Nutritional Information for Dark Chocolate
Dark chocolate is a calorie-dense food at around 530-550 kcal per 100g, but its glucose impact varies enormously depending on cocoa percentage. A 70% cocoa dark chocolate contains roughly 30g of sugar per 100g, while standard milk chocolate hits 55g+ — nearly double. From a SpikeSaver perspective, the higher the cocoa content, the lower the sugar and the better the blood sugar response. Most dark chocolate bars are NOVA 3-4 due to processing, with common additives including soya lecithin (emulsifier) and flavourings. The fat content is high but predominantly from cocoa butter.
Nutrition per 100g
| Nutrient | Per 100g | Per serving |
|---|---|---|
| Energy | 546 kcal / 2270 kJ | 137 kcal |
| Protein | 7.5g | 1.9g |
| Carbohydrates | 50g | 12.5g |
| of which sugars | 40g | — |
| Fat | 33g | 8.3g |
| of which saturated | 20g | — |
| Fibre | 8g | — |
| Salt | 0.03g | — |
Serving size: 4 squares (~25g) · Source: Tesco product page, October 2025
Glucose impact
Medium
Glucose risk
Dark chocolate has a medium glycaemic index of around 40-50, significantly lower than milk chocolate (GI ~50-60). The fat and fibre content slows sugar absorption. However, the sugar content varies hugely: a 70% cocoa bar contains around 30g sugar per 100g, an 85% bar around 15g, while a standard dark chocolate bar (45-50% cocoa) can contain 45-55g sugar per 100g. Choosing higher cocoa percentage is the single most effective way to reduce glucose impact.
Processing level
Even premium dark chocolate undergoes significant industrial processing: cocoa beans are fermented, roasted, ground, conched, and tempered. Most bars contain added sugar, cocoa butter, and emulsifiers (typically soya lecithin). Simpler bars with just cocoa mass, sugar, and cocoa butter sit at NOVA 3. Bars with added flavourings, vegetable fats, or multiple emulsifiers reach NOVA 4. The key differentiator is ingredient list length — shorter is better.
Dark Chocolate at Tesco
Source: Tesco product page, October 2025
1 UPF marker
2 UPF markers
*Prices were correct at the time of collection and may have since changed. Check Tesco.com for current pricing.
What to watch for when shopping
The sugar content in dark chocolate varies hugely and is the single most important thing to check. A 70% cocoa bar has roughly 30g sugar per 100g, an 85% bar around 15g, but a basic 'dark chocolate' bar (like Tesco Dark Chocolate Bar at 45-50% cocoa) can contain 43g sugar. Always check cocoa percentage and sugar per 100g. Watch for emulsifiers — soya lecithin is almost universal and relatively benign, but some brands add vegetable fats (palm, coconut) and flavourings that push them into NOVA 4 territory. Lindt Lindor truffles, for example, contain vegetable fat (coconut) alongside the cocoa butter.
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