Drinks People with Diabetes Can Have and Should Avoid

Why Is Choosing Drinks So Important in Diabetes?

When managing diabetes, most people focus on sweets and flour-based foods; however, drinks can raise blood sugar just as quickly, or sometimes even faster. Because it contains no fibre, a sugar-sweetened drink delivers glucose rapidly into the bloodstream and can use up the day's entire “sugar budget” at once.

According to WHO, free sugar intake should be kept below 10% of daily energy (preferably below 5% ≈ 25 g/day). A single can (330 ml) of cola contains approximately 35–40 g of sugar; in other words, this choice alone can exceed the ideal daily limit. ADA also recommends, in diabetes management, avoiding sugary drinks and choosing calorie-free options such as water.

What Is in This Article?

• The 5 best drinks: Water, unsweetened tea/coffee, milk/ayran/kefir, vegetable juice and appropriately selected plant-based milks.
• 5 drinks to avoid: Sugary soft drinks, energy drinks, fruit juices/nectars, excessive use of “diet” drinks and risky alcohol choices.
• Table + numbers: A comparison of sugar per serving (g), glycaemic index (GI) and the more practically meaningful glycaemic load (GL).
• Practical tips: Reading labels, awareness of “free sugars”, and monitoring blood sugar on exercise/alcohol days.

A Quick Message in 30 Seconds

• Your basic drinks: Water and unsweetened tea/coffee. Let these provide most of your daily fluid intake.
• Milk/ayran/kefir: A low GI and moderate portions help keep you full; look for added sugar on labels.
• Fruit juice: No fibre → a rapid glucose rise. If consumed, keep it to ≤100 ml and dilute it.
• Diet/“zero”: Compared with sugary counterparts, safer, but not unlimited. Limit it to a few times a week.
• Alcohol: Risk of delayed hypoglycaemia. Consume it with food, monitor, reduce the amount.

GI Alone Is Not Enough: Why Does GL Matter?

Glycaemic index (GI) indicates speed; glycaemic load (GL) indicates both speed and carbohydrate quantity. Put simply: GL = GI × carbohydrate (g) / 100. For example, for 250 ml of 100% orange juice, GI ~45 and ~22 g of carbohydrate → GL ≈ 10. For 330 ml of cola, GI ~60 and ~35 g of carbohydrate → GL ≈ 21. Therefore, throughout the article, GI + GL will be considered together.

Hydration: The Question of “How Many Glasses of Water?”

Requirements vary with climate, activity, medication and coexisting conditions. A practical starting point is to aim for 8–10 glasses of water throughout the day. NAM (formerly IOM) guidelines recommend total water intake (including water from food) of ~3.7 L for men and ~2.7 L for women. Good hydration in diabetes helps tolerate osmotic diuresis during periods of hyperglycaemia and supports general well-being.

Which Drinks Can People with Diabetes Have?

With appropriate portions and preparation methods, the following drinks tend to have a low impact on blood sugar. For each drink, we provide serving size, approximate GI/GL and practical tips.

1) Water

It does not raise blood sugar and is the main source of hydration. During hyperglycaemia, it helps tolerate the fluid loss accompanying osmotic diuresis.

• Serving: Spread throughout the day, 8–10 glasses as an initial target (individualized).
• GI/GL: 0 / 0
• Practical tip: If plain water is difficult to drink, try lemon, mint or cucumber slices, ice, or a half-and-half mixture with sparkling mineral water.

2) Unsweetened Tea (Including Herbal Teas)

It is calorie-free; black/green tea contains antioxidants. Moderation matters with caffeinated tea; herbal teas (linden, sage, chamomile) contribute to hydration throughout the day.

• Serving: 1–3 cups of herbal tea; for black/green tea, try not to exceed 2–3 cups per day.
• GI/GL: 0 / 0 (unsweetened)
• Practical tip: Use a slice of lemon instead of sugar; reduce caffeinated tea in the evening.

3) Unsweetened Coffee

When prepared without sugar or syrup, its effect on blood sugar is nearly neutral. Some studies have reported benefits for type 2 diabetes risk; the key is unsweetened, moderate consumption.

• Serving: Per day, 1–2 cups (filter/espresso). Avoid late hours.
• GI/GL: 0 / 0 (unsweetened)
• Practical tip: Instead of syrup and cream, use cinnamon or a small amount of semi-skimmed milk.

4) Vegetable Juice (Predominantly Green Mixtures)

When prepared with leafy greens and low-sugar vegetables, it has a low carbohydrate load and provides vitamins, minerals and antioxidants.

• Serving: 1 glass (≈250 ml), preferably with fibre (blended/puréed).
• Approximate GI/GL: GI 15–30; CHO ~3–5 g → GL ≈ 1 (depending on the recipe).
• Practical tip: Use spinach, parsley, cucumber and celery stalks as a base; limit carrot/beetroot; do not add salt.

5) Milk, Ayran and Kefir

They contain lactose, but the GI is low because it is absorbed alongside protein and fat; they promote fullness and provide calcium/protein. Fermented kefir may be easier to digest.

• Serving: 1 glass (≈250 ml).
• Approximate GI/GL: Milk GI ~30; CHO ~12 g → GL ≈ 4. Ayran ~5–7 g → GL ≈ 2. Kefir ~8–10 g → GL ≈ 3.
• Practical tip: Look for “no added sugar” on the label; keep the salt content of ayran low.

6) Plant-Based Milks (Unsweetened)

Unsweetened almond, soya and coconut milks offer a low sugar load. Soya milk stands out for its protein balance; almond milk can be very low in calories/sugar but is low in protein and calcium (choose fortified versions).

• Serving: 1 glass (≈250 ml), unsweetened labelling is essential.
• Approximate GI/GL: Unsweetened almond/soya → GL ≈ 0–1 (depending on brand/label).
• Practical tip: Look for the labels “unsweetened”, “no added sugar”, “calcium-fortified”.

Which Drinks Should People with Diabetes Avoid?

The following drinks make diabetes management harder because of their high sugar load, high GI/GL or metabolic side effects. Avoid them or at least limit them to very rare, small servings.

1) Sugary Soft Drinks and Fizzy Drinks

A can (330 ml) of cola contains ≈ 35–40 g of sugar (10 teaspoons) and ≈150 kcal. GL ≈ 21 means it raises blood sugar rapidly.

• Serving: Avoid. “Light/zero” alternatives only very rarely.
• Alternative: Sparkling water + lemon/mint → satisfies the desire for carbonation.

2) Energy Drinks

250 ml of an energy drink contains ≈ 25–30 g of sugar + 80 mg of caffeine. GL ≈ 15–18. It may trigger blood sugar fluctuations, palpitations and sleep problems.

• Avoid: It does not provide energy during exercise; it increases stress, hypertension and insulin resistance.
• Alternative: During prolonged exercise, choose sugar-free electrolyte drinks.

3) Fruit Juices (Including Freshly Squeezed)

A glass (250 ml) of orange juice contains ≈ 20–25 g of sugar; without fibre, it is absorbed rapidly. GL ≈ 10.

• Rule: Do not choose it. If you insist on having it, keep it to ≤100 ml and dilute with water.
• Alternative: Eating whole fruit → a more balanced glucose response thanks to fibre.

4) “Diet” Drinks with Sweeteners

They do not raise blood sugar (GI/GL=0), but metabolic effects and potential risks for the gut microbiota remain debated. They may also increase appetite.

• Rule: Safer than sugary counterparts, but not unlimited. Limit them to a few times a week.
• Alternative: Unsweetened tea/coffee, sparkling water + lemon.

5) Alcoholic Drinks

Beer (330 ml) ≈ 12–15 g of sugar, GI ≈ 70, GL ≈ 8–10. Sweet wines/cocktails have a much higher load. Alcohol also carries a risk of delayed hypoglycaemia.

• Rule: With a doctor's approval, ≤1 standard drink/day for women and ≤2 for men, provided it is not regular.
• Precaution: Never drink on an empty stomach; consume with food and monitor blood sugar at night.

Conclusion

In diabetes, choosing drinks is at least as important as choosing food. Water, unsweetened tea/coffee, ayran, kefir and vegetable juices are safe and beneficial choices for daily hydration. By contrast, sugary soft drinks, energy drinks and fruit juices/nectars disrupt blood sugar control through their high sugar load. Although “diet” drinks are safer than sugary counterparts, they are not unlimited. Alcohol should only be consumed with a doctor's approval and in very moderate amounts.

Remember: the aim of diabetes management is not only controlling blood sugar, but protecting overall metabolic health. Choosing drinks appropriately is a simple yet powerful step towards a better daily quality of life.

Frequently Asked Questions (FAQ)

💧 How much water should people with diabetes drink each day?

General recommendation: men ~3.7 L, women ~2.7 L of total water (food + drinks). In practice, 8–10 glasses of water is a useful anchor point. Hydration is even more important during hyperglycaemia because fluid loss in urine increases.

🍊 Can people with diabetes drink fruit juice?

It is not recommended. With no fibre, it raises blood sugar rapidly. If strongly desired, keep it to 100 ml (100% pure) at most and always dilute it with water. The best choice is eating the fruit itself with its pulp.

🥤 Are diet/zero drinks completely safe?

They do not raise blood sugar (GI/GL=0), but metabolic effects are debated. Adverse effects on gut microbiota and appetite have been reported. Rule: Better than sugary counterparts, but they should not be a daily fluid source. Limit them to a few times a week.

🍷 Can people with diabetes drink alcohol?

With a doctor's approval, in very moderate amounts it may be possible. A daily limit of ≤1 standard drink for women and ≤2 for men is accepted. Never drink on an empty stomach; take it with food and, at night, to guard against hypoglycaemia, monitor blood sugar.

📌 Summary Message

• Safe drinks: Water, unsweetened tea/coffee, ayran, kefir and vegetable juices.
• Limited drinks: Plant-based milks (unsweetened), diet drinks.
• Drinks to avoid: Sugary soft drinks, energy drinks, fruit juices and sweet cocktails.
• Alcohol: Moderation + food + monitoring = safer.