Intro to Human Nutrition Midterm 2

Marasmus

protein deficiency

-lose weight but look healthy; no swelling usually do well

Kwashiorkor

protein deficiency

-Appears sick, swollen belly, often dies

-increases risk of infection

Starvation and Infection

alters the starvation response:

-lose more muscle tissue, inability to gain lean tissue

-you don't starve "well"

-combo can lead to tuberculosis, cancer, HIV

acute phase response

A response of innate immunity that occurs soon after the start of an infection and involves the synthesis of acute-phase proteins by the liver and their secretion into the blood.

-fever, fatigue, etc

-body does this on purpose

Starvation response

Response when body is deprived of calories / protein

-Very effective and complex

-loss of 40-50% of body mass is lethal

Phase 1 of the starvation response

Efficient phase

-Lots of glycogen depletion

-High rate of nitrogen loss

Phase 2 of the starvation response

Fatty acid oxidation (ketosis)

-Reduced rate of nitrogen / tissue loss at day 7

Phase 3 of the starvation response

-the body begins to break down muscle tissue (protein) for energy

-fat stores are depleted

-shift towards protein catabolism and potentially severe muscle wasting

wasting

the tendency for children to be severely underweight for their age as a result of malnutrition

starvation conclusion

the normal response is complex and effective

with infection, not effective at all, leads to death or severe issues

stunting in children

-more than 150 million worldwide

-short stature, delayed development, increased susceptibility to infections

causes of stunting

gastrointestinal infections, systemic infections, poor nutrition, bad water, chronic inflammation

muscle mass is a ______ for stunting

marker

-muscle is the biggest store of protein which is very responsive to illness, infection, etc

-muscle mass correlates to brain development

Monounsatured fats

lower LDL and VLDL

Omega 3 fatty acids

Reduce VLDL

Saturated Fats

Raise LDL and VLDL

VLDL

-High % triglycerides

-Deliver TG to liver and then turn into LDL

-Obesity, heart disease, low HDL

LDL

"Bad" highest % cholesterol

Delivers cholesterol to tissue

Atheroslerotic CVD (hardening of arteries - stroke, heart attacks)

1% increase in LDL = 2% increase in CVD

HDL

good cholesterol

High % cholesterol and protein

Moves cholesterol from tissues to liver

Carbohydrates

-Excess in Diet

-Doesn't often get converted into fat

-Gets burned before fats resulting in more stored lipids

What happens to surplus carbohydrates?

net effect of carbohydrates:

-excess CHO will get added to stored body fat, but not directly because dietary fat will be the macronutrient actually getting stored

Hierarchy of Use

Alcohol > protein > carbohydrates > fat

-Meaning one will get oxidized before another if both present in body

-Ends up storing more fat because it is the last pick

De Novo Lipogenesis (DNL)

The process by which fatty acids are synthesized from other compounds (e.g., glucose) within the liver.

Healthy diet

-Prepare food at home

-Whole, unprocessed foods

-Variety of colors / balance

-AMDR - acceptable nutrient dietary range

-Exercise regularly

fad diets

weight-loss plans that are popular for only a short time

-promise quick results

-too good to be true

-most fast weight loss is due to water weight loss (comes back)

harmful side effects of fad diets

- Heart Disease

- High Blood Pressure

- Certain Cancers

- Constipation

- Bone Loss

- Fatigue

- Nutrient Deficiencies

observational studies

Researchers carefully and systematically observe and record behavior without interfering with behavior.

cross sectional study

research that compares people of different ages at the same point in time

longitudinal study

research in which the same people are restudied and retested over a long period

Pitfalls of Observational Studies

-Lack of control over many factors

-Dietary effects are long term

-Correlation does not always mean causation

experimental studies

studies in which the independent variables are directly manipulated and the effects on the dependent variable are examined

insulin functions

facilitates uptake of glucose, stimulates formation and storage of lipids and glycogen

insulin resistance

greater-than-normal amounts of insulin are required to elicit a quantitatively normal response

Does everyone with insulin resistance get T2D?

No!

-about 2/3 don't

-the pancreas simply produces more insulin

-"compensated insulin resistance"

beta cell function

-produces insulin

-the beta cell is the driver of diabetes

-hyperglycemia requires beta cell failure

Pre-diabetes

A condition in which a person's blood glucose levels are above normal but not high enough for a diagnosis of type 2 diabetes.

A high % will become diabetic:

-gestational diabetes

-parents having T2D

-impaired glucose tolerance (140-200 mg/dl)

-impaired fasting glucose (100-126 mg/dl)

Fasting

When no food has been eaten for a while, triglycerides from adipose tissue are broken down, releasing fatty acids as an energy source

Feasting

when excess energy is consumed, it is stored as triglycerides in adipose tissue

food insecurity

a condition in which people do not have adequate access to food

Who is affected by food security most?

-Single women with children

-Black and Hispanic households

-Households in southern and midwestern states

-Households below 185% of the federal poverty line

Four pillars of food security

availability, access, utilization, stability

Food Availability

sufficient quantities of food available on a consistent basis

Food Access

having sufficient resources to obtain appropriate foods for a nutritious diet

Food Utilization

People must have access to a sufficient quantity and diversity of foods to meet their nutritional needs and must also eat and properly metabolize such food.

Food Stability

Access and availability of adequate food at all times

Supplemental Nutrition Assistance Programs (SNAP)

the largest antipoverty program, which provides recipients with a debit card for food at most grocery stores; formerly known as food stamps

What can you buy with SNAP?

Can buy: fruits and vegetable, meat and dairy, packaged foods and soda

Can't buy: alcohol and cigarettes, nonfood items, vitamins and minerals, fully cooked meals from the grocery stores

food security

A condition in which people have access to sufficient, safe, and nutritious food that meets their dietary needs for an active and healthy life.

Calorie restrictions

The practice of limiting dietary energy intake (while consuming sufficient quantities of vitamins, minerals, and other important nutrients) for the purpose of improving health and slowing down the aging process.

dietary fructose

Greatest change in diet over last 40 years, leads to:

-Increase in visceral fat

-Increased triglyceride levels

-Increased hepatic fat synthesis

-Worse insulin sensitivity

-These average about 8-10% of american diet

-Leading cause of liver disease

high fructose corn syrup

55% fructose and 45% glucose

Sucrose (table sugar)

half fructose and half glucose

NAFLD

impacts 90 million Americans- threatening epidemic of cirrhosis

-Obesity causes insulin to not work as well

-That means more insulin is released in the blood to compensate

-High insulin and glucose levels all the time cause liver lipogenesis (making and storing more fat)

-Elevated synthesis and storage of fat in liver is very common

effects of reduced sugar intake

-reduces liver fat

-reduces synthesis of fat in the liver

-reduces fasting insulin

-lowers LDL cholesterol

gestational diabetes

50% of patients progress to T2D

-Insulin resistance in all pregnancies (stress test of pancreas)

-Progesterone makes more insulin resistance

-If you don't lose weight after pregnancy, T2D

genetics of T2D

T2D is strongly hereditary:

-If both your parents have T2D, you have 90% chance

-yet we cannot find the genes responsible for it

- "missing heritability"

hyperglycemia

high blood sugar due to:

-Insulin resistance

-Insufficient insulin production

importance of beta cell exhaustion

treating early T2D improves beta cell function:

-treat through insulin sensitizing changes(weight loss)

-treating early T2D patients w insulin

-treating with exercise-allows the pancreas to rest

*all more effective early rather than late

dietary treatment of T2D

weight loss

-effectiveness is apparent within first 5 lbs of weight lost

-Effects of negative energy balance on liver glycogen stores reduced hepatic glucose production and fasting blood glucose concentrations within a few days

-Reduced glucose allows for beta cells to rest and recover

progression from insulin resistance to T2D

follows a predictable sequence through pre-diabetes:

-progressive loss of pancreatic beta cell functions

strength/power activities "resistance exercises"

duration: seconds= bursts

relates to increase in muscle mass

aerobic activities "cardio"

-Duration longer than seconds

Training induces cardiovascular adaptations(improved fitness):

-typically lean

-reduced blood TG

-higher HDL

-reduced body fat and weight

-Improved insulin mediated glucose utilization

factors that increase aerobic capacity

1) Endurance exercise training- high oxygen demand for prolonged periods

2) High altitude- Increases red blood cells

3) Increased hematocrit (e.g., erythropoetin)

4) ?PPAR delta agonists

5) Genetics

factors that increase muscle anabolism

1. Amino acids - Leucine/BCAA effects. KIC effects

2. Carbohydrates - compete with AAs for oxidation

3. Insulin- Direct and indirect effects

4. GH/IGF-1 - Effects in adults; fuel selection

5.Testosterone- "Log-linear" dose-response curve:10 x incr. dose doubles effect (implications for use and Rx)

6. Muscle stretch/tension: Resistance exercise

7. Beta-3 agonists - e.g., clenbuterol

8. Myostatin? - animal models, human data

9. Genetics - some are born lucky, some not

- Stretch, protein, hormones, genes

factors that increase muscle catabolism

1. Amino acid deficiency

2. CHO deficiency-less competition with AAs for oxidation

3. Insulin deficiency

4. Bed rest, inactivity

5. Cytokines -TNF, IL-1, IL-6, etc. (e.g., illness)

6. Glucocorticoids -Protein breakdown

7. Thyroid hormone-Dual effects

aerobic training

-30+ minutes of sustained aerobic activity

-3 times a week

-intermittent activity is not the same (Walking to work)

strength/resistance training

-70% 1 max rep times 10 times three sets for each muscle group

-Substantial gains in muscle mass and strength - variable among individuals

what do athletes eat?

-carbs: aerobic activities use up muscle so they need to be filled w carbs

-protein: while doing strength training

-CHO: strength training for body builders

- lots of supplements

consequences of PEDs

steroids

-increase in muscle mass and strength

-low HDL, roid rage, acne

blood doping

-increase oxygen carrying capacity of blood to exercising muscles

protein quality

Refers to the amino acid profile and the digestibility of a protein source.

complete protein

contains all 9 essential amino acids

incomplete protein

a protein that is missing one or more of the essential amino acids

protein complementation

combining incomplete protein sources to provide all of the essential amino acids in relatively adequate amounts

pros of vegetarianism

-lower body weight

-lower risk of T2D and obesity

-reduced risk of heart disease

-better digestive health

-environmentally friendly

cons of vegetarianism

-easy to be nutrient deficient(protein, calcium, iron, etc)

-difficult to eat in some social situations

when do we need more protein?

infants: 1.1-1.5g/kg a day

pregnancy: RDA + 25g

breastfeeding: 1.5g/kg a day

injury/illness: more to aid healing of tissues

The Liver's role in starvation

-Glycogen depletion

-reduced glucose release into blood

-lowers blood glucose, insulin levels

-increased fatty acid oxidation/ketosis

-reduced gluconeogenesis from amino acids to supply the grain

The Pancreas's role in starvation

Reduced insulin secretion

Adipose Tissue's role in starvation

Increased fatty acid release into blood

Muscles's role in starvation

-Reduced glucose oxidation

-increased fat oxidation

-reduced protein breakdown & amino acid release

The brain's role in starvation

-Keto-adaptation (can use ketones);

-reduced glucose oxidation

-dramatically reduced amino acid use from proteins for gluconeogenesis

The kidney's role in starvation

Conservation of ketones

The Endocrine organs role in starvation

Multiple adaptations

what is HGP

Hepatic (liver) glucose production (increased during fasting to increase blood glucose levels during starvation)

Effects of Long-Term fructose intake on metabolic risk factors

Increased visceral fat

Increased hepatic (liver) fat synthesis through DNL

Worse insulin sensitivity (insulin resistance)

MAFLD/MASH are both terms for what disease

Fatty liver disease (over 90 million have NAFLD)

Reduced sugar intake in obese adolescents with fatty liver disease will do what?

Significantly decrease hepatic DNL

Fasting insulin lowers (lvl of insulin after eating - high=bad, low=good)