Human Nutrition - Option D1 Flashcards
Distinguish between essential and non-essential nutrients
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
Outline how to determine the energy content of food
-Combust (burn) 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
-Formula: Mass of water (g) x 4.2 (J/g℃) x Temp increase (℃)
What must be known/ kept constant in calorimetry
-mass of food sample
-mass/ volume of water (1g = 1ml)
-starting temperature of water
-distance between calorimeter and burning food sample
–Note that error is often caused by heat loss to environment
and/ or incomplete combustion of food sample
Vitamin D Deficiency
-Lack of vitamin D or calcium can affect bone mineralization and cause rickets or osteomalacia
-Rickets: in children when the bones near the growth plates do not mineralize properly, irregular bone growth, bowed legs
-Osteomalacia: Bone plates in adults are fully formed, “soft bones”(painful/ weak bones, difficulty walking, increased fractures)
Vitamin C Deficiency
Failure to ingest adequate amounts of Vitamin C results in scurvy (and weakened immune system function)
Apetite Control Center
-Hypothalamus
-Hormones produced by the stomach, intestines, pancreas, and adipose tissue act on the hypothalamus
-Hormones either stimulate the hypothalamus to promote feeling hungry or inhibit the hypothalamus to promote feeling full
Malnutrition
-is a health condition that is caused by a deficiency, imbalance, or excess nutrients in the diet
-Caused by improper intake of nutrients (too much = overnutrition, too little = undernutrition) which can be caused by social/ socioeconomic factors
-Caused by improper utilization of nutrients by body (illness/ disease/ malfunction in hypothalamus)
Health Consequences of Obesity
-(overweight) is common in overnutrition (leading to CHD/ diabetes etc.)
Health consequences of starvation and anorexia
-are common in undernutrition (leading to breakdown of body tissues/ organ failure)
-In severe cases, body breaks down heart muscle (which can lead to death).
High Cholesterol Leading to CHD
-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
