All foods that contain carbohydrates, chocolate included, will raise blood sugar levels, not lower them. But the extent to which they do so differs from food to food. The effects of chocolate on blood sugar are conditioned by the cocoa content of the product and portion size. The higher the cocoa content and the lower the intake, the lesser the effects on blood sugar. The lower the cocoa content and the higher the intake, the more pregnant the effects. For example, even though it makes blood sugar go up slightly, since the rise is small and steady, it’s actually okay to have a couple of cubes of dark chocolate after a meal. But not the same can be said for low-cocoa options which may not be tolerated as well.
One way to predict the effects of chocolate on blood sugar is with the help of the glycemic index scale. The glycemic index (GI) measures how fast the carbohydrates in a food raise blood sugar levels. Below 55 is a low GI. Between 55-69 is a moderate GI. Between 70-100 is a high GI. Ideally, diabetics and anyone required to monitor their blood sugar levels should look for foods with as low a GI as possible. Low GI foods have reduced effects on blood sugar metabolism, meaning eating them does not cause blood sugar to go up fast and then come crashing down several hours later.
The glycemic index of chocolate ranges from values as low as 23 for dark chocolate (70% cocoa or higher and diabetic chocolate) to values higher than 50 for products with lower cocoa contents, higher sugar and sweet fillings. This means that anyone looking to prevent blood sugar spikes is better off choosing dark chocolate products with a high cocoa content, preferably over 70% cocoa. Even though more bitter tasting, dark chocolate has a low glycemic index and minimal effects on blood sugar, when eaten in moderation of course.
Even if it has a high cocoa content and no sweet fillings (whether milk, whipping cream, caramel, fruit, toffee and other such fillings), dark chocolate can still raise blood sugar levels if you eat too much of it. An excessive intake may mean eating half a tablet at once or small portions throughout the day, but still enough to fill up on carbohydrates and, in the case of diabetics, exceed recommended intakes. See Can Diabetics Eat Chocolate?
Carbohydrates (except fiber) basically get broken down into simple forms of sugar following digestion and then get absorbed in the bloodstream into this very form, hence the reason they contribute to (rise) blood sugar levels. When monitoring blood levels, you have to take into account carbohydrate intake per day and per meal and set a healthy limit for you. This means that if you want to enjoy a treat such as chocolate, you have to consider your intake of carbohydrates up to that point in the day and determine your chocolate serving size accordingly so that you don’t exceed your carbs requirements.
And since most of a person’s daily carbohydrate intake comes from plant foods such as vegetables, fruits, grains and even nuts and seeds, which meet one’s basic nutritional requirements, there is actually little room left for sweets such as chocolate, especially in a diabetic diet. This is why portion size is limited to only a couple of cubes at once for diabetics, for example. Preferably no more than 1-2 servings a day and definitely not everyday. Non-diabetics may eat more, but still limited amounts if they want to avoid fluctuations in blood sugar levels and the side effects that come with the highs and lows.
The effects of chocolate on blood sugar are further determined by when you eat it. For example, to minimize effects, it’s best to have the sweet treat during the day, whether it’s breakfast, lunch or a morning or midday snack. This way, you have enough time and chances to use up the carbs (physical activity helps regulate post-meal blood glucose levels which also means a better insulin response). If you have chocolate at night, there are fewer chances to use up the carbs and regulate your blood glucose response with the help of physical activity. The more you eat, the more likely and pregnant the side effects, especially if you’re diabetic. Also, eating chocolate at night, dark or not, sets you up for acid reflux, heartburn and even insomnia, palpitations and extrasystoles.
What you pair your chocolate with also affects its glycemic value. For example, dark chocolate with nuts or seeds (hazelnuts, peanuts, almonds, walnuts etc.) is a far better option than milk, caramel, whipped cream, toffee-filled or chocolate with sweet fruit filling. Dark chocolate has slightly more fiber from cocoa and cocoa butter to delay the rate of sugar absorption into the bloodstream. Nuts and seeds further provide fiber and fats as well as protein, all of which contribute towards the same effects.
On the other hand, chocolate with less than 35% cocoa content has an overall high carb content. Fillings such as milk, whipped cream, caramel, toffee, fruits fillings add significant amounts of sugar to the product and raise carb content as well as maximize effects on blood glucose metabolism. And, of course, the more you eat at once, the more pregnant the effects.
The effects of dark chocolate on blood sugar are comparable to those of diabetic chocolate, meaning they are minimal, so long as intake is kept low and according to individual nutritional requirements. But despite having some fiber and copious amounts of cocoa butter to slow down digestion and the rate of sugar absorption into the bloodstream, dark chocolate doesn’t actually lower blood sugar. It is still a source of carbohydrates and will raise blood sugar levels, just not by very much. It’s actually well tolerated in a diabetic diet and even provides some benefits for the condition.