake level required to meet the needs of 97-98% of health people in a particular life stage and gender group

Define AI

**Adequate Intake (AI):** recommended average daily intake level for a nutrient that is assumed to be adequate. Based on observations and estimates from experiments

Define UL

**Tolerable Upper Intake Level (UL):** highest average daily intake level that is not likely to have adverse effects on the health of most people. Consumption of a nutrient at levels about the UL is not considered safe

EER vs AMDR

**Estimated Energy Requirement (EER):** average dietary energy intake to maintain energy balance; based on age, gender, weight, height, and level of physical activity

**Acceptable Macronutrient Distribution Range (AMDR):** the range of energy intake from carbohydrate, fat, and protein associated with reduced risk of chronic disease

Sources of ‘trustworthy’ nutrition advice

education credentials, government agencies, CDC, national institute of health (NIH), professional organization publish nutrition research and information, science based consumer advocacy groups.

Types of research studies

animal studies, clinical trials, epidemiological st

udies

Discuss the various influences on eating and appetite (social, cultural, sensory, learned) and examples of each

o   Sensory: looks, smell, temperature, texture

o   Social/cultural: family, food rules, meal times, eating out vs eating at home

o   Learned: food rules: eating desert after dinner, 3 meals a day, clean your plate

Characteristics of a healthy diet

Adequate, Moderate, Nutrient dense, Balanced, Varied  

Hunger v Appetite

Hunger: physiological/biological urge or need for food

Appetite: desire influenced by many factors, not always hunger

What is nutrient density

The ratio of the amount of beneficial nutrition relevant to food energy content per amount consumed

**Tools for creating a healthy diet in the US (food labels, 2010 DGA’s, My Plate, other eating plans)**

DGA – Dietary guidelines for Americans 

3 stage process: Review science, Based on advisory report, prior versions of DGA’s, Considerations of public and federal agency comments. Implementation

Components of a food label

statement of identity, new contents, ingredients (descending by weight), nutrition fact panel, allergy info

How to use knowledge of the macronutrients to calculate values on a nutrition facts panel (% DV, calories from fat, carb, protein, etc.)

Fat: 4.5 grams X 9 kcal/grams = 40.5 kcal (\~40) 

Carbo: 10 grams X 4 kcal/g = 40 kcal  

Prot: 5 grams X 4 kcal/g = 20 kcal 

%DV: 100.5 kcal 

Nutrient claims on food labels  - how is it determined what manufacturers are allowed to say about a certain food on the label

The new label shown was altered to help consumers is a liable to their greatest benefit. 

Nutrient Labeling and Education Act (NLEA) 1990- the goal is to bring a sense of order of understanding terms used in describing food products. Mandatory format and content of food labels. Evaluate scientific basis for health claims. Set comprehensive standards for nutrition claims. Ex. “Light” 

The food product must contain the FDA designed amount of nutrition per reference amount (or stander serving size). Ex. “Low cholesterol”

What are the Dietary Guidelines for Americans (DGAs)

Set of principles developed by USDA & DHHS 

It’s designed to promote health, reduce risk of chronic disease, reduce the prevalence of obesity.

Why do we need DGAs?

Basis of federal nutrition policy, education, outreach, and food assistance programs. They influence the DG other countries will have. I’ll federal dietary guidelines for the public are required to be consistent with the DG; School policy + school lunch program, SNAP, WIC. 

What make the current DGAs different from some past guidelines?

They began giving recommendations by life stages

How often are DGAs updated?

every 5 years

What is my plate?

Comprehensive nutrition communication initiative. The official food icon of a DGA’s. Meant to serve a sample guide to help consumers choose healthful foods. Provides a visual reminder to help consumers make nutritious food choices in form healthy eating habits

What are carbohydrates?

They or one of the three macro nutrients. An important energy source. Consist of carbon, hydrigen, and oxygen atoms

Why do we need carbohydrates?

for energy, helps preserve protein for other uses

Why are carbohydrates an important source of energy

brain

Carbohydrate Categories (simple v complex)

Simple – broken down quickly by the body to be used as energy. Monosaccharides = glucose, fructose, galactose. Disaccharides = Maltose, lactose, sucrose 

Complex – animal store glucose as glycogen. Stored in body is in the liver and muscles. It’s not found in foods which makes it not a dietary source of carbohydrates. Polysaccharides = starches, fibers, glycogen.

What is glucose?

The most abundant sugar molecule on a diet and bodies. Attached to are other sugars in foods to form disaccharides or other complex carbs

What is glycogen?

polysaccharide, also forms glucose

What is fiber?

The non-digestible part of plants

How is fiber linked to satiety?

Physiologic sensation of fullness

Why is fiber important? (health benefits)

lower cholesterol, regulating good gut bacteria, controls weight, lowers the risk of type two diabetes, lowers cancer risk, reduces inflammation

Fiber intake levels among Americans

90% of women don’t meet the recommended intake of fiber 

97% of men don’t meet the recommended intake for fiber 

Only 5% get the fiber intake they need 

Adequate Intake of fiber is 14 grams  

Good food sources of dietary fiber

legumes, whole grain, fruits and veggies

What is the glycemic index

measure of a food’s ability to raise blood glucose level

Enriched vs Fortified Foods

Enriched foods: those which lost nutrients during processing and are added back

Fortified foods: extra nutrients added by manufactured, but not necessarily to replace those lost during processing

Main sources of added sugar in US diet

sugar-sweetened beverages (SSBs), peanut butter, flavored rice mixed, salad dressings

What are some health effects of excess added sugar consumption?

weight status, type 2 diabetes, cardiovascular health, chronic inflammation

What are the DGA recommendations about added sugars

less than 10% of their total daily calories as part of a healthy diet

Insulin and Glucagon

Insulin facilitates the uptake of glucose by body cells. Glucagon causes breakdown of liver stones of glycogen onto glucose

What are Fats

one form of a large group of organic substances called lipids

Why do we need fats

For energy. Much of the energy doing the rest comes from fat. Fat is used for energy during exercise especially after glycogen is depleted. Fat is also used for energy storage. They are essential for our body function

Difference between fats and oils

Fats (like butter) are solid at room temperature. Oils (like olive oils) are liquid at room temperature

How does the shape of a fatty acid impact cardiovascular health

Fatty acid chains or length determine how the fat is digested, absorbed, and transported in the body.

Short (<6 carbons), Medium (6-12 carbons), Long (>13 carbons)

Types of fatty acids (saturated vs unsaturated)

Saturated: has a single bond

Unsaturated: has a double bond

What is cholesterol

It’s a sterol. It’s part of every cell membrane in the body. Used to synthesize hormones like estrogen, adrenal hormones, bile, vitamin D. types of cholesterol in the blood stream is most important in terms of health risk

Dietary sources of cholesterol

animal products

Food sources of fat

certain animal products, oils, butter, full fat dairy, nuts, seeds and avocados

What is trans-fat

Hydrogen Adams that arranged in different positions 

Cis – Same side of carbon chain  

Trans – opposite side of carbon chain 

Why is trans-fat harmful to health

increased risk of CVD

How was trans-fat eliminated from our food supply

by legally imposed limits on the amount that can be contained in packaged food. Some governments have implemented nationwide bans on partially hydrogenated oils, the main source of industrially-produced trans fats.

What are essentiall fatty acids

omega 6 and omega 3

Strategies to recognize or reduce fat in our diets

using food labels, eating lots of fruit/veggies/whole grains, choosing oils over solid fats like butter, lower fat dairy and meats

What is CVD

Cardiovascular disease. Group of disorders of the heart and blood vessels. Most common form: CHD, stroke, hypertension, peripheral vascular disease, heart failure  

What are modifiable risk of CVD

diet and physical activity

What is the DGAs recommendation for saturated fat

to consume less than 10% of calories per day from saturated fat

Link between saturated fat and heart disease

Decreased removal of LDLs from blood. Contributes to the formulation of plaques that block arteries. Increase triglyceride levels.

What are proteins

Macronutrients. Large molecules and cells of all living things. Only one that contains a special form of nitrogen that the body can readily use. Contain in an amine group

Why do we need proteins

Cell growth, repair, maintenance. Enzymes and hormones. Fluid and electrolyte balance. Immune system – antibodies are proteins, blood clotting.  

What are amino acids and how are they used in our bodies 

Building blocks of proteins. Involved in almost everybody function, including growth and development, healing and repair, normal digestion, and providing energy for the body. 

What are essential amino acids (definition) 

Body needs to get through diet. There are 9 essential amino acids and 11 nonessential amino acids. 

Complete vs. incomplete protein 

Incomplete Protein – does not contain all of the essential amino acids  

Complete Protein – contains all of the essential amino acids  

Protein status of the average American diet 

0\.8 g of protein/KG of body weight is the estimate for average Americans 

Complementary proteins 

Two or more foods that when combined have all nine essential amino acids. They don’t all have to be consumed at the same meal 

Food sources of dietary protein 

Eggs, almonds, chicken breast, oats, cottage cheese, Greek yogurt  

Protein Deficiency (marasmus, kwashiorkor) 

Usually occurs when people are not getting adequate calories. 

Marasmus  

Extreme tissue wasting stunted growth and development 

Due to grossly in adequate intakes of energy, protein 

Most common in young children 6 to 18 months living impoverished conditions  

Can lead to death if untreated  

Kwashiorkor  

Typically seen in young children 1 to 3 years old who are weaned early and feta low protein starchy cereal. Can develop quickly. Leads to edema in belly 

**Why do we need water?**  

How much water should we drink? 

The amount of water varies by individual. But it depends on where you live (hot vs cold climate), your activity levels, other health issues. Adequate intake for adult males: 3.7 L of total water per day Adequate intake for adult woman: 2.7 L of total water per day. This does include water from food, plants, drinking water, and other beverages 

Environmental impact of bottled/designer water consumption in the US  

Plastic water bottles we buy end up in landfills  

Estimated that 3 L of water is used to package 1 L of bottled water 

Depending where you live the water might not be good to drink  

Why are Dietary Assessment Methods Important

For nutrition research depends on being able to assess what and how much people eat. It’s used to estimate intake of energy, nutrients, food groups, and dietary patterns  

24 Recall (Dietary Assessment Method)

The person remembers/recalls food and drinks consumed during the pervious 24 hours. Conducted during an interview; in person, over the phone, or computer assisted. Food models, household measuring spoons/cups, photographs used to enhance portion size. 

In-depth interview with open-ended format. Interviewers need to help the person remember without leading the respondent. 

Food Record (Dietary Assessment Method)

FFQ (Dietary Assessment Method)

Used in epidemiological studies of chronic disease. It estimates how frequently certain foods and beverages are consumed during a specific period (usually the past year). It’s less detailed information but a wider time period. General questions about whether a specific food is eaten at a certain frequency. They include an estimation of portion sizes. 

Fill Out process: listing all foods and drinks consumed by one person on one or more days. The intake is recorded by the subject at the time the food/drink are being consumed. There are instructions given how to measure the portion size to keep accurate records. Multiple days required to represent typical and take it should include a weekend and week day. Record checked after submission by dietician 

New Tech(Dietary Assessment Method)