Low Carb Beers Common Myths

Glycemic index of beer

The exact science of carbohydrate metabolism, is complex and dynamic. It is not uncommon popular low carbohydrate diet books to dumb down these difficult concepts by calling food “good” or “bad” based on its “glycemic index” alone.

The glycemic index is a way of measuring how quickly and much a particualar food increases blood sugar. There are two main methods for measuring glycemic index and as yet there is no consensus among doctors or nutritionists that glycemic index alone is a reliable way to choose foods for weight loss or improving body composition.

When it comes to beers, wines spirits and liqueurs, many diet book writes rate beer’s glycemic index as high,  even low carb beers.  Though this is based on the mistaken idea that beer contains high levels of sugar or maltose, which is in fact not true.

So, what is the correct glycemic index of beer?

For now this question is difficult to answer. Some sources say low carb beer contains not enough carbohydrate for glycemic index.  Measuring the glycemic index of a food typically needs the food be eaten in about 15-minutes in a quantity that delivers 50 grams of carbohydrates. The blood sugar is then recorded over time and the results are compared to the blood sugar response of a standard food, such as white bread or glucose.

The problem with testing beer this way is that all beers are relatively low in carbs. It would require a person to drink, for example, 7.5 light beers within 15 minutes to consume the 50 grams necessary to measure the resulting blood sugar. That is not responsible consumption of beer by adults.

Beer’s glycemic “value” is very low.

Many carb diet books focus on glycemic index. But several experts warn against using glycemic index alone when choosing foods because it does not account for serving size, the effect of eating different foods together in one meal, which is how most people eat, or other factors.

For this reason, some experts suggest that a more important measure is the “glycemic load,” which adjusts glycemic index for serving size. (Multiply glycemic index by the number of carbs per serving and divide by 100.) Glycemic load provides a better idea of how a single serving has an impact on blood sugar.

If you select your food based on glycemic index (GI) alone, then you would have little guilt eating chocolate cake, while watermelon would be forbidden. But when you account for carbohydrates per serving, watermelon’s glycemic load (GL) is much lower, and much preferred, than the chocolate cake.




Beer’s glycemic index has not been published. However, even if beer’s glycemic index were determined to be 70, the glycemic load for Bud Light, for example, would be 4.6. Less than 10 is considered low.