lecture 5

Question 1

nutrition transition in mexico

Answer 1

• 30% of adults are obese in mexico, compared to 27% in canada
• 17% of adults have T2D in mexico, compared to 10.8% in canada
• sugar-sweetened beverages are an important part of mexican culture

Question 2

soda tax in mexico

Answer 2

• in an attempt to address high obesity rates, a 10% tax was imposed on sugary beverages
• while sales fell by 8%, they rebounded once educational programs recommending decreased intake were no longer running
• the effect size was fairly small, having led to a decreas of 11-14mL of soda per capita per day

Question 2

prevalence of vitamin A deficiency

Answer 2

• most widespread and serious nutritional issue for kids
• impacts 1 in 3 kids aged 6-59M
• public health problem in >50% of countries

Question 3

who is at risk of vitamin A deficiency?

Answer 3

1. people living in poverty
2. populations in which rice provides bulk of daily diet
3. children <5
4. pregnant and lactating women

Question 3

sources of vitamin A

Answer 3

• in industrialized countries, 2/3 of dietary vitamin A comes from animal sources as preformed vitamin A
• animal sources are 70-90% bioavailable
  ie. liver, milk, eggs, fish
• in developing countries, most dietary vitamin A comes from carotenoids in plants as provitamin A
• plant sources are 5-65% bioavailable
  ie. yellow and orange fruits/veg, dark leafy greens and red palm oil

Question 3

how can you assess vitamin A status?

Answer 3

a) biochemical indicator: serum retinol
b) clinical indicator: night blindness, bitot’s spots, frequent respiratory/intestinal infections
c) dietary assessment: FFQ

Question 4

consequences of VAD: xeropthalmis

Answer 4

• night blindness, conjunctival xerosis, bitot’s spots, corneal xerosis, ulceration, necrosis/keratomalacia
• bitot’s spots are the last point at which VAD is reversible

Question 5

consequences of VAD: compromised immunity

Answer 5

• known as nutritionally acquired immunodeficiency disorder
• vitamin A maintains mucosal linings preventing pathogens from entering, so deficiency can decerase their effectiveness
• impaired immune response, increased risk of infection and death

Question 5

consequences of VAD: infection

Answer 5

predisposes individuals to severe infections including respiratory infection, diarrhea, dysentery, measles, HIV and malaria

Question 6

consequences of VAD: increased morbidity and mortality

Answer 6

in mozambique:
- 34.8% of infant deaths (6-59M) can be attributed to VAD
- VAD prevalence is 71.2% in kids 6-59M

Question 7

supplementation of vitamin A

Answer 7

• decreases risk of dying by 20-30%
• only need to be given every 4-6 months (fat-soluble)
• very cheap

Question 7

how can we address VAD?

Answer 7

a) education: both nutritonal education and overall education for women
b) increase dietary intake: promote BF, dietary diversification, promote consumption of vitamin A rich foods
c) biofortification: breeding maize can increase vitamin A content of staple foods, providing 40-50% of daily requirement
d) fortification: sugar, oil and margarine can provide 15% of dily requirement
e) supplementation
f) household food production