6: Fat, CHO, H20

Question 0

In what functional way do prostaglandins differ from hormones?

Answer 0

They are not produced at a discrete site, but in many places all over the body. Target cells are always in the immediate vicinity to the site of excretion.

Question 1

What are some of the main functions of prostaglandins?

Answer 1

Regulate contraction/relaxation of smooth muscle, locally act as messenger molecules (autocrine and paracrine), inhibition of platelet aggregation.

Question 2

In what conditions are elevated levels of omega-9 seen?

Answer 2

Will be higher in cases of essential fatty acid deficiency. Normally kept low because outcompeted for the same desaturase enzymes.

Question 3

What is the recommended ratio of linoleic acid to alpha linolenic acid? Is this ratio typically seen?

Answer 3

5:1. Can be seen as higher as 30:1, tends to be higher in vegetarians. Not ideal, missing ant inflammatory properties of omega-3.

Question 4

Do the requirements for essential fatty acids change during pregnancy?

Answer 4

Slight increase in requirements due to the increase of energy requirements.

Question 5

What specific roles are EFAs important for during pregnancy?

Answer 5

Omega 6 is a growth factor and omega 3 is associated with improved brain health

Question 6

Why is growth impeded when there is an EFA deficiency?

Answer 6

Ecosanoid production insufficient, which decreases blood flow through the placenta. Leads to necrosis and infarction in the placenta.

Question 7

In subjects fully adapted to ketosis, about how much of the brains energy requirements can be met by ketoacid oxidation?

Answer 7

80%. That means only need about 22-28 g/day of glucose.

Question 8

Does carbohydrate requirement increase during pregnancy? If so why?

Answer 8

Yes. Higher metabolic rate means a higher fuel requirement, increased maternal tissue (including laying down fat deposits early in pregnancy), placental-fetal unit is obligatory glucose dependent (increase esp in later pregnancy to keep up with fetal growth).

Question 9

What percentage of the newborns brain relies on glucose oxidation? What makes up for the remaining percentage?

Answer 9

70%. Utilizes ketoacids for the remainder.

Question 10

What happens to blood glucose concentration in blood during pregnancy?

Answer 10

Goes down. Start to develop a kind of insulin resistance and tend towards ketosis.

Question 11

What is the EAR for carbs during pregnancy? RDA?

Answer 11

100 (non pregnant state) + 35 g = 135 g. RDA= 175 g/day

Question 12

What is fibre?

Answer 12

Non digestible carbohydrates and lignin that are intrinsic and intact in plants.

Question 13

What is functional fibre?

Answer 13

Isolated non digestible carbs shown to have benefit. Ex inulin, psyllium

Question 14

What strong health correlation is associated with fibre?

Answer 14

Strong negative correlation between cereal fibre intake and CVD.

Question 15

Do fibre recommendations increase during pregnancy?

Answer 15

Yes increase because of increased energy requirements (recommend 14 g fibre per 1,000 kcal)

Question 16

Is thirst well correlated with fluid needs?

Answer 16

No, more behavioral. Thirst is only well correlated with needs when there have been significant losses or changes in NA status.

Question 17

Do fluid requirements increase during pregnancy?

Answer 17

Yes. Allows core temperature to stay in healthy range, needed for metabolism of extra calories and nutrients taking in etc. many reasons.

Question 18

How was the EFA requirement established?

Answer 18

Based on highest median intakes where there was no evidence of deficiency.

Question 19

What are some potential consequences of high ketoacids?

Answer 19

Bone mineral loss, high cholesterol, increased risk of kidney stones, urinary tract deposits. Not necessarily well studied.

Question 20

What are some of the physiological effects of fibre?

Answer 20

Laxative, decreased blood glucose levels, normalization of serum cholesterol.