Human Nutrition Flashcards
Essential Nutrients
Cannot be replaced or synthesized by the body, so must be ingested in the diet
Non-essential Nutrients
Can be synthesized by the body or have a replacement nutrient which serves same dietary purpose, so are not necessary in the diet
CALORIMETER
By combusting (burning) a known mass of a food sample, the energy content of the food can be calculated by measuring the heat energy released from the burning food using a CALORIMETER.
Heat from the burning food is transferred to the water and the temperature increase of the water is used to calculate the energy content of the food sample
Vitamin D dietary sources
fish oils, egg yolk, enriched dairy products
Lack of vitamin D
Lack of vitamin D or calcium can affect bone mineralization and cause rickets or osteomalacia
Rickets
Develops in children when the bones near the
growth plates do not mineralize properly
Leads to irregular, thick & wide bone growth
(decreased height/ bowed legs)
Osteomalacia
Bone plates in adults are fully formed so
you cannot develop rickets but you may develop a similar
condition called osteomalacia = “soft bones”(painful/ weak bones, difficulty
walking, increased fractures)
Vitamin D
Vitamin D can be synthesized as well by exposure to sunlight
hypothalamus
appetite control center of the brain
Malnutrition
Malnutrition is a health condition that is caused by a deficiency, imbalance, or excess nutrients in the diet
Health consequences of Obesity (hypertension)
Hypertension (abnormally HIGH blood pressure)
More weight = more strain on heart to pump blood (faster heart rate and increased blood pressure)
Systolic (heart contracting)/ diastolic (heart relaxing) = usually 120/80 (mmHg);
Hypertension = pressure
values consistently above 120/80
Higher cholesterol = deposits in arteries/ narrowing blood vessels
(atherosclerosis) = higher blood pressure
Health Consequences of Obesity (Type 2 Diabetes)
Type II Diabetes (non-insulin dependent = decreased sensitivity to insulin = hyperglycemia = high blood sugar levels)
Fat, liver, and muscle cells become desensitized to insulin (no longer respond to it) - due to excessive overstimulation by insulin due to diets rich in sugars (note that insulin is released by the pancreas and it triggers cells to take in glucose from the blood in order to LOWER your blood sugar)
Overweight individuals who have high sugar diets more likely to develop type II diabetes.
Starvation
Starvation: severe restriction (deficiency) of daily energy intake
Body will begin to break down OWN tissue as not receiving enough energy from diet (adipose (fat) tissue broken down first as fats contain more energy and their breakdown does not (usually) disrupt homeostasis/ metabolism - after adipose tissue broken down, muscle tissue broken down to provide proteins)
IF enough bodily tissue is broken down, organs can become severely damaged and this can lead to death.
Anorexia Nervousa
Anorexia nervosa: eating disorder where individuals severely limit food intake
In severe cases, body breaks down heart muscle (which can lead to death). As heart muscle atrophies and weakens, blood flow is reduced and blood pressure drops. Heart may also develop arrhythmias (irregular rhythms/ beats) due to electrolyte
imbalances.
Cholesterol
Fats and cholesterol are non-polar/ hydrophobic (difficult to transport in blood)so they are “packaged” with proteins to form transport structures called lipoproteins
Two Types of Cholesterol
- LDL (low density lipoproteins) - carry cholesterol FROM the liver TO the body (increase blood cholesterol levels)
- HDL (high density lipoproteins) - carry cholesterol FROM the body TO the liver (for disposal - decreasing blood cholesterol levels)
The effect of fats on Cholesterol
The TYPE (and amount) of fat (fatty acids) a person eats every day affects the amount of cholesterol in the blood:
Saturated fats: ↑LDL levels = ↑BLOOD CHOLESTEROL
Trans fats: ↑LDL levels and ↓HDL levels = SIGNIFICANTLY ↑BLOOD CHOLESTEROL
Cis-polyunsaturated fats: ↑HDL levels = ↓BLOOD CHOLESTEROL levels
Atherosclerosis
Atherosclerosis: build-up of plaque deposits
(fats, cholesterol, cell debris etc.) in arteries - When
LDL levels are high, LDL particles form deposits in
artery walls
Effect of High Blood Pressure
As fat/ plaque deposits build up in arteries, they restrict blood flow, narrowing the lumen (stenosis), reducing elasticity of the arterial wall (more prone to rupture b/c cannot stretch as well under pressure)and increasing blood pressure
This causes chronic inflammation (swelling) and damages arterial (endothelial) wall
Chronic inflammation leads to more lipid, cell debris, calcium and cholesterol accumulation (rough/ hardened walls)
