energy balance
the state in which energy intake, in the form of food and beverages, matches the energy expended, primarily through basal metabolism and physical activity
positive energy balance
the state in which energy intake is greater than energy expended, generally resulting in weight gain
negative energy balance
the state in which energy intake is less than energy expended, resulting in weight loss
uses of energy by the body
1. basal metabolism
2. physical activity
3. digestion, absorption, and processing of ingested nutrients
4. adaptive thermogenesis
adaptive thermogenesis
the ability of humans to regulate body temperature within narrow limits; examples are fidgeting and shivering
components of a sound weight-loss program
rate of loss; flexibility; intake; behavior modification; overall health
weight-loss triad
1. controlling calorie intake
2. performing regular physical activity
3. engaging in positive behaviors
physical activity recommendations
150 minutes a week of moderate aerobic activity for adults or something equivalent; 60 minutes a day for children; some exercise is better than no exercise at all
vitamin
an essential organic (carbon-containing) compound needed in small amounts in the diet to help regulate and support chemical reactions and processes in the body; cannot be synthesized in the body; conezymes to enzymes (proteins)
the two classes of vitamins
fat-soluble vitamins and water-soluble vitamins
fat-soluble vitamins
vitamins that dissolve in fat and such substances as ether and benzene but not readily in water; these are vitamins A, D, E, and K
water-soluble vitamins
vitamins that dissolve in water; these are the B vitamins and vitamin C
mineral
element used in the body to promote chemical reactions and to form body structures; cannot be broken down further; 16 minerals are essential; cofactors to enzymes (proteins)
categories of minerals
major minerals and trace minerals
major mineral
vital to health, a mineral that is required in the diet in amounts greater than 100 milligrams per day; there are seven essential major minerals (calcium, phosphorous, magnesium, sulfur, sodium, potassium, and chloride)
trace mineral
vital to health, a mineral that is required in the diet in amounts less than 100 milligrams per day; there are nine essential trace minerals (iron, zinc, copper, iodine, selenium, molybdenum, fluoride, manganese, and chromium)
ultratrace mineral
a mineral present in the human diet in trace amounts but that has not been shown to be essential to human health; these include arsenic, boron, nickel, silicon, and vanadium
functional foods
foods that have health benefits beyond basic nutrition; examples are oatmeal or calcium-fortified orange juice
two categories of functional foods
zoochemicals and phytochemicals
zoochemicals
chemicals found in animal products that have health-protective actions
phytochemicals
chemicals found in plants that have health-protective actions; responsible for the unique colors, flavors, and odors observed in plants; benefits range from reducing inflammation to inhibiting the initiation and proliferation of cancer; rich sources of ph
basic functional roles of micronutrients
acting as enzymes, coenzymes, and cofactors; fluid and electrolyte balance; body defenses from pathogens; bone health; energy metabolism; blood and brain health
digestion, absorption, and storage of vitamins
fat-soluble vitamins are absorbed along with dietary fat, carried through the bloodstream, and are mainly stored in the liver and fatty tissues; the B vitamins (water-soluble) are broken down into free vitamins first; water-soluble vitamins are absorbed i
digestion, absorption, and storage of minerals
components of fiber can limit absorption of minerals by binding to them; minerals of similar sizes and charges compete with each other for absorption; some vitamins can improve absorption of certain minerals; minerals from animal products are better absor
vitamin toxicity
most water-soluble vitamins are filtered by the kidney and readily excreted by the body, except for vitamin B-6 and B-12 which are stored in the liver and can reach toxic levels; fat-soluble vitamins are not readily excreted by the body and can reach toxi
mineral toxicity
trace minerals are especially subject to reaching toxic levels
preservation of minerals in food
minerals are not typically lost from animal sources; the more refined a plant food, the more minerals lost; suggestion is to "make half your grains whole
preservation of vitamins in food
the riper a food, the more vitamins it will have; water-soluble vitamins can be destroyed by improper storage or excessive cooking; factors that can destroy vitamins are heat, UV light, exposure to oxygen, cooking submersed in water, and alkalinity; freez
functions of water
temperature regulation; distribution of nutrients; lubricant; chemical reactions; acid-base balance; component of body fluids; removal of waste products; also the "universal solvent
factors that contribute to development of hypertension
obesity, inactivity, alcohol intake, excess salt intake, age, and genetics
electrolyte
a mineral that separates into positively or negatively charged ions in water; able to transmit an electrical current;
four important electrolytes
sodium (extracellular) found mainly in food manufacturing and preparation, AI is 1300 milligrams; chloride (extracellular) found in some fruits and vegetables, but mostly in salt, AI is 2300 milligrams; potassium (intracellular) found in unprocessed foods
control mechanisms that regulate water intake and output
receptors in the kidneys, blood vessels, and brain monitor blood pressure and water availability; when too high or too low, hormones or enzymes will be released to counteract
oxidation
the process of losing an electron during a chemical reaction
reduction
the process of gaining an electron during a chemical reaction
how antioxidants neutralize free radicals
antioxidant enzymes convert harmful free radicals into less damaging compounds at specific locations within cells; antioxidant chemicals are derived from foods and donate an electron or hydrogen atom to reactive molecules, the antioxidant will become unst
free radical
an unstable atom with an unpaired electron in its outermost shell; chemically reactive and sometimes aggressive; to stabilize, the atom steals an electron from a neighboring atom and it starts a chain reaction; production of free radicals is helpful to a
functions of vitamin C
also known as ascorbic acid or ascorbate; a powerful antioxidant; reactivates vitamin E after it has donated an electron to a free radical; stimulate proliferation of white blood cells; role in the synthesis of collagen; important for wound-healing; role
food sources of vitamin C
lemons, oranges, limes, citrus fruits, broccoli, cauliflower, peppers, breakfast cereals, potatoes, fortified fruit drinks; the brighter the fruit or vegetable, the higher it tends to be in vitamin C; can be lost easily in processing and cooking; RDA is 9
signs and symptoms of vitamin C deficiency and toxicity
deficiency: called scurvy; symptoms include bleeding gums, tooth loss, bruising, and scaly skin; skin and blood vessels will weaken and wounds will not heal
toxicity: kidneys will excrete excess vitamin C (over 100 milligrams a day); symptoms (over 2000 m
functions of vitamin A and carotenoids
health of epithelial cells and immune function; vision; growth, development, and reproduction; cardiovascular disease prevention; cancer prevention
carotenoids def.: precursors of vitamin A found in plant foods (retinoids, or vitamin A's group, is found i
food sources of vitamin A
retinoids: liver, fish, fish oils, fortified milk, butter, yogurt, eggs, margarine
carotenoids: dark-green and yellow-orange vegetables and some fruits (carrots, spinach, mangoes, broccoli, sweet potatoes, peaches)
RDA is 900 micrograms RAE for men and 70
signs and symptoms of vitamin A deficiency and toxicity
deficiency: most Americans have an adequate intake of vitamin A; those at risk for deficiency include those who do not consume vegetables, alcoholics, people with severe fat-malabsorption
toxicity: for retinoids, linked to birth defects and liver toxicity
the role of antioxidant phytochemicals
found in fruits and vegetables; lowers oxidative stress; positive effects on chronic diseases; we use the ORAC (oxygen radical absorption capacity) method to rank antioxidant foods
physiology of bone
periosteum: a specialized connective tissue covering all bones and having bone-forming potential
cortical bone: the compact or dense bone found on the outer surfaces of bone
trabecular bone: the less dense, more open structure bone found in the inner laye
bone synthesis and degradation
bone remodeling: the chemical process by which bone is broken down and replaced by new bone; osteoclasts degrade small amounts of bone and release minerals into the bloodstream; osteoblasts embed within resorption bay and pick up minerals to add strength
factors that influence bone health
biological - after 30 years, bone mineral density begins to decrease; bone loss accelerates after menopause; frame size and ethnicity are other factors
lifestyle - a balanced dietary patterns; healthy weight and active lifestyle; increased muscle mass is
functions of calcium
all cells require calcium to function; forming and maintaining bone is the major role; muscle contraction and verve transmission; and much more
sources of calcium
primarily dairy products; bread, rolls, crackers, and foods made with dairy products; leafy greens, almonds, some legumes, sardines, and canned salmon
RDA is 1000 milligrams per day; many people fall below this
functions of vitamin D
the only nutrient that is also a hormone; only nutrient that can be produced in the skin upon exposure to ultraviolet light; main function is to maintain the normal range of calcium and phosphorous in the blood; also involved in gene expression and cell g
sources of vitamin D
sunlight is the best source; fatty fish, other fish, eggs, mushrooms, fortified foods (ready-to-eat breakfast cereals)
RDA is 15 micrograms
signs and symptoms of vitamin D deficiency
called rickets when in children, called osteomalacia in adults; leads to decrease in bone mineral density and bones are at risk for fracture
vitamins and minerals in metabolism
the B vitamins and some minerals play key roles in metabolism as coenzymes (vitamins) and cofactors (minerals)
functions of thiamin
thiamin is vitamin B-1; help release energy from carbohydrate; also functions in chemical reactions that make RNA, DNA, and neurotransmitters
sources of thiamin
pork products, whole grains, ready-to-eat breakfast cereals, enriched grains and flours, green beans, milk, orange juice, organ meats, peanuts, dried beans, and seeds
signs and symptoms of thiamin deficiency
called beriberi (means "I can't, I can't"); characterized by muscle weakness, deep muscle pain in calves, loss of appetite, nerve degeneration, poor arm and leg coordination, and sometimes edema
functions of vitamin B-6
called pyridoxine; primary function is as a coenzyme in over 100 chemical reactions that involve the metabolism of amino acids and protein; also plays a role in homocysteine metabolism, synthesis of neurotransmitters, conversion of tryptophan to niacin, b
sources of vitamin B-6
major sources are animal products and fortified ready-to-eat breakfast cereals; also fruits and vegetables (potatoes, spinach, bananas, and cantaloupe); heating and freezing can easily destroy it
RDA is 1.7 milligrams for men and 1.3 milligrams for women
signs and symptoms of vitamin B-6 deficiency
deficiency would affect multiple body systems; symptoms include depression, vomiting, skin disorders, irritation of the nerves, anemia, and impaired immune response
functions of iodine
the thyroid gland actively accumulates and traps iodine from the bloodstream to support thyroid hormone synthesis
sources of iodine
iodized salt (some countries require this), dairy products, and grain products
RDA is 150 micrograms; North Americans typically overconsume but some worry is for vegans
signs and symptoms of iodine deficiency
goiter: an enlargement of the thyroid gland, often caused by insufficient iodine in the diet; can cause difficulty breathing
congenital hypothyroidism: a birth defect that impairs thyroid hormone synthesis; can lead to mental retardation and stunted growt
functions of vitamin K
a cofactor in chemical reactions that add carbon dioxide molecules to various proteins thus enabling these proteins to bind calcium - important for blood clotting and bone health
sources of vitamin K
green leafy vegetables, broccoli, asparagus, and peas; some meats, eggs, and dairy products; is resistant to cooking losses
AI is 120 micrograms for men and 90 micrograms for women
signs and symptoms of vitamin K deficiency
deficiencies rarely occur; common in newborns because they have a sterile gut (injections shortly after birth are recommended); can occur when a person takes antibiotics for an extended time or when fat absorption is limited
signs and symptoms of vitamin K toxicity
no reports of toxicity have been published
functions of folate
folate: term to describe a variety of vitamin B-9 forms found in foods and in the body
folate coenzymes supply or accept single carbon compounds to help form DNA and metabolize amino acids; metabolizes homocysteine; formation of neurotransmitters
sources of folate
richest sources are green leafy vegetables; also other vegetables, orange juice, dried beans, and organ meats; for folic acid: fortified ready-to-eat breakfast cereals, bread, and milk
signs and symptoms of folate deficiency
megaloblastic anemia: anemia characterized by the presence of abnormally large [and immature] red blood cells; symptoms include inflammation of the tongue, diarrhea, poor growth, mental confusion, depression, and problems in nerve function
functions of vitamin B-12
most important is participating in folate metabolism; also maintaining the myelin sheath that insulates neurons
process of vitamin B-12 absorption
vitamin B-12 is bound to food; R-proteins are released from salivary glands and travels with food to the stomach; acid and enzymes release vitamin B-12 from food, vitamin B-12 binds with R-proteins; stomach releases intrinsic factor; when food reaches the
sources of vitamin B-12
organ meats, meat, seafood, ready-to-eat breakfast cereals, milk, and eggs
RDA is 2.4 micrograms per day; adults usually consume twice the RDA
signs and symptoms of vitamin B-12 deficiency
pernicious anemia: the anemia that results from a lack of vitamin B-12 absorption; symptoms include sore mouth, depression, back pain, apathy, and severe nerve degeneration; can lead to paralysis and death
inadequate intake of vitamin B-12 is usually not
functions of iron
part of hemoglobin in red blood cells; part of myoglobin in muscle cells; used as part of many enzymes, some proteins, and compounds; needed for brain and immune function, drug detoxification in liver, and synthesis of collagen
sources of iron
ready-to-eat breakfast cereals, beans, and animal products; added to flour in the enrichment process
RDA is 8 milligrams per day for men and 18 milligrams per day for pre-menopausal women (8 after)
signs and symptoms of iron deficiency
iron deficiency is the most common deficiency around the world; categorized into three categories; symptoms include pale skin, fatigue upon exertion, poor temperature regulation, loss of appetite, and apathy; can decrease learning ability, attention span,
signs and symptoms of iron toxicity
consuming amounts above the UL (45 milligrams per day) can lead to gastric distress
hemochromatosis: a disorder of iron metabolism characterized by increased iron absorption and deposition in the liver and heart; this eventually poisons the cells in those
positive health-related outcomes of a physically active lifestyle
enhanced heart function, less injury, better sleep habits, improvement in body composition; reduce stress and positively affect blood pressure, blood cholesterol, blood glucose regulation, and immune function; aids in weight control; ability to mobilize f
how athletes can optimize performance (nutrition-wise)
before the event: focus on maximizing muscle and liver glycogen stores
during the event: prevent dehydration and glycogen depletion
after the event: replenish muscle glycogen stores, repair damaged muscle tissue, restore hydration
problems associated with weight loss by dehydration
losing as little as 2% of body weight by dehydration can adversely affect physical and mental performance; can lead to kidney malfunction, heat-related illness, and death
how to estimate an athlete's calorie needs
calorie needs are highly individualized depending on genetics, hormones, age, sex, body size and composition, and training; 5 to 8 kcal per minute is needed to sustain moderate activity
generally principles for meeting overall nutrient requirements in training
carb-loading before an event; intake recommendation depends on intensity of workout; moderate intake of fiber last day of training; diet with 35% of calories for fat is recommended; 1.2 to 2 grams of protein per kilogram of body weight; vitamins and miner
physical and mental characteristics of anorexia nervosa
anorexia nervosa: an eating disorder characterized by extreme restriction of energy intake relative to requirements leading to significantly low body weight; three criteria are extreme weight loss, irrational fear of weight gain, and distorted body image;
current best practices for treating anorexia nervosa
nutritional therapy - goal is to restore body weight to a healthy range; teaching appropriate food habits
psychological therapy - discovering triggers; regaining control of other facets of life and coping with difficult situations
pharmacological therapy
physical and mental characteristics of bulimia nervosa
bulimia nervosa: an eating disorder characterized by recurrent episodes of binge-eating followed by inappropriate compensatory (binging) behaviors to prevent weight gain; often have regular or slightly higher body weight; lead secret lives; impulsive; hal
current best practices for treating bulimia nervosa
nutritional therapy - two goals are reestablishing regular eating habits and correcting misconceptions about food; avoiding binge foods and other behavioral techniques
psychological therapy - improve self-acceptance and become less concerned about body we
physical and mental characteristics of binge-eating disorder
binge-eating disorder: an eating disorder characterized by recurrent episodes of binge-eating that are associated with marked distress and lack of control over behavior, but not followed by inappropriate compensatory behaviors to prevent weight gain; tend
current best practices for treating binge-eating disorder
nutritional therapy - developing normal eating patterns and healthful food choices; eat in response to hunger, not emotions; respond to prescribed amount of fullness; avoid losing weight right away because deprivation can be a trigger
psychological therap
methods to reduce development of eating disorders
discourage restrictive dieting and meal skipping; encourage normal expression of disruptive emotions; increase self-acceptance; build respectful environments and supportive relationships; correct misconceptions about nutrition, healthy body weight, and ap
current hypotheses about origins of eating disorders
dysfunctional family interactions; genetics; history of abuse; epigenetics
hunger
the primarily physiological (internal) drive to find and eat food
malnutrition
failing health that results from longstanding dietary practices that do not coincide with nutritional needs
undernutrition
failing health that results from a longstanding dietary intake that is not enough to meet nutritional needs
consequences of undernutrition during critical periods
pregnancy - high maternal mortality rates; passing deficiencies onto newborns
fetal and infant stages - delayed development; preterm births and low birth weights
childhood - central nervous system is highly vulnerable; damage in this time is irreversible;
undernutrition in the developing world
caused by poor infrastructure, AIDS, war and political/civil unrest, extreme imbalances in food-population ratio, high foreign debt, and rapid depletion of natural resources,
possible solutions (and barriers to solutions) in the developing world
Millennium Declaration was in place from 2000-2015 and adopted by UN; now we have the 17 UN Sustainable Development goals; the biggest problem is that the problems that feed into undernutrition are complex and unique
types and common sources of fungi, bacteria, viruses, and parasites
fungi -
bacteria -
viruses -
parasites -
food-preservation methods
dehydration, fermentation, pasteurization, sterilization, refrigeration, freezing, canning, chemical preservation, and food irradiation
foodborne illnesses caused by bacteria, viruses, and parasites
bacteria - three ways (foodborne infection, toxin-mediated infection, and foodborne intoxication)
viruses -
parasites -
procedures to limit risk of foodborne illnesses
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pesticide use: reason for it, long-term health complications, and safety limits
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