glycemic load/glycemic index

main organs that utilize glucose

-brain -liver -adipose tissue -muscle -availability of glucose to these tissues is determined by hormones, the nervous system, availability of circulating substrates

comparing GI and GL

GI=doesn't consider quantity of carb-containg food ingested GL=consider quantity/quality of carb-containing food as well as number of meals eaten per day (dietary glycemic load)

stages of insulin resistance

high glycemic load----(+)increased insulin demand----(+)beta cell exhaustion----(+)glucose intolerance----(+)diabetes high GL---(+)counterregulatory hormones---(+)increased post-prandial free fatty acids---(+)increased insulin resistance---(+)glucose intolerance---(+)diabetes

glucose intolerance

pre-diabetes stage of hyperglycemia associated with insulin resistance and increased CHD risk

glycemic load

-calculated by multiplying (glycemic index)*(carbs/gram in a food)/100 -takes into account the AMOUNT of food being consumed; consuming even a low GI food in large quantities can greatly increase blood glucose -scientific community thinks it is more useful than GI -the higher the GL, the greater the expected raise in blood glucose and thus the insulinogenic effect of the food -long term consumption of diet consisting of high GL foods assoc. with increase risk for type 2 diabetes and CVD/CHD -dietary glycemic load = sum of all glycemic loads consumed in a day

overview

-classification of dietary carbs based on their ease of absorption and effect on the elevation of blood glucose -research suggests that glycemic index and load offer a way to examine the relative risks of diets designed to prevent coronary heart disease and obesity

insulin resistance

-condition where cells fail to respond normally to the actions of insulin -leads to increased blood glucose levels; body tissues are not taking up enough glucose

link between GL/GI and health problems

-has been shown that the longer and higher the elevation in blood glucose, the greater the risk for developing chronic diseases and obesity long term=T2D, CHD short term=insulin resistance -patients with type 2 diabetes will improve glycemic control b adapting to low GI diet

glycemic index

-measures how a carb-containing food raises blood glucose -was created in order to assign a numerical value to the effect of food of blood glucose -provides quantitative comparison between foods -definition; the increase in blood glucose level above the baseline during a 2-hour period following the consumption of a defined amount of carbohydrate (usually 50g) compared with the same amount of carb in a reference food -measured by recording the blood glucose level 2 hrs after food ingestion -glucose is arbitrarily assigned a value of 100, commonl used reference food -discrepancies can be caused if different reference foods are used (i.e. white bread) -GI can vary greatly for foods that are very similar depending on the ingredients used, the temperature of the food, other factors

what determines blood glucose at any given moment

-rate of glucose absorption -rate of tissue uptake (regulated by muscle and adipose tissue/GLUT4/need of other organs like the brain) -rate of gluconeogenesis in the liver

importance of dietary carbs

-the body, at an given moment, contains only a few grams of carbs; thus, obtaining glucose in the diet and the livers role in gluconeogenesis/glycogenolysis are very important for maintaining a healthy level of glucose

glycemic response

-the effect that carb-containing foods have on blood glucose levels -varies with time digestion/absorption take to occur for that food -some foods cause a rapid rise in blood glucose, others are more gradual

factors that cause variations in GI/GL

-variable amount of carbs is same type of food -composition of meal -previous meal consumption -physical activity -reference food used -glucose tolerance of subjects