CARBOHYDRATE COUNTING
– BASICS & BEYOND
Francesca Annan RD
Carb counting basics
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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?
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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
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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.......
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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
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Composition of Foods
This is where dietitians get
information .
Basis of information in
books like Carbs&Cals or
calorie counters
Resources
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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?
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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??
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Useful for?
RICE
 PASTA
 CEREALS
 OVEN CHIPS
 POTATOES
(mash/boiled/baked)
 RECIPES
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Step 1: Weigh your carbohydrate food
Consider using digital scales accuracy
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
Step 2: Look at the food label
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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 food
Amount of carbohydrate on the label divided by
100
Multiply this number by the weight of your food
This 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 cereal
Typical 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 + water = cooked pasta
Dry pasta 75g
Cook exactly as stated on
the instructions
75g dried pasta gives
cooked pasta 170g
Uncooked to cooked weight more than doubles
water
Pasta Food Label
A 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 + Water = cooked rice
Rice (uncooked) 40g
Cooked following
instructions
Cooked rice 100g
Uncooked to cooked = increases in weight 2.5 times
water
Rice Food Label
A 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&Cals
Information from nutritional composition tables
Or 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 too
Does this matter?
What happens when you have baked potatoes?
Experience counts!
Use the following table as a useful tool
Baked potato
Per 100g
Kcal
Protein CARB
Baked, flesh 136
& skin
3.9
32
Baked, flesh 77
only
Boiled
72
2.2
18
1.8
17
Mashed
1.8
16
104
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!
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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??
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When eating the WHOLE
serving size or suggested
portion size
Useful for snacks and
packaged foods
E.g.
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Cereal bar
Chocolate Bar
Crisps
Yoghurt
Sliced bread
How?
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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 = 0.08g
125g will contain 0.08 x 125 =
10g
its not just amount of carbohydrate
that matters!
Fat, protein, GI and glycaemic load
What are the challenges?
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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
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Regardless of GI pre
meal insulin more
effective
How many foods are pure
carbohydrate?
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Cooked pasta
30g carbohydrate
5g protein
1g fat
Meals are mixed
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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
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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
Food
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Amount of
carbohydrate
Fat & protein
GI/GL
Plus
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Last insulin bolus
Activity
Blood glucose levels
Calculating insulin doses for food
Manual calculation
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Maths
Ratios per g carb
Or units per 10g carb
Can you calculate
active insulin
Duration of action
Automated calculations
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Bolus advisors on BG
meters, insulin pumps
Diabetes Apps
 InsulinCalc
 Insulin
Pro