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