Diet and Exercise Flashcards
Diet
Dietary Fat
Triacylglycerol
Cholesterol
Dietary carbohydrate Simple sugars Polysaccharides Non starch polysaccharides Fruits and vegetables
Dietary Fat
Triacylglycerol makes up 95 % of dietary intake
Fat is energy dense - source of energy
Fat is circulated in blood as lipoproteins– arterial disease
Source of energy for muscle
Precursor for synthesis of hormones and pro inflammatory cytokines
Insulator for cell function (neurons) and organ protection
Saturate Fatty Acids (SFA)
Consumption of Saturate Fatty Acids (SFA) increases tricylglycerol (TC), HDL-C,and LDL-C even at low levels.
Dose dependent effect - for every 1% increase in SFA, serum LDL-C increases by about 2%
O-6 PUFA
Vegetable oil - margarine/spreads referred to as containing PUFA
Omega 6 PUFA, Linoleic acid (LA) decreases LDL-CH
Primary emphasis is on a diet to reduce SFA but increase consumption vegetable oils (Omega 6) to replace SFA
Consider total fatty acid consumption
O-3 PUFA
Omega 3 PUFA are associated with improvements in cholesterol, TG and vascular function
Omega 3 PUFA include alpha linolenic acid (ALA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)
Primary emphasis is a diet to improve EPA/DHA levels
Increase consumption of Oily fish to increase supply of EPA and DHA
Flax seeds, nuts provides alpha-linolenic acid (ALA) as a precursor of EPA and DHA
Trans Fatty Acids
Trans fatty acids (tFA) are formed by hydrogenating PUFA oils to stabilise them and to form a solid at room temperature
tFA increases LDL-C, decreases HDL-C, and increases fasting TG
Primary emphasis is a diet to decrease tFA consumption
Reduce consumption of processed food
Diet and Carbohydrates
Reduction in dietary intake of fat is frequently associated with increased intake of carbohydrates (CHO) ? Is there a reduction in total energy intake
CHO can enhance hepatic synthesis of VLDL and reduce HDL creating an adverse lipid profile
Low fat with increased CHO can lead to a reduction in total LDL but increase in small dense LDL which are more atherogenic.
A down regulation of insulin response due to continued stimulation from higher dietary CHO leads to increased lipolysis
This increases a greater delivery of fatty acids and an increase in hepatic esterification and subsequent over production of VLDL, particularly TG- rich VLDL1
Impact of carbohydrates
Dietary intakes of CHO should account for no more than 65% of energy requirement
The consumption of added sugar should be no more than 11% of food energy
Fibre consumption should on average of 18g per day – Non starch polysaccharide (NSP)
Primary emphasis is on a diet to moderate CHO intake
Reduce sugar intake
Increase fruit and vegetable intake to at least 5 portions per day,
To monitor total energy intake
Fruits & veg
Diets higher in vegetables and fruits are commonly associated with a reduction in CVD risk
Soluble fibre in plants had been shown to decrease serum cholesterol, through inhibiting cholesterol reabsorption in GI tract
Consumption of F&V improved antioxidant status by improving plasma total antixoxidant capacity and glutathione peroxidase activity in healthy young adults
Primary emphasis is a diet to improve lipid profile
Increase low calorie fruit and vegetable intake to at least 5 portions each day
Visceral Obesity
High lipolytic activity of the visceral fat contributes to deliver an increased load of
FFA to the liver
FFA are then converted to TG and stored in the cytosol
This in turn, contributes to form very low-density lipoprotein (VLDL) particles enriched with triglycerides.
Through cholesteryl ester transfer protein (CETP) and hepatic lipase activity, triglyceride enriched low-density lipoprotein (LDL) become smaller and denser particles
These small LDL particles are highly atherogenic and have been found to be easily transformed into oxidized-LDL
DASH
Rich in fruit, vegetables and low-fat dairy, and with a higher ratio of polyunsaturated fat to saturated fat than the other diets
The researchers found that, compared with the control diet, following the DASH diet for eight weeks:
lowered blood pressure
lowered total cholesterol
lowered LDL (“bad” cholesterol)
lowered HDL (“good” cholesterol)
PREDIMED trial
Reduced ambulatory BP
Reduced fasting blood glucose
Reduced total cholesterol
Exercise
Independent of diet exercise Reduced LDL cholesterol particle number Increase LDL cholesterol size Increase in HDL cholesterol particle number Increase in HDL cholesetrol size
