Diabetes diet: carbs, glycemic index and a plate that keeps blood sugar in check
In diabetes, the question "what can I eat" is the wrong one. You can eat almost anything — what matters is how much, in what company and how fast a given meal raises your glucose. Here, diet is the strongest lever you have: in prediabetes and type 2 diabetes it can reverse the process, and in any diabetes it genuinely reduces swings and HbA1c. This guide lays out the principles that work — without a list of "forbidden foods" on the fridge.
Important: this article is informational and does not replace advice from your doctor or diabetologist. Insulin and medication doses, glucose targets and any changes to treatment are set with your doctor alone — especially if you take insulin or medicines that can cause hypoglycaemia (e.g. sulfonylureas). Ranges and targets vary between people; the ones in this text are approximate.
There is no single "diabetes diet" — the principles matter, not the name
You don't have to choose between "keto", "Mediterranean" and "low-carb". The research agrees on one thing here: there is no single winning scheme — the one that works is the one that keeps your glucose lower and more stable, supplies enough protein and fibre, and that you can keep up for months. The rest is detail tailored to you. The principles below are the common denominator of every good approach.
Carbs: not zero, but controlling quantity and quality
Carbs are what raise glucose the most — but "zero carbs" is neither the goal nor realistic for most people. The goal is less, better quality and counted:
Quantity. The biggest difference comes from cutting the "fast" sources: sweets, white bread, sugary drinks, juices. Exactly how much is individual; many people with type 2 diabetes do well on a moderate restriction (not starvation), agreed with a doctor or dietitian.
Quality. Swap refined sources for ones with fibre that digest more slowly: whole grains instead of white, legumes, vegetables, coarsely ground groats. The same "gram of carbs" from lentils and from a bread roll affects glucose in completely different ways.
Glycemic index (GI) vs glycemic load (GL)
GI tells you how fast a food raises glucose — but divorced from portion size it can mislead. Watermelon has a high GI, yet a real portion holds few carbs. That's why glycemic load is more practical: it combines quality (GI) with quantity (grams of carbs per portion):
| Reach for more often (low GL) | Limit / watch the portion (high GL) |
|---|---|
| legumes (lentils, chickpeas, beans), non-starchy vegetables | sugary drinks and juices, sweets, honey, syrups |
| whole grains: oats, buckwheat, wholegrain sourdough bread | white bread, white rice, thin pasta, instant cereals |
| berries, apple, pear — whole, not as juice | potatoes (especially mash), overcooked rice, ripe bananas in a large portion |
A simple trick that lowers GL without giving anything up: cooling potatoes, rice or pasta (resistant starch) and al dente instead of overcooked soften the glucose spike.
Full explanation with a food table: glycemic index and glycemic load.
Carbohydrate exchanges: when you really do need to count
1 carbohydrate exchange = 10 g of digestible carbs (that is, total carbs minus fibre). Counting exchanges is crucial if you take mealtime insulin — the dose depends on the number of exchanges (your doctor sets the ratio). With type 2 diabetes and no insulin you don't have to count to the gram, but a sense of "how many carbs I'm eating" is still the single best habit — because it shows where the excess quietly creeps in.
The catch is that counting from tables is tedious, which is why people quickly give it up (how to count exchanges step by step, with a table: carbohydrate exchanges). This is exactly the kind of thing an app can most easily take off your plate — more on that below.
A meal's makeup and order flatten the spike
The same plate eaten differently gives a different glucose curve:
Never carbs on their own. Add protein (egg, fish, poultry, quark, legumes), a healthy fat (olive oil, nuts, avocado) and fibre (vegetables) — this slows digestion and cuts the spike.
Order matters. Eating vegetables and protein before the carbs can noticeably lower post-meal glucose — one of the cheapest tricks you have.
Ditch liquid calories. Juices and sugary drinks are the fastest route to high spikes and the easiest thing to cut. Water, tea, coffee without sugar — as the base.
Losing 5–10% of body weight: the strongest lever in type 2
If you're overweight, no single change works as powerfully as losing 5–10% of your body weight — it improves insulin sensitivity, lowers fasting glucose and HbA1c, and in some people with short-standing type 2 diabetes it even leads to remission (with a larger reduction, always under a doctor's supervision — because medications then have to be adjusted). How to work out a safe pace and not lose muscle along the way is set out in our article on calories for weight loss.
Movement after a meal: 10–15 minutes you can see on the meter
A short walk after your main meal noticeably lowers post-meal glucose — working muscles use glucose without insulin. It doesn't replace treatment, but it's a free, immediate tool that's easy to weave into your day.
HbA1c and self-monitoring: look at the trend, not a single reading
A single meter reading is a snapshot. What counts is the trend: post-meal averages, morning fasting glucose and above all HbA1c, which shows the average over ~3 months (which is why checking it more often than every ~3 months usually makes no sense). A good loop looks like this: a change on your plate → post-meal readings → an adjustment → HbA1c a quarter later. For that to work, your results have to be in one place, not in a drawer and three apps.
A sample day (with approximate carbs)
This isn't a meal plan to copy out — it shows the logic instead: protein and vegetables in every meal, carbs with fibre and in a sensible portion.
| Meal | Example | ~carbs |
|---|---|---|
| Breakfast | Scrambled eggs (3 eggs) + vegetables + a slice of rye sourdough bread | ~15–20 g |
| Lunch | Chicken breast + a large portion of vegetables + ½ cup of buckwheat groats | ~25–30 g |
| Afternoon snack | Skyr/quark + a handful of nuts + berries | ~10–15 g |
| Dinner | Salad with legumes (chickpeas) + olive oil + egg | ~20 g |
You start with vegetables and protein, eat the carbs last, and take a short walk after lunch. Match the exact portions to your own readings and goals — and, if you take insulin, to the ratio set with your doctor.
How Bilberry takes the counting off your hands
All the theory above runs into one thing: counting carbs from tables is boring and quickly abandoned. Bilberry does it for you:
Carbs from a photo or description. Photograph your plate or write down what you're eating — the AI estimates the calories and carbs (and so the exchanges too), and you correct it if needed. Instead of giving up on counting, you simply see it.
A meal plan that watches your glucose. The weekly plan (home cooking, within your budget, with a shopping list) is built to keep carbs in check and reach for lower-glycemic-load foods — and the foods you can't eat are hard-excluded, not left in out of politeness.
Glucose and HbA1c on one timeline. Upload your results (a photo or PDF) — the AI reads off your glucose and HbA1c (you approve every value), and each new reading lands on the timeline, so you can see whether the changes on your plate are translating into numbers.
Once more, because it really matters: diet supports the treatment of diabetes, but does not replace it. Glucose targets, medications and insulin doses are always the doctor's decision. The best results come from a pairing: a diabetologist for the treatment and a well-informed plate every day.
Frequently asked questions
Can someone with diabetes eat fruit? Yes — whole (not as juice) and in a sensible portion. Berries, apple and pear have a moderate glycemic load; fruit juice acts almost like a sugary drink, because it has no fibre and a large dose of sugar.
Do I have to count every gram of carbs? If you take mealtime insulin — yes, counting carbohydrate exchanges is the basis of your dosing (the ratio set with your doctor). Without insulin, a good sense of "how many carbs and of what quality" is enough, and the principles do the rest: protein and vegetables in every meal, liquid sugars gone.
Potatoes, rice, pasta — cut them out? No need. Watch the portion, choose wholegrain, cook al dente and — the resistant-starch trick — eat them cooled too. Always in the company of protein, fat and vegetables.
Can diet reverse type 2 diabetes? In some people, especially those with short-standing disease and a significant weight reduction, remission is possible (normal glucose without medication). It's always a process guided by a doctor — because as things improve, medications have to be reduced to avoid causing hypoglycaemia.
And "diabetic" products and sweeteners? "Diet" products are sometimes just marketing — read the label (they often have a lot of fat, or plenty of carbs anyway). Calorie-free sweeteners can help you move away from sugar in drinks; treat them as a bridge, not a goal.
Count carbs without the charts
Bilberry estimates the calories and carbs from a photo of your meal, builds a plan that keeps your glucose in check and gathers your glucose and HbA1c on one timeline. 14 days free, no card required.
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