Lunch buyers limiting sugar
If you want a fizzy mixer with lunch while keeping its sugar contribution low, compare sugars per 100ml and for the amount you will drink. Read the ingredients too if particular sweeteners matter to you.
Who is each mixer for?
The useful distinction is whether you want to limit sugar, keep tonic flavour or avoid sweeteners as well.
Tonic drinkers considering a light version
A light tonic may suit you if you want tonic flavour and do not require a sugar-free drink. Compare its nutrition panel with the regular product named in any calorie-reduction claim; do not assume the claim applies to other brands.
Shoppers avoiding sugar and sweeteners
Plain soda water offers carbonation without the sweetness of a diet tonic. Fentimans lists 0g sugar per 100ml for its Soda Water, whose stated ingredients are carbonated water, salt and sodium bicarbonate.
What should you check before choosing?
Choose the type of drink you want, then compare the exact product labels on the same per-100ml basis and consider the portion you will carry.
Diet or sugar-free tonic
Choose it when: You want tonic flavour while keeping the mixer’s sugar contribution low.
Bear in mind: A diet tonic may use sweeteners; check its ingredients if you avoid them.
Light tonic
Choose it when: You want tonic flavour and accept some sugar in a product described as lower-calorie than its regular counterpart.
Bear in mind: A lower-calorie claim does not establish that the drink is sugar-free.
Plain soda water
Choose it when: You want an unsweetened carbonated drink without sugar or sweeteners.
Bear in mind: It does not provide tonic’s flavour.
| Priority | What to check | Your needs |
|---|---|---|
| Sugars | Compare sugars per 100ml, then consider how much you will drink. Sainsbury’s lists less than 0.5g per 100ml for its Diet Indian Tonic Water with Lemon; Fentimans lists 3.4g per 100ml for Naturally Light Tonic. | I want to keep the mixer’s sugar contribution low at lunch, rather than rely on the word “light” on the front of the pack. |
| Calories | Read the kcal figure per 100ml and the serving size. If a brand gives a percentage reduction, check which regular product it uses for comparison. | A lighter version appeals to me, but I still want to know what is in the amount I plan to drink. |
| Ingredients | Look for sugars such as fructose and for named sweeteners. Sainsbury’s lists acesulfame K and sucralose in its Diet Indian Tonic Water with Lemon. | If I avoid particular sweeteners, the ingredients list matters as much as the sugars figure. |
| Flavour | Decide whether you want tonic, a different flavoured mixer or plain soda water. Check the exact product rather than treating these as interchangeable drinks. | I would choose soda water for an unsweetened drink, but tonic if its flavour is part of what I want. |
| Portion | Check the can or bottle volume against the per-100ml nutrition figures. Consider whether an individual can or an opened larger bottle suits your lunch plans. | A single portion is easier for me to take along; with a larger bottle, I need to follow its storage instructions after opening. |
Common label mistakes
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Treating “light” and “sugar-free” as the same thing
A lower-calorie tonic can still contain sugar. Fentimans lists 3.4g sugar per 100ml for Naturally Light Tonic, while Sainsbury’s lists less than 0.5g per 100ml for its Diet Indian Tonic Water with Lemon.
Compare sugars and kcal per 100ml on the exact drinks you are considering, then account for the amount you will have.
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Assuming a diet tonic has no sweeteners
Some diet tonics use sweeteners: Sainsbury’s lists acesulfame K and sucralose in its Diet Indian Tonic Water with Lemon.
Read the ingredients if you avoid particular sweeteners. If you prefer an unsweetened drink and do not need tonic flavour, consider plain soda water.
Brand and retailer examples
These examples show why the product name alone is not enough: check the nutrition and ingredients of the particular variant you intend to buy.
Fever-Tree
Its Refreshingly Light Indian Tonic is a light-tonic option rather than an assumed sugar-free one.
- Fever-Tree describes this product as having 50% fewer calories than its regular Premium Indian Tonic Water.
- Its ingredient list includes fructose. The calorie comparison does not establish a zero-sugar drink.
Schweppes
Slimline Tonic Water is a tonic option for shoppers looking beyond light varieties.
- Tesco describes its listed Schweppes Slimline Tonic Water as a no-sugar, low-calorie soft drink with quinine and sweetener.
- Check the label of the pack you choose for its ingredients and nutrition.
Fentimans
Its Naturally Light Tonic and Soda Water serve different preferences.
- Fentimans lists 18kcal and 3.4g sugar per 100ml for Naturally Light Tonic, which it describes as having 30% fewer calories than its Premium Indian Tonic.
- Its Soda Water lists 0kcal and 0g sugar per 100ml, with no artificial sweeteners in its stated formulation.
- Soda water does not provide tonic flavour; Naturally Light Tonic is not sugar-free.
Britvic
Britvic has described classic and zero-sugar Indian Tonic Water in 330ml cans.
- In a September 2023 launch announcement, Britvic identified both variants in the 330ml can format.
- Check the current product label when choosing between the variants; the launch announcement does not establish the formulation of a pack bought now.
Sainsbury’s
Its Diet Indian Tonic Water with Lemon provides a specific example of a low-sugar diet tonic.
- Sainsbury’s lists 2kcal and less than 0.5g sugars per 100ml for this product.
- It contains acesulfame K and sucralose, which matters if you avoid those sweeteners.
Tesco
Tesco’s low-calorie mixer category has included own-label tonic alongside Schweppes and Fever-Tree products.
- Comparing individual product labels can help distinguish diet, slimline and light variants.
- Check the current product page or pack for the particular variant you intend to buy.
Joybuy mixer options
These options include portioned Slimline tonic, Refreshingly Light tonics and a Refreshingly Light ginger ale for taking along with lunch. The ginger ale is a different flavour choice, not another tonic; use each pack’s label to check whether it meets your sugar and ingredient preferences.
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Schweppes Slimline Tonic Water, 12 × 150ml
The 150ml cans offer individual portions for lunch on the go. If limiting sugar or avoiding a particular sweetener is important, check the nutrition panel and ingredients on this pack.
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Fever-Tree Refreshingly Light Premium Indian Tonic Water, 15 × 150ml
This light Indian tonic comes in individual 150ml cans for taking along. “Light” is not a sugar-free description: check this pack’s sugars figure and ingredients before choosing it to limit sugar.
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Fever-Tree Refreshingly Light Mediterranean Tonic Water, 8 × 150ml
The 150ml cans provide individual portions of Mediterranean tonic for lunch on the go. Compare the sugars figure and ingredients on this variant’s label if you are choosing between light and sugar-free mixers.
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Fever-Tree Refreshingly Light Ginger Ale, 8 × 150ml
Choose this 150ml-can format if you want a ginger ale mixer to take with lunch rather than tonic. Check the sugars figure for this light variant instead of assuming it is sugar-free.
Frequently asked questions
Does “light” tonic mean sugar-free?
No. A light tonic can still contain sugar: Fentimans lists 3.4g sugar per 100ml for Naturally Light Tonic, and Fever-Tree lists fructose in the ingredients of its Refreshingly Light Indian Tonic. Check the sugars figure and ingredients for the exact product.
What if I want neither sugar nor sweeteners?
Consider plain soda water if you are happy without tonic flavour. Fentimans lists 0g sugar and 0kcal per 100ml for its Soda Water; its stated ingredients are carbonated water, salt and sodium bicarbonate.
Can a diet mixer help me cut down on free sugars?
A diet mixer can be an alternative to a sugary fizzy drink when its label confirms low or no sugar. NHS guidance suggests sugar-free, diet or no-added-sugar drinks in place of sugary fizzy drinks; compare the sugars figures because formulations differ.
How should I keep a larger tonic bottle after opening it?
Follow the instructions on the bottle you buy. For its 1L Diet Indian Tonic Water with Lemon, Sainsbury’s says to refrigerate after opening and use within three days.