Neither a classic custard cream nor a plain digestive is automatically a suitable choice for a strict keto eating pattern: the checked UK packs list 63.6–75.2 g of carbohydrate per 100 g, according to their retailer nutrition declarations. If you want an occasional conventional biscuit, compare the carbohydrate in the portion you would eat with your own allowance; a lower sugar figure or a free-from label does not settle that question. These examples do not establish a keto-friendly winner.
Check the carbohydrate in the number of biscuits you would actually eat before deciding whether a conventional custard cream or digestive fits your eating pattern. HEART UK describes a ketogenic diet as containing less than 50 g of carbohydrate a day.
If you want a familiar filled or plain biscuit, compare its labelled serving with your own allowance. A lower sugar figure is not a substitute for the total carbohydrate figure.
Check ingredient restrictions and carbohydrate separately. Tesco Groceries lists 10.5 g of carbohydrate per biscuit for its Free From Custard Creams, compared with 8.4 g for its conventional custard creams; those figures describe the labelled biscuits, not every free-from product.
Compare carbohydrate per 100 g to put different biscuits on the same weight basis, then use the labelled serving to assess the amount you plan to eat.
| Priority | What to check | Your needs |
|---|---|---|
| Carbohydrate per portion | Read total carbohydrate per biscuit where a serving is defined, and account for the number you intend to eat. The checked retailer labels range from 8.1 g to 10.5 g per biscuit. | I want to know what my actual portion contributes to a very-low-carbohydrate day, rather than judging a biscuit by its name. |
| Common-weight comparison | Compare carbohydrate per 100 g before comparing differently sized biscuits. The checked Tesco and Asda custard creams list 70.1 g and 68 g per 100 g; Tesco and McVitie's original digestives list 64.4 g and 63.6 g. | A smaller per-biscuit figure might reflect a smaller biscuit, so I want a like-for-like weight comparison as well as a serving figure. |
| Sugar and total carbohydrate | Read the carbohydrate and ‘of which sugars’ lines separately. Tesco Groceries lists 9.0 g carbohydrate and 2.0 g sugars per digestive, versus 8.4 g carbohydrate and 3.4 g sugars per custard cream. | If I prefer the less-sweet option, I still need to check its total carbohydrate rather than assuming it fits keto. |
| Ingredients and biscuit style | Check the particular pack's ingredients and allergen information for dietary exclusions. Distinguish a filled custard cream from a plain digestive or another sandwich biscuit. | I may want a vanilla-filled biscuit or a plain wheaty one, while keeping any ingredient restriction separate from the carbohydrate decision. |
The checked Tesco and McVitie's plain digestives list less sugar per biscuit than the checked classic custard creams, but still list 9.0 g and 9.3 g of total carbohydrate per biscuit, according to Tesco Groceries and Asda Groceries.
Use the total carbohydrate line for the portion you intend to eat.
Tesco Groceries lists 10.5 g of carbohydrate per biscuit for its gluten- and milk-free custard creams. The free-from description addresses ingredients, not that carbohydrate figure.
Check the ingredient restriction and the nutrition declaration as separate questions.
A per-biscuit carbohydrate figure describes that product's labelled serving. It does not, by itself, show which recipe has less carbohydrate at the same weight.
Compare per 100 g first, then check the carbohydrate for the number of biscuits you plan to eat.
The Original is a plain digestive option for shoppers who prefer a wheaty biscuit.
The checked Iceland Foods listing is for a 300 g pack of filled custard creams.
The checked range includes classic custard creams, plain digestives and Free From Custard Creams.
The checked 200 g custard creams provide another filled-biscuit comparison.
Asda's checked own-brand custard creams can be compared with its listing for McVitie's original digestives.
Extra Cream Custard Creams are a filled-biscuit variation described by M&S Food as having extra cream.
These Joybuy options comprise a digestive, an oat biscuit and two sandwich biscuits. A sugar-related claim in a product name does not establish whether its total carbohydrate fits a keto eating pattern; check the particular pack and portion.
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A digestive-style option if you prefer a plain biscuit. Check total carbohydrate on the pack for your intended portion; the sugar-free wording does not answer that question.
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An oat, dark-chocolate and ginger biscuit rather than a plain digestive or custard cream. Compare its labelled carbohydrate per 100 g and per portion with the biscuit style you originally wanted.
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A cookies-and-cream option to consider if you want a filled-biscuit style rather than a plain digestive. Check total carbohydrate and the labelled serving separately from its no-added-sugar wording.
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A sandwich biscuit, not a conventional custard cream. If its format appeals, use the pack's total carbohydrate and serving information to assess it rather than relying on the Zero Sugar name.
No. Asda Groceries lists 63.6 g of carbohydrate per 100 g for McVitie's original digestives, versus Tesco Groceries' 70.1 g for Tesco custard creams, but the labelled biscuits contain 9.3 g and 8.4 g respectively. Compare both the common-weight figures and the portion you would eat.
Not necessarily. Tesco Groceries lists 75.2 g of carbohydrate per 100 g and 10.5 g per biscuit for its Free From Custard Creams. Check ingredients for your restriction and total carbohydrate for your intended portion as separate decisions.
Check total carbohydrate per 100 g and for the labelled serving, then read sugars separately. Look at the current ingredient and allergen information for any dietary exclusion; a free-from or sugar-related description does not replace those checks.
Speak with your diabetes healthcare team before making significant dietary changes, as Diabetes UK advises. A comparison of biscuit labels cannot account for your medication or individual circumstances.