carbohydrate counting – basics & beyond francesca annan rd
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CARBOHYDRATE COUNTING – BASICS & BEYOND
Francesca Annan RD
Carb counting basics
Most of the glucose in the blood comes from digestion of carbohydrate foods.
Excess glucose is stored as glycogen in muscles and liver
Stored as adipose tissue – fat Fat and protein are not converted
directly to glucose.........
What else influences BG after eating?
Previous activity levels Previous insulin bolus & Duration Insulin
Action Adequacy of basal/background insulin Meal composition and GI Environment Other physical factors
Carbohydrate counting – what should it involve
Estimation or calculation amount of carbohydrate in food
Calculation of an insulin dose based on amount of carbohydrate, blood glucose levels, activity
Not just about carbohydrate in food
Start with.......
Accuracy of information and experience! Food labels are not always accurate The same food from a different food
producer may not have the same nutritional composition
If you compare information from different sources you will get different information
Nutritional information
Composition of Foods
This is where dietitians get information .Basis of information in books like Carbs&Cals or calorie counters
Resources
Books – Carbs & Cals, food pictures, calorie counters,
Apps – pictures and nutritional information
Websites – for restaurant/fast food info, supermarkets to access food labels and find info about foods
How accurate do you need to be?
Within 10g Within 5g Within 1g
How accurate an insulin dose can you deliver?Nearest 0.1 unit, 0.5unit or 1 unit?
WORKING OUT CARBOHYDRATE USING WEIGHING SCALES
When to Use??
Useful for?
RICE PASTA CEREALS OVEN CHIPS POTATOES
(mash/boiled/baked) RECIPES
Step 1: Weigh your carbohydrate food
Remember to zero the scales or turn on after putting plate/bowl on the scales.
Put your normal portion of food e.g. pasta/rice/cereal onto plate/bowl
Consider using digital scales accuracy
Step 2: Look at the food label
Find TOTAL CARBOHYDRATE on the food label
Use per 100g
column unless you are having the average portion size or the whole serving
Make the maths as easy as possible!
Use the amount of carbohydrate per 100g to work out how much is in 1g of the foodAmount of carbohydrate on the label divided by 100 Multiply this number by the weight of your foodThis gives you the amount of carbohydrate in your portion
Example: Breakfast cereal
Your portion of cereal weighs 60g
The label tells you that 100g cereal contains 88g carbohydrate
If 100g of the cereal contains 88g carbohydrate then 1g will contain (88 ÷ 100 ) 0.88g.
Your portion will contain (0.88g x 60g) 53g carbohydrate
Example: Breakfast cerealTypical values Typical
value per 100g
30g with 125ml milk
Energy 326 kcal 157kcal
Protein 310g 7g
Carbohydrate 88g 28g
Of which sugars
22g 13g
Of which starch 45g 13g
100g portion
serving
Dried wieghts versus cooked weights
Foods like pasta, rice and baked potatoes absorb or lose water through cooking.This changes the nutritional composition
Pasta
Dry pasta 75g
water
Cook exactly as stated on the instructions
75g dried pasta gives cooked pasta 170g
Dry pasta + water = cooked pasta
Uncooked to cooked weight more than doubles
Pasta Food LabelA 75g serving once cooked weighs 170g
Typical values Per 100g (dry weight) Per 75g serving(dry weight)
Energy 346 kcal 262 kcal
Protein 12g 9g
Carbohydrate 70g 63g
Of which sugars 4g 3.6g
Of which starches 66g 59.4g
Rice
Rice (uncooked) 40g
water
Cooked following instructions Cooked rice 100g
Rice + Water = cooked rice
Uncooked to cooked = increases in weight 2.5 times
Rice Food LabelA 40g serving once cooked weighs 100g
Typical values Per 100g (dry weight) Per 40g serving (dry weight)
Energy 316 kcal 126 kcal
Protein 7.0g 2.8g
Total Carbohydrate 75.0g 30g
Of which sugars 0.2g 0.1g
Of which starch 69.8g 27.9g
Using labels for rice and pasta
difficult?Cooking for one you could weigh out dried pasta before cooking, (if you cook exactly as it says on the label?)Use information about cooked pasta and rice examples Carbs&CalsInformation from nutritional composition tablesOr use the food label to work out how much 1g cooked rice or pasta will contain and then calculate your portion size from its’ weight.
Potatoes
Baked potato – remember that carbohydrate value increases if skin is eaten tooDoes this matter?What happens when you have baked potatoes?Experience counts!Use the following table as a useful tool
Baked potatoPer 100g Kcal Protein CARB
Baked, flesh & skin
136 3.9 32
Baked, flesh only
77 2.2 18
Boiled 72 1.8 17
Mashed 104 1.8 16
Baked potato
Could you use the weight of the uncooked potato?
Compare the uncooked and cooked potatoes & the carb values
What do you think?
If you use carbs &cals the values in the book are based on flesh only.
Handy Measures – literally!
Very useful tool, you can use your hand as a guide to portion sizes.
Once portion sizes have been weighed, look at portion in a bowl/cup/measuring spoon of product
So you don’t have to re-weigh every time – use these handy measures
HOW TO WORK OUT CARBOHYDRATE USING FOOD LABELS
When To Use?? When eating the
WHOLE serving size or suggested portion size
Useful for snacks and packaged foods
E.g. Cereal bar Chocolate Bar Crisps Yoghurt Sliced bread
How? Look at TOTAL CARBOHYDRATE PER SERVING/PORTION
different portion size?Look at TOTAL CARBOHYDRATE
Read label per 100g
Weigh your portion size e.g. 125g
Work out how much carbohydrate there will be in 1g
Use this to calculate the amount of carbohydrate in your portion
100g contains 8g carbohydrate so 1g contains 8 ÷ 100 = 0.08g125g will contain 0.08 x 125 = 10g
Fat, protein, GI and glycaemic load
its not just amount of carbohydrate that matters!
What are the challenges?
Amount of carbohydrate predicts 66% glucose response
Glycaemic load predicts 88% glycaemic response
Fat & protein content of foods alter digestion and absorption and therefore blood glucose response
GI
GI
Regardless of GI pre meal insulin more effective
How many foods are pure carbohydrate?
Cooked pasta 30g carbohydrate 5g protein 1g fat
Meals are mixed
The amount of protein and fat in a meal will alter the blood glucose response
But we need more research and practical studies to produce better practical guidelines
What do we know
Data to be published from a study in Australia demonstrates that high protein and fat meals have prolonged raised post meal glucose curve
But insulin requirements are not as high as previously published by European
Work on food insulin index in non diabetics shows that protein and fat ingestion does not stimulate pancreatic insulin production
Calculating insulin doses for food
Amount of carbohydrate
Fat & protein GI/GL
Last insulin bolus Activity Blood glucose
levels
Food Plus
Calculating insulin doses for food
Maths Ratios per g carb Or units per 10g
carb Can you calculate
active insulin Duration of action
Bolus advisors on BG meters, insulin pumps
Diabetes Apps InsulinCalc Insulin Pro
Manual calculation Automated calculations