L8 - Nutrition and Health

Question 1

Explain what is meant by the term ‘nutrient’:

Answer 1

Nutrients can be split into two groups:

• macronutrients
• micronutrients

Macronutrients are energy providing foods - consumed in large amounts (g). E.g. proteins, carbs, lipids and alcohol.

Micronutrients are essential and is consumed in small amounts (mg). e.g. vitamins, essential minerals, essential FAs and essential a.a.

Question 2

Energy and Nutrient Requirements:

Answer 2

This depends on the individual - age, gender, activity levels, etc.

DRV - this provides guidelines for different groups in a population.

Question 3

What is the ideal amount needed of a nutrient?

Answer 3

The amount needed of a nutrient should be sufficient to prevent any deficiencies from being seen.

In addition, at times when no intake of food occurs, we need storage of nutrients so enough nutrients should be taken to allow storage.

Societies expect more than that.

Question 4

Dietary Reference Values (DRVs)

Answer 4

This was set up by COMA (food standards agency) and became later SACN. This determines how much we eat. AIM of DRVs is to promote nutritional well being.

What is DRVs:
This is an estimate of the required amount of energy and nutrients within groups of a healthy population.

Question 5

How is DRV obtained?

Answer 5

• intake of a nutrient is looked at in a healthy population and in group with deficiency
• the intake which is advised is the amount needed to prevent clinical deficiency

Question 6

Explain the terms:

• DRV
• EAR
• RNI
• LRNI
• Safe Levels

Answer 6

What is DRVs:
This is an estimate of the required amount of energy and nutrients within groups of a healthy population.

What is Estimated Average Requirement:
Estimate of energy requirement by different groups in a population. This satisfies 50% of the population but to the other 50%, nutrient intake at this level is too low.

What is Reference Nutrient Intake:
This is used for essential nutrients e.g. vitamins, minerals etc. 2SD + EAR. This satisifies 97.5% of population. Hence, many within group will need less.

What is Lower Reference Nutrient Intake:
This satisifies 2.5-5% of population. For most of the population, this is not adequate.

What is Safe Levels:
This is used when EAR, RNI and LRNI can’t be set due to limited data. This is the range of the amount of nutrient intake advised for there to be no deficiencies nor undesirable effects.
Below range = Deficiencies
Above range = Undesirable/toxic effects

Question 7

Vitamin C

• EAR
• RNI
• LRNI

Answer 7

EAR = 25mg
RNI = 40mg
LRNI = 10mg

Question 8

Explain how tables of nutritional composition of foods are constructed, and used, when assessing the dietary intakes of individuals and comment on their reliability:

1) How to determine nutrient intake and how are food tables constructed?
2) Is this accurate?
3) Uses?

Answer 8

How to determine nutrient intake and how are food tables constructed?
In order to identify nutrient intake, food tables can be used. This is done by taking samples of a particular food and assessing mean content of energy, protein, fat, carbs, etc.

Is this accurate?
Not really - only the amount of nutrients in a batch is checked. Not in individual samples once they’ve been packaged.

Uses:

• It tells us an estimate of the energy and nutrient intake in an individual.
• Useful for formulating diets e.g. for a diabetic diet, you would avoid carb-rich foods.

Question 9

Describe the implications of over-nutrition and under-nutrition (malnutrition is both) with respect to health:

Answer 9

Undernutrition:

• usually deficient in a specific nutrient
• common in developing countries
• but also in developed countries e.g. elderly, cancer patients, hospitalised patients, people on diets, etc.

Overnutrition:

• common problem in developed countries and is increasingly prevalent in developing countries
• Usually due to too much sugar, salt, fat and more food intake.

Question 10

BMI

units, and what are the categories

Answer 10

Body Mass Index = kg/m2

BMI of 18.5-24.9 = Normal
BMI of 25.0-29.9 = Overweight
BMI of 30.0-34.9 = Obesity Grade 1
BMI of 35.0-39.9 = Obesity Grade 2
BMI > 40.0 = Obesity Grade 3

Question 11

Obesity in the UK:

Obesity is becoming more prevalent - has tripled in the last 20 yrs.

Answer 11

1) About 2/3rds are overweight or obese
2) About 22% are obese
3) Have considerable health risk

Question 12

BMI Vs. Socioeconomic Class:

Answer 12

BMI increases as socioeconomic class decreases in developed countries as people of high status tend to have labour-intensive jobs.

In developing countries, BMI increases with socioeconomic class.

Question 13

Diet (sugar and fruit & veg consumption) Vs. Socioeconomic Class:

Answer 13

Sugar consumption increases with class.

Fruit and veg consumption decreases with class.

Question 14

Childhood Obesity:

Answer 14

This is becoming more prevalent as children eat more junk food and don’t exercise. Have high risk of developing high cholesterol and T2D.

Question 15

Consequences of Obesity:

Answer 15

1. CVD
2. Stroke
3. T2D
4. Hypertension
5. Gallstones
6. Infertility

Those who have high risk of developing gallbladder disease/ gallstones tend to be fair, forty, fat, female (4 F’s).

Question 16

Risk for CVDs:

Answer 16

1) Hypertension
2) High Cholesterol
3) Obesity
4) Inactivity
5) Smoking

Question 17

High Blood Pressure:

(Causes, average intake and max intake)

South asians:

Death rate of stroke in terms of males vs. females and what is causal of this.

Answer 17

Causes: High Salt Intake
Average intake: 9g

Max intake: 6g and we only need 1g.

South asians are more susceptible to high BP, T2D and stroke.

Death from stroke is higher in males than females - due to high salt intake.

Question 18

Recommendations of the Department of Health

Answer 18

They recommend changes in percentage of nutrients which contribute to total energy.

Fat - contribute to 30% of total energy
Saturated fats, Sucrose, Proteins - 10%
Alcohol - 5%

Question 19

How do we persuade individuals to eat a healthier diet?

Answer 19

1. Education
2. Role Models
3. Control of advertising
4. Clear labelling of food products