It is good to aim to have your blood glucose levels in the range (4mmol/L – 8mmol/L) for 80% of the time. Everyone goes high sometimes. A high of up to 14mmol/L every now and then is okay as long as it settles back down again within the day. https://www.diabetes.org.nz/type-2-diabetes-hyperglycaemia

The HbA1c test measures your average blood glucose (sugar) levels over 3 months. It is used in 2 ways – to diagnose type 2 diabetes, and to check your blood glucose levels if you have already been diagnosed with type 2 diabetes.

HbA1c is what’s known as glycated haemoglobin. Haemoglobin (Hb) is the protein in your blood that carries oxygen around your body. Glucose (a type of sugar) in your blood can stick to the haemoglobin protein. When this happens the haemoglobin is called glycated haemoglobin or HbA1c. The higher the glucose (sugar) levels are in your blood, the more of it attaches to your haemoglobin and the higher your HbA1c level is.

The HbA1c test measures the amount of glucose that has built up in your blood over a 3-month period. The HbA1c test can be done at any time of the day. It doesn't matter whether you have eaten or not. It is reported as millimoles per mole (mmol/mol).

Normal HbA1c: A result of 40 mmol/mol or lower is normal for people without diabetes or pre-diabetes.
An HbA1c level between 41-49 mmol/mol indicates you have prediabetes (also called impaired glucose tolerance or IGT) which means you are at much higher risk of getting type 2 diabetes and heart disease. Finding out you have prediabetes can be a chance to make changes. You may be able to stop it progressing to type 2 diabetes.
Type 2 diabetes: If you have symptoms of diabetes (such as excessive thirst, frequent peeing, or recurrent infections), only one high HbA1c result (50 mmol/mol or higher) is needed to confirm the diagnosis. If you do not have symptoms of diabetes, two high HbA1c results (50 mmol/mol or higher) are needed to confirm the diagnosis.
Once you have diabetes, you have it for life. But early treatment, including having a healthy lifestyle, can help to reduce damage to your eyes, kidneys, heart, feet and brain.

If you have prediabetes, you won't necessarily develop type 2 diabetes, especially if you take steps to prevent it from happening. Healthy lifestyle choices, such as maintaining a healthy weight, exercising, and eating a balanced diet, can help reverse prediabetes and prevent its progression to diabetes. Work closely with your healthcare provider or a registered dietitian to ease into healthier eating habits.

4 grams of sugar = 1 teaspoon.
There are 16 calories in 1 teaspoon of Sugar.

12 grams sugar = 1 tablespoon (tbsp) sugar

For example: a can of soda contains 140 calories and 38 grams of sugar.

Food Suggestions

Instead of refined carbs, choose complex carbohydrates. These foods usually do not cause rapid blood sugar spikes because they are higher in fiber and are digested slower than simple carbs. Complex carbs also give you long-lasting energy and help you feel full for a longer time.

Whole grains (wild rice, brown rice, oatmeal, quinoa, and barley)
Starchy vegetables (corn, green peas, and potatoes)
Beans and legumes (black beans, kidney beans, black-eyed peas, split peas, and garbanzo beans)
Fresh fruit with granola (no sugar added)
Whole grain toast with nut butter
Dark chocolate-covered almonds

Unsweetened tea or herbal tea
Low-sugar fruit juice
Coffee (without added sugar)
Opt for whole-grain cereals with less than 5 grams of sugar and at least 3 grams of fiber per serving. 

Unsweetened Greek yogurt with berries

Eat This Instead
Swapping saturated fats for moderate amounts of healthy monounsaturated and polyunsaturated fats can improve your health. Examples of unsaturated fats include:

Avocados and avocado oil
Olive oil
Peanut butter
Nuts and seeds
unsweetened Greek yogurt. Nondairy yogurts, including those made with almond, soy, or coconut milk, are also available in low-sugar options.

Abdominal obesity. Many South Asians have a normal BMI, slim arms and legs, and a large belly. This is called abdominal obesity, and it’s more strongly associated with heart disease and diabetes than BMI. South Asians can develop diabetes with just a small amount of abdominal obesity. Plus, even those without abdominal obesity often have internal, hidden fat that covers their organs and contributes to chronic conditions.

In short, South Asians have a hereditary susceptibility to heart disease and diabetes. That genetic predisposition can interact with and amplify common lifestyle risk factors, like being physically inactive and eating an inflammatory diet, putting South Asians at a dangerously high risk.