HAN 461 Final review , Metabolic Pathways and Vitamin Functions Overview

Disordered eating

Fat free mass

the weight of the body that includes body water, bones, teeth, muscles, and organs

Two-component model

method of measuring body composition that divides the body into two compartments: fat mass and fat-free (lean) mass

Subcutaneous fat

Deposits of adipose cells in the tissue under the skin

It helps to:

Insulate the body against cold temperatures

■ Protect muscles and bones from being jostled during impact

○ There are sex differences in the thickness and distribution of this fa layer.

Visceral Fat

Deposits of adipose tissue that surround abdominal organs

Dual-energy x-ray absorptiometry (DXA)

technique of estimating body composition that involves scanning the body with two low-energy x-rays

○ It is highly accurate. GOLD STANDARD

○ But it is very expensive and not widely available

Central Body Obesity

Storage of excess body fat in the upper body or abdominal region, leading to an "apple shape"

● Increases risk of CVD, hypertension, and type 2diabetes

Total energy expenditure (TEE) -

amount of energy needed for all bodily functions throughout the day

Basal Metabolism

minimum amount of energy needed to maintain the body's vital functions while at rest

basal metabolic rate (BMR)

measurement of basal metabolism

○ Done after a 12-hr fast, while lying motionless in a temperature-stable environment

○ Basal metabolism includes breathing, circulating blood, and maintaining function of vital organs such as the liver, brain, and kidneys

○ Basal metabolism does NOT include the energy needed for skeletal muscle movements (physical activity), digestion of food, or absorption and processing of nutrients

Resting Metabolic Rate (RMR)

body's rate of energy use after resting and eating

○ A person's RMR is about 10% higher than their BMR

Factors That Decrease BMR

• Starvation or very-low-calorie diets

• Insufficient thyroid hormone levels

• Aging

• Less body surface area(short)

Non exercise activity thermogenesis (NEAT)

energy expended during spontaneous, unplanned physical activities; it includes:

○ Involuntary movements, such as shivering, that produce less movement and more heat

○ Voluntary movements like fidgeting, maintaining an up right body position, or performing light activities such as cooking and cleaning

The thermic effect of food (TEF)

energy used to digest foods and beverages as well as absorb and further process the macronutrients

■ Generally 5 to 10% of total caloric intake26

Accelerometry

method of measuring calorie expenditure during physical activity based on changes in speed and direction

Hypothalamus

structure in the brain that controls hunger and satiety

Ghrelin

hormone secreted by the stomach and other tissues that stimulates eating

Amylin

hormone secreted by the pancreas that slows gastric emptying and reduces hunger

Leptin

hormone secreted by the adipose tissue that reduces hunger and increases energy expenditure

• Leptin resistance - unresponsiveness to leptin observed in obesity

Cushing's syndrome

chronically elevated blood cortisol levels

Obesogenic environment

external conditions that promote excessive weight gain

Recommended weekly physical activity to promote weight maintenance in healthy adults

■ At least 150 minutes of moderate-intensity or at least 75 minutes of vigorous-intensity

genetic risk score (GRS)

■ A cumulative genetic score that provides impact of all the various obesity genes

■ Genotyping healthy individuals in this way to assess risk is not warranted

■ Certain genetic defects cause severe, early-onset obesity

Carbohydrate-insulin model

Theory of obesity in which carbohydrate intake increases blood insulin to levels that cause fataccumulation41

Seasonal affective disorder (SAD)

mood disorder that occurs at the same time every year; "winter depression"

• Occurs in the winter months and at higher latitudes where sun exposure is low

○ Associated with weight gain, Vitamin D deficiency, which can occur due to low sun exposure, also increases risk of obesity

Weight-Loss Medications

■ One drug acts as a lipase inhibitor, reducing fat digestion by about 30%(also reduces absorption of fat-soluble vitamins)

■ One drug combines phentermine (suppresses appetite) and topiramate(used to treat seizures and migraines)

■ Other active ingredients include naltrexone (used to treat alcoholism)and bupropion (an antidepressant) 47

Bariatric medicine

medical specialty that focuses on the surgical treatment of obesity. They drastically reduce the size of the stomach, markedly limiting a person's food intake. NOT A CURE

Roux-en-Y gastric bypass

surgical approach to treating obesity where part of the intestine is bypassed

Disordered Eating

refers to chaotic and abnormal food-related practices such as skipping meals, limiting food choices, following fad diets, and binge eating

Eating Disorders

are psychological disturbances that lead to certain physiological changes and serious health complications

Anorexia nervosa (AN)

a severe psychological disturbance characterized by self-imposed starvation

○Results in malnutrition and emaciation

■ Emaciation refers to very low body weight. More in females

Bulimia nervosa (BN)

Is a severe psychological condition characterized by repeated episodes of binge eating followed by unhealthy behaviors to prevent weight gain

Binge-eating disorder (BED)

is an eating disorder characterized by recurrent episodes of binge eating that are not followed by purging behaviors

Menarche

The onset of the first menstrual cycle

Amenorrhea

the cessation of menstruation for 3months or longer68

hypokalemia

The rapid loss of electrolytes and fluid due to self-induced vomiting and diuretic abuse

○ Low blood levels of potassium that can cause serious cardiac arrhythmias and skeletal muscle damage

night eating syndrome (NES)

experience episodic food binges after evening meal or after waking up that are not followed by purging

● People with NES may consume 50% of their total daily calorie intake after the evening meal.

Diabulimia

practice in which people with type 1 diabetes manipulate their bodyweight by skipping insulin injections or using less insulin than prescribed.

Complications include: Blindness, Kidney failure, Blood vessel diseases, Diabetic ketoacidosis

Orthorexia nervosa (ON)

is a condition characterized by an extreme obsession with eating healthy foods

Drunkorexia

Highly physically active college students are more likely to binge drink than their less active peers

○ Individuals who binge drink may use exercise or fasting as a way to compensate for the extra calories consumed during a night of heavy drinking

Cognitive behavioral therapy (CBT)

psychological treatment approaches that addresses unhealthy behavior by challenging current beliefs and replacing them with more realistic thoughts Dialectical behavioral therapy

Dialectical behavioral therapy (DBT)

- form of psychotherapy that strives to improve skills used to manage stress, anxiety, or feelings of inadequacy88

The preconception period

is the 3-month time before pregnancy, Having adequate nutrient stores in the body before pregnancy begins.

○ Much important development occurs very early in pregnancy Many females are unaware that they are pregnant until 6 to 8 weeks of gestation

Infertility

the failure to conceive after 12 months of trying to become pregnant

● About 20% of females ages 15 to 49 years experience

micronutrients are also relevant to fertility

Adequate status of folate, iron, and vitamin D are important in female egg production

Protein Needs In pregnancy

The RDA for protein during pregnancy is 71 g protein ∕ day

● Females who consume plant-based diets that include dairy and eggs appear to have ample protein intakes

● It may be difficult for females following a vegan diet to consume the RDA for protein

Fatty acids needs in pregnancy

the DRI for the essential fatty acids increase as follows:

● For alpha-linolenic acid, from 1.1 to 1.4 g ∕ day

● For linoleic acid, from 12 to 13 g ∕ day

Vitamin D In pregnancy

The RDA for vitamin D during pregnancy is 15 μg ⁄ day

○ Females who are pregnant are encouraged to get plenty of sunlight exposure

Folate for pregnancy

Adequate levels of folate are essential for proper development of the neural tube

○ A structure that becomes the brain and spinal cord and forms prior to the fourth week of gestation

○ Low intake of folate during the preconception period can lead to neural tube defects (NTDs)

Vitamin A for pregnancy

It is important for pregnant females to consume:

● Preformed vitamin A, such as in dairy and butter

● Beta-carotene found in many orange vegetables, such ascarrots and sweet potatoes

● Vitamin A supplementation is not recommended

Iron for pregnancy

The RDA for iron increases from 18 mg to 27 mg for female who is pregnant (as compared to female who is not pregnant)

Additional iron is needed to:

○ Support increased maternal hemoglobin synthesis

○ Transfer iron to the developing offspring for production of its own hemoglobin

Iodine for pregnancy

The RDA for iodine increases from 150 μg to 220 μg for female who is pregnant (as compared to female who is not pregnant)

○ The body needs iodine to synthesize thyroid hormone, which is critical for normal fetal brain development

■ Children born to mothers who had severe iodine deficiency during pregnancy are at risk of congenital hypothyroidism

Calcium in pregnancy

The RDA for calcium does not increase during pregnancy, as absorption in the GI tract increases

○ Many females, however, do not consume enough calcium-rich foods

■ In the third trimester, fetal bone mineralization occurs at a rapid rate

○ It is important for females to enter pregnancy with ample calcium reserves

○ Food sources include:

■ Dairy products

■ Green leafy vegetables such as cooked kale and broccoli

Pica

Some people, especially pregnant females, crave and eat nonfood items, such as dirt, clay, or laundry starch, on a regular basis

caffeine in pregnancy

Females should limit their caffeine consumption to less than 200 mg ∕ day during pregnancy

Hypertension and Swelling in Pregnancy

S/Sx: Swelling in the ankles/lower body or in the face and hands. Hypertension is among the leading causes of:

■ Maternal death

■ Preterm labor

■ Complications that affect the newborn infant

○ Gestational Hypertension - when a woman is diagnosed with elevated blood pressure for the first time after 20weeks of gestation and BP returns to normal within 12 weeks of labor

Preeclampsia

a condition often associated with maternal kidney and liver damage

● Most cases begin after the 20th week of pregnancy

● The direct cause is unknown

● Can be deadly for the fetus and mother.

Anemia of Pregnancy

●Hematocrit is the ratio of red blood cells to total blood volume. There are two main causes of anemia during pregnancy:

● Expansion of maternal blood volume

● Poor dietary intake of iron

●When a mother is found to be anemic she is put on an iron supplement that is 30-60mg/day of iron depending on the severity

Low birth weight (LBW) -

a birth weight that is less than 2,500 g (5.5 lb)

Risk factors:

● Not gaining the recommended minimum weight during pregnancy

○ Can result in a poorly developed placenta (fewer nutrients reach the fetus)

● Anemia

●preeclampsia

High birth weight (HBW) -

birth weight that is greater than 4,000 g (approximately8.8 lb)

○ Often require birth by cesarean section (C-section), the surgical removal of the baby from the mother's uterus

Colostrum

- form of milk that is secreted from a female's breast during the first few days after birth

Transitional milk

- combination of colostrum and mature milk

○ Produced by the end of the first week

○ Higher in lactose than colostrum

Mature milk

- form of milk that is secreted about 2 weeks after delivery

○ Higher in fat, carbohydrates, certain amino acids, and vitamins

Carbohydrates in breast milk

Lactose and oligosaccharides

● Human milk oligosaccharides (HMOs)

○ Complex, chemically unique sugar molecules with bioactive properties

■ Antibacterial activity: Prevents pathogen colonization

■ Natural prebiotics: Promote the growth of beneficial bacteria in the largeintestine

Lipids in breast milk

Delivered in a unique package, similar in structure to lipoproteins:

● Milk fat globule (MFG) delivers in highly bioavailable form:○ Triglycerides

○ Phospholipids

○ Cholesterol

○ Fat-soluble vitamins

Protein in breast milk

● Whey is milk protein that is water-soluble and quickly digested

● Casein is milk protein that is water-insoluble and slowly digested

Colostrum contains about 21 g ∕ L of protein

○ About 90% whey and 10% casein

Mature human breast milk contains about 11 g ∕ L of protein○ About 60% whey and 40% casein

Hypoallergenic formulas

a class of infant formula containing predigested protein that has been hydrolyzed to polypeptides and free amino acids

○ An alternative to soy-based formulas

Amino acid formulas

a class of infant formula containing protein that has been hydrolyzed completely to free amino acids

○ An option for infants with severe allergies or who refuse hydrolyzed formulas due to poor taste

Foods to Avoid During Infancy

○ Honey may contain spores of Clostridium botulinum

○ Regular cow's or goat's milks and plant-based milk alternatives should not replace human milk or formula

○ Nonfat foods are often high in refined carbohydrates and poor sources of healthy fats critical for development

○ Ultra-processed foods can lead to deficiencies and increase the risk of chronic disease in adulthood

○ Small pieces of hard or coarse foods can cause choking

Children RDA for protein is

● 13 g ∕ day for toddlers

● 19 g ∕ day for preschool-age children

Children AI for fiber is:

○ 19 g ∕ day for children 1 to 3 years

○ 25 g ∕ day for children 4 to 8 years

Age ranges

Toddler - child who is 1 to 3 years of age

Preschool-age - child who is 3 to 5 years of age

School-age - child who is 6 to 11 years of age

Adolescence - period of life that begins at puberty and ends at adulthood (age 12-19)

Senescence

declining organ functioning that occurs with advanced age

Older Population EAR for energy is:

○ 2,000 kcal for older males

○ 1,600 kcal for older females

Sarcopenia

Weight loss after age 70 years is partially a result of the loss of muscle mass (sarcopenia)

○ Contributes to functional decline, frailty, falls, poor quality of life, and in some cases, death

Sarcopenic obesity

type of obesity that is characterized by theloss of skeletal muscle mass combined with excessive body fat

Presbyopia Cataract

decline in near vision that occurs with aging

Cataract

condition characterized by abnormal changes in the lens of the eye that can cause blindness

Edentulism

condition characterized by the loss of all teeth

Xerostomia

dry mouth

Osteoarthritis

condition characterized by degeneration of the bones and cartilage

Gout

form of arthritis caused by buildup of uric acid crystals in joints

Uric acid

- derivative of purine metabolism

Heart failure (HF)

is a condition in which the heart cannot pump effectively

○ Signs and symptoms include

■ Shortness of breath

■ Fatigue

■ Edema, especially in legs

Polypharmacy

is the simultaneous use of multiple medications to treat one or more health conditions

Reduce Alzheimer's

○ Eating foods that are rich sources of omega-3 fatty acids

○ Being physically active

○ Keeping intellectually and socially active

Health and Human Services

Engage in at least 150 minutes of moderate-intensity, or at least 75minutes of vigorous-intensity, aerobic physical activity per week

● Perform muscle-strengtheningactivities at least 2 days/wk

Max heart rate

subtract a person's age from 220

PCr-ATP system

■ high-energy compound used to re-form ATP under anaerobic conditions; provides energy for short bouts of high-intensity activity

Oxygen system

■ When muscle cells have plenty of oxygen available and sufficient time, they can metabolize glucose completely to CO2 and H2 O

Lactic Acid Energy System

When physical activity lasts longer than a few seconds, the PCr-ATP energy system cannot keep up with energy demands

○ Muscle cells must metabolize glucose to generate more ATP

■ The immediate source of glucose for working muscles is glycogen that is stored in muscles

Genetic endowment

The inherited physical characteristics that can affect athletic performance

●Proper nutrition is essential for optimal physical fitness and sports performance

Carbohydrate Needs in athletes

athletes engaging in 1 to 3 hours/day of moderate to high-intensity exercise should consume 6 to 10 g. of carbohydrate per kilogram

Pre-event Meals and Snacks

1 to 4 hours before competing, athletes should eat a meal that supplies 1 to 4 g of carbohydrate per kilogram of body weight High-carbohydrate, low-fat food choices

Carbohydrate loading

practice of manipulating physical activity and dietary intake of carbohydrates to increase muscle glycogen stores. A healthy person stores about 6 g of glycogen per kilogram of bodyweight

Fat Needs

Fat should supply 20 to 35% of energy for most physically active people. Athletes should focus on consuming health-promoting fats:

○ Monounsaturated fatty acids

○ Omega-3 fatty acids

Examples of foods rich in healthy fats are nuts and seeds, hummus, peanut butter, and avocado

Branched-chain amino acids (BCAAs)

Valine, Leucine, Isoleucine are amino acids with a unique branched side chain; preferentially utilized by muscle cells for energy

○ They may enhance exercise performance by delaying fatigue, sparing muscle glycogen, and decreasing protein degradation

Protein Recommendations for Athletes

Dietary intake of 1.2 to 2.0 g of protein/kg of body weight/day by athletes may be necessary.

Whey protein

is a nutrient-dense type of protein found in milk. It is nutrient dense, being rich in:

■ Essential amino acids

■ Vitamins

■ Minerals

Iron

Athletes at greater risk of iron deficiency:

● Females

● Athletes who follow low-calorie or exclusively plant-based diets

● Distance runners

Sports anemia - temporary condition that develops during the early stages of training in endurance athletes; a result of an increase in the liquid portion of blood (plasma)that results in low hemoglobin levels