Disease Risk Factors
Exercise
Body Mass
Drug Use
Balanced Diet (fruits/veggies, lean protein, whole grains)
Genetics
Environment
Nutrition
How compounds in foods nourish and affect body functions/health. The levels and functions of nutrients/other compounds in food and the body. How to build nutritious diets
Nutrients
Chemical needed by an organism to live and components within food (not made by body), categorized into 6 classes:
water
carbohydrates: glucose
protein: amino acids
fat: fatty acids
vitamins
minerals
Diet
A pattern of food choices.
Malnutrition
State of health that occurs when body is improperly nourished (under or over-nourishment).
Healthy Diets
Consist of a variety of foods balanced by a moderate intake of each 6 essential nutrients, fiber, and phytochemicals. Aim to prevent malnutrition and prevent nutritional deficiency diseases/chronic diseases.
Functions of Nutrients
Act as building blocks, provide energy, serve as enzymes or “helpers”.
Calorie
Measurements of energy (kcal).
Energy
Contained within chemical bonds in food structures and is released when these bonds are broken by the body to form ATP.
Enzymes
Molecules that accelerate or catalyze a chemical reaction. Many involved in breaking down the foods we eat to release nutrients. Most end in “ase”.
Substrates
The molecules enzymes act on.
Active Site
Location that the substrate physically binds to.
Organic Compound
Compound containing carbon.
Macronutrients
More needed, energy-yielding nutrients:
Carbohydrates (4kcal per g)
Fat (9kcal per g)
Protein (4kcal per g)
Water (0 kcal per g)
Micronutrients
Less needed, non-energy-yielding nutrients:
Vitamins (0kcal per g)
Minerals (0kcal per g)
Functions of Water
Fluid medium in/outside of cells, lubricant, cushion, helps chemical reactions, transports, removes waste.
Phytochemicals
Non-nutrient compounds of vegetal origin that determine color, taste, or other characteristics. Main sources are fruits, vegetables, and whole grains.
Bioactive Foods
Non-essential molecules present in foods that can modulate one or more metabolic processes, promoting health.
Fibers
Non-nutrient, indigestible portion of plant foods, contribute to health.
Balance
Meeting nutritional needs from each food group.
Moderation
Not consuming extreme amounts of a substance.
Variety
Eating different types of foods within each food group.
Energy Requirement
Amount of energy and each nutrient the body needs to maintain a defined level of heath, varies by person.
Recommendations
General calculation of requirements, often food-based, that considers how we absorb nutrients from foods that are available.
Dietary Reference Intakes (DRI)
Intake standards set for nutrients.
Recommended Dietary Allowance (RDA)
Provides optimal function and meets the need of almost the entire population, but some nutrients have not been calculated (males: 38g fiber, females 25g fiber).
Adequate Intake (AI)
Meets needs of a smaller population, prevents deficiency, but doesn’t provide optimal function.
Estimated Average Requirement (EAR)
Meets half of the population’s requirements.
Upper Intake Level (UL)
Highest level of a daily nutrient to show no adverse effects. Not a goal, but an extreme (not calculated for some nutrients).
Chronic Disease Risk Reduction (CDRR)
Takes risk of chronic disease into account and varies depending on individual’s family/medical history.
Acceptable Macronutrients Distribution Ranges (AMDR)
Distribution ranges of recommended intakes, associated with reduced risk of disease.
Carbs: 45-65%
Protein: 10-35%
Fat: 20-35%
Estimated Energy Requirement (EER)
The amount of calories your body needs in a day.
Daily Value (DV)
Nutrition facts reflecting the needs of an “average” person or someone eating 2,000 kcal/day.
Dietary Guidelines
Nutrition-related lifestyle recommendations (food or physical) intended for healthy people across the lifespan in order to promote health and reduce disease risk. Updated every 5 years by nutrition experts, the public, and the government.
Major Guildlines
Follow a healthy pattern
Customize and enjoy nutrient-dense foods that reflect your personal preferences
Focus on meeting food group needs
Limit foods/beverages high in added sugar, saturated fat, sodium, and alcohol (know these limits)
Nutrient Density
Amount of nutrients within a food in relation to food’s weight.
Energy Density
Amount of energy (kcal) within a food in relation to the food’s weight.
Added Sugar Limit
<10% of kcal/day
Saturated Fat Limit
<10% of kcal/day
Sodium Limit
<2300 milligrams/day
Under-consumed Nutrients
Calcium, potassium, fiber, and vitamin D
Average Food Group Requirements
Fruit: 2 cups
Vegetables: 3 cups
Grains: 8oz
Protein: 6 1/2oz
Dairy: 3 cups
Grains
Any food made from wheat, rice, oats, cornmeal, barley, \n or other cereal grain. Contain fiber, vitamin B, complex carbohydrates, protein, and sometimes fat.
Enrichment
Adding nutrients back to a food to return content to original levels after processing.
Fortification
Addition of nutrients above what natural food normally contains.
Whole Grains
Contain the entire kernel of grain (the bran, germ, and endosperm), which is rich in nutrients.
Refined Grains
Grains that have been milled which removes fiber, iron, and B vitamins.
Diary
Milk/milk products that contain calcium; protein, calcium, phosphorus, riboflavin, zinc, potassium, B12. Need vitamin D to absorb calcium.
Meat/Protein
Provides iron, zinc, niacin, thiamin, riboflavin, B6, vitamin E. Better to consume lean protein sources for heart health. Protein found in meat, fish, eggs, soy products, legumes, beans, dairy, and some grains.
Fruits
Fruit or 100% fruit juice; fresh, frozen, canned, whole, cut, pureed, or dried/juiced (may contain sugar). Provide fiber, folate, vitamin A, potassium, and vitamin C.
Vegetables
Can be fresh, cooked, canned, frozen, dried/dehydrated, juiced, cut, whole, mashed; good source of micro nutrients and phytochemicals.
Whole Foods
Food that has not been processed or refined (transformation of raw ingredients into food, or food into other forms). However, processing is not always bad.
Healthy Diet Contents
Variety of fruits & vegetables
At least half your grains are whole grains
Low-fat dairy products
Variety of protein foods
Oils instead of solid fats
Serving Size
FDA stablished amount that is meant to reflect what people customarily consume.
Ingredient List
Lists all ingredients on label in descending order of predominance by weight.
Gastrointestinal (GI) Tract
Series of organs arranged in long tube that works together to process foods.
Consumption
Digestion
Absorption
Metabolization
Distribution
Excretion
Digestive System
Breaks food down to its nutrient components and absorbs/delivers nutrients to bloodstream for distribution.
Esophagus
Stomach
Small Intestine
Colon
Digestion
Extracts and breaks down nutrients into smaller units that can be absorbed into intestinal walls/delivered in bloodstream; mechanical or physical. (mostly in duodenum)
Mastication
Chewing (physical digestion), salivary amylase (chemical digestion)
Peristalsis
The involuntary constriction and relaxation of the muscles of the intestine; stimulated by swallowing.
Stomach
Holds ingested food ~4-6 cups, empties every 2-4 hours, strongest muscles in GI tract, secretes intrinsic factor. Contains gastric lipase and pepsin.
Chyme
Mixture of bolus and gastric juice located in stomach.
Gastrin
Stimulates stomach to release secretions.
Bicarbonate
Mucus; protects stomach from acid and moistens food.
Gastric Acid (HCl)
Unfolds proteins, kills bacteria, and activates pepsin.
Pyloric Sphincter
Empties stomach contents into small intestine.
Small Intestine
16-20 ft long, major digestive site, 3 sections (duodenum, jejunum, and ileum). Mesentery holds blood/lymph vessels that absorb nutrients. Digestive juices: mucus (goblet cells), digestive enzymes (pancreas), hormones, bicarbonate ions (pancreas), and bile (made in liver, stored in gall bladder).
Gastric–inhibitory peptide (GIP)
Made to slow down the stomach secretions and GI mobility.
Secretin
Stimulates pancreatic secretions.
Cholecystokinin (CCK)
Stimulates gall bladder to release bile/pancreatic secretions, slows GI mobility, and reduces food intake.
Accessory Organs
Liver, gall bladder, and pancreas. Food does not actually travel through these organs.
Pancreas
Produces digestive enzymes such as:
Proteases
Lipase
Amylase
Bicarbonate Ions
Absorption
Movement of compounds from GI tract and small intestine lumen into bloodstream. (mostly in jejunum)
Enterocytes
Absorptive cells that line/cover the lumen of the small and large intestines.
Lumen
Open space in the center of the small intestine.
Microvilli
Projections (waves) of the luminal cell membrane that trap nutrients, finish digestion, and begin absorption.
Villi
Projections of the epithelial cell layer/lining of the intestines that is covered with enterocytes; most concentrated in the jejunum.
Mucosal Folds
Folds (plicae) in the epithelial lining of the intestines; most concentrated in the jejunum.
Water-Soluble Nutrients
Monosaccharides, amino acids, minerals, small lipids, B vitamins and vitamin C enter the blood through arteries in the intestines.
Hepatic Portal Vein
Vein that connects the intestines and liver. Oxygenated blood drops off oxygen at the intestines and picks up nutrients for the liver.
Fat-Soluble Nutrients
Larger fats, Fat-soluble vitamins (vitamins A,E,D,K) enter through lymphatic system and bypass the liver straight to larger veins in the chest.
Large Intestine
5-6 feet long, contains the colon, rectum, and tons of good bacteria. Does not have villi so not as much absorption occurs (except for water, vitamin k, sodium, potassium, chloride).
Gut Microbiome
Entirety of bacteria living within intestine (mostly large intestine) of an organism. Probiotics contain good bacteria that makes vitamins, protect against harmful bacteria.
Liver
Makes amino acids, de-toxifies, helps break things down, stores vitamins, forms lymphatic system, forms bile, and forms blood clotting materials.
Cholestasis
Inability to make bile, and as a result, digest fat.
Malabsorption
Inability to absorb something.
Gastroesophageal Reflux Disease (GERD)
AKA heart burn, when stomach contents are pushed up into the esophagus.
Inflammatory Bowel Disease (IBD)
Group of diseases that causes intestinal inflammation/swelling. Damages intestinal epithelium and disrupts digestion/absorption.