Carb Counting 101: How to Guess the Carbs like a Pro
Whether you’re wrangling a toddler who has just hidden half their toast under the sofa, negotiating snacks with a moody tween, or you’re a teen with Type 1 Diabetes learning to take charge of your own meals- carb counting is a superpower worth having. Think of it as a secret skill that helps keep blood sugars steady, energy levels up, and makes life with Type 1 just a little smoother.
The great news? You don’t need to be a maths genius to master it. With a few tricks and a little practice, you’ll be able to look at almost any plate of food and make a pretty good carb estimate- like a pro.
Why Carb Counting Matters
Carbohydrates are the body’s main source of energy. When you eat carbs, your body breaks them down into glucose, which then enters the bloodstream. For people with Type 1 Diabetes, knowing how many carbs are in a meal is key to matching them with the right amount of insulin.
Getting carb counts right helps:
Keep blood glucose levels more stable
Prevent highs and lows
Give you more flexibility in food choices
Reduce some of the mealtime stress for everyone
1. Different Ways to Count Carbs
There isn’t just one way to count carbs- you’ve got a whole toolkit to choose from:
Food labels
Look for the “Carbohydrate (of which sugars)” line
Be careful- UK labels often show carbs per 100g and per portion. If your portion is bigger or smaller than what’s listed, you’ll need to adjust. (E.g. if a flapjack is 80g but the label shows carbs per 100g, you’ll calculate 80% of that number)
Carb Counting Apps
Handy when you’re out and about. Many have UK restaurant and supermarket databases, plus barcode scanners.
Find our list of the best carb counting apps here: https://www.t1dwaverider.co.uk/tech-reviews-diabetes-tools/appetite-for-success-the-best-t1d-carb-counting-apps
Recipes at Home
When cooking, add up the carbs from each ingredient, then divide by the number of portions
Example: a Shepherd’s Pie with 1kg potatoes (=200g carbs), carrots (=20g carbs), onions (=15g carbs) and mince (=0g carbs) = about 235g carbs total. If it serves 5, each portion has roughly 47g carbs.
Cafes, Restaurants, and Shops
Many UK chains (think Pret, Greggs, Costa, McDonald’s, Wagamama) list nutrition online or in-store
Supermarkets often provide carb values for bakery items like doughnuts, sausage rolls or croissants
A quick search before or while you’re in the queue can save stress later
2. Know Your “Carb Heroes”
Not all foods are carb-packed. Protein (chicken, eggs, cheese) and most veggies (like broccoli, cucumber, spinach) are low-carb or almost carb-free. The real carb heroes- the ones you’ll need to count, include:
Grains: bread pasta, rice, cereal
Starchy veg: potatoes, parsnips, sweetcorn, peas
Fruit: bananas, apples, berries, grapes
Dairy: milk, yoghurt (especially sweetened ones)
Snacks & treats: crisps, biscuits, cake, chocolate bars
3. Fast, Medium and Slow Carbs
Carbs don’t all act the same in the body. Knowing the difference helps you plan better:
Fast-acting carbs: raise blood sugar quickly (handy for treating hypos). Examples: glucose tabs, jelly babies, fruit juice, Lucozade, honey.
Medium-acting carbs: raise blood sugar steadily, giving moderate energy. Examples: porridge oats, bananas, granola bars, milk.
Slow-acting carbs: digest slowly, giving longer-lasting energy (but can cause later spikes). Examples: wholemeal bread, pasta, lentils, beans, pizza.
4. The “Handy” Portion Trick
Your hands are always with you. Use them as a quick guide:
Fist= about 1 cup (think pasta, rice, fruit salad)
Palm= about 90g cooked meat or fish (not much carb, but good to know)
Handful= small snacks (like crisps or popcorn)
Thumb= about 1 Tbsp (like peanut butter or jam)
5. Remember the Magic Numbers
It helps to keep rough “cheat codes” in your head or written down somewhere easily accessible:
1 slice of bread @ 15g carbs
1 small apple or satsuma @ 15g carbs
200ml glass of milk @ 10g carbs
1 medium potato @ 30g carbs
6. Don’t Fear Food Labels
The label is your best friend. Remember to:
Check the portion size- is that the whole packet or just half?
Look at total carbs, not just sugar.
Fibre can sometimes be subtracted (ask your diabetes team if this applies to you).
Pro Tip: if your crisps packet says 25g carbs per portion, but you eat two portions…that’s 50g carbs.
7. Practice Makes Perfect (Even With Pizza)
Meals like pizza, curry with naan, or ice cream can be sneaky. They sometimes cause two blood sugar rises: one soon after eating, and another hours later. That’s because fat and protein slow down digestion.
Don’t stress if your carb guesses aren’t spot on- over time, you’ll learn how your body reacts. Parents- keeping a food diary for a while can help spot patterns.
8. Make It a Game for Younger Children
Even toddlers can start learning:
Guess the carbs in a food, then check with a carb counting app or label.
Use play food or cooking time as practice- “How many carbs do you think are in this potato?”
Celebrate close guesses- it builds confidence and makes it fun.
9. Keep Tech on Your Side
Apps, insulin pumps and continuous glucose monitors (CGMs) can make carb counting much easier. Some UK-friendly apps even have supermarket and restaurant databases, plus barcode scanners. But even without tech, your brain, a notebook and maybe a quick Google search are powerful tools.
Final Thought: Progress, Not Perfection
Carb counting isn’t about being 100% perfect- it’s about building skills, confidence, and making food feel less stressful. With practice, you’ll be able to look at a plate and think, “That’s about 45g carbs”…and be close enough to keep blood sugars steady.
So whether you’re a parent guiding your toddler, a child learning the ropes, or a teen taking on more independence- remember: carb counting is a superpower that puts you in control. And like any superhero skill, the more you practise, the stronger it gets.
