Diet and exercise in the management of lipid profile

Question 1

Dietary fat

- Uses of dietary fats

Answer 1

Triacylglycerol- 95% of dietary fat intake

Source of energy- too much storage = weight gain

Uses:
Source of energy for muscles.

Precursors for hormones and pro-inflammatory cytokines.

Insulatory protection for neurones and organs.

Question 2

Lipid diet and lipid profile

Answer 2

Increase in Saturated fatty acids, increase in:
TC
HDL-C
LDL-C

Dose dependant effect:
Every 1% increase SFA= @% increase in LDL-C.

Therefore:
Emphasis on reducing SFA intake.

Question 3

Method of decreasing SFA consumption

Answer 3

Reduce visible fat intake

Reduce consumption of animal meat and products.

Increase consumption in vegetable products, seafood, nuts, seeds = increase in MUFA and PUFA.

Question 4

Omega 6 PUFA

• Where it is found
• Examples

Answer 4

Most common PUFA in western diet.

Found in: Vegetable oils

Example: Linoleic acid, decreases LDL-C

Reducing SFA involves replacing it with increased consumption of vegetable oils.

Question 5

Omega 3 PUFA

• Examples
• Benefits

Answer 5

Associated with improvement in cholesterol, TG and vascular function.

Examples:
Alpha linolenic acid (ALA)
Eicosapentaenoic acid (EPA)
Docosahexaenoic acid (DHA)

Question 6

Sources of Omega 3 PUFA

Answer 6

Oily fish- increase EPA and DHA

ALA- flax seeds, nuts

Question 7

Trans fatty acids (TFA)

Answer 7

Formed from the hydrogenation of PUFA oils

Behaves like saturated acids.

Increases LDL-C and fasting TG, decreases HDL-C.

Therefore decreasing tFA= healthier. Done by reducing processed food consumption.

Question 8

Dietary cholesterol

Answer 8

Only a small amount impacts TC and LDL-C

But individual response to dietary cholesterol is related to SFA response

Reducing cholesterol and SFA intake= healthier. Consume less animal products.

Question 9

Mono/Disaccharides

Answer 9

Glucose

Fructose

Lactose

Sucrose

Question 10

Non-starch polysaccharides

Answer 10

Important for GI tract function and well being

Examples:
Pectin
Cellulose

Question 11

Effect of Carbs on lipid profile

Answer 11

Increased carbs increases VLDL and reduces HDL-C.

Increase in carbs but decrease in fat increases small dense LDL but decreases total LDL.
- Smaller LDL more atherogenic.

Decreased insulin response due to continuous stimulation of high dietary carbs- increased lipolysis

Increased delivery of fatty acids and hepatic esterification.
- Overproduction of VLDL, esp VLDL1

Question 12

Monitoring carb intake

Answer 12

Carbs should not be more than 65% of energy intake

• 11% should be sugar
• 18g/ day of fibre

Fruit and veg at least 5 a day

Question 13

Fruit and veg

Answer 13

Diet high in fruit and veg= less risk of CVD

Soluble fibre in plants:
Lowers serum cholesterol- inhibits cholesterol absorption in GI

Improves antioxidant status:
Increase total antioxidant capacity
Increase glutathione peroxidase activity

Question 14

Obesity

Answer 14

XS energy intake> energy expenditure

Fat tissue is source of free fatty acids- abdominal adipose tissue is less stable.

Visceral adipose tissue is less responsive to insulin and deliver FFA via portal circulation to liver,

Question 15

Visceral obesity

Answer 15

High lipolytic activity in the visceral fat= increased FFA load to liver.

FFA converted to TG- stored in cytosol

Increases TG-rich VLDL
- Cholesteryl ester transfer protein and hepatic lipase causes these VLDL to be more dense

Denser VLDL are very atherogenic and easily transform into oxidised LDL

Question 16

Exercise and physical activity

Answer 16

Improvement in psychological and physiological state.

Exercise= increase in lipoprotein lipase activity in skeletal muscle
- Clears TG

Decreases hepatic VLDL synthesis, TC, TG and LDL-C

150 mins of moderate intensity activity.

Question 17

DASH diet

Answer 17

Dietary approaches to stopping hypertension

Rich in fruit, veg, low in fat, high in polyunsaturated.

Following this diet for 8 weeks decreases:
BP
TC
LDL-C
Increased HDL-C

Question 18

PREDIMED trial

Answer 18

Reduced ambulatory BP

Reduced fasting blood glucose

Reduced TC

Question 19

STRIDE1

Answer 19

Risk reduction intervention through defined exercise in those with high risk of developing CVD.

Effects:
Reduced LDL-C number
Increased LDL-C size
Increased HDl-C number
Increased HDL-C size