Calories and Nutritions in Sourdough Bread

A 100g (3.53oz) serving of sourdough bread contains 289 calories. A 100g (3.53oz) serving of homemade sourdough bread contains 252 calories. A 100g (3.53oz) serving of whole wheat sourdough bread contains 260 calories.

A 1kg (2.2lb) serving of sourdough bread contains 2,890 calories. A 1kg (2.2lb) serving of homemade sourdough bread contains 2,520 calories. A 1kg (2.2lb) serving of whole wheat sourdough bread contains 2,600 calories.

One loaf of sourdough bread weighing 680g (24oz) contains 1,965 calories. One loaf of homemade sourdough bread weighing 900g (31.7oz) contains 2,268 calories. A loaf of whole wheat sourdough bread weighing 680g (24oz) contains 1,768 calories.

There are 113 calories in one sourdough bread slice (39g or 1.4oz). A slice of homemade sourdough bread weighing 47g (1.7oz) contains 118 calories. A slice of whole wheat sourdough bread weighing 45g (1.6oz) contains 117 calories.

Sourdough bread consumption is associated with several health advantages, which are detailed below:

• Improved Digestibility: The fermentation process used to make sourdough bread breaks down some of the gluten and anti-nutrients like phytates found in flour. This action can make the bread easier to digest for some individuals compared to conventional bread. A study by Rizzello et al. demonstrated this effect. (Rizzello, C. G., et al., 2007, Highly efficient gluten degradation by lactobacilli and fungal proteases during food processing: new perspectives for celiac disease)
• Enhanced Nutrient Absorption: Sourdough fermentation reduces the levels of phytic acid in bread. Phytic acid can bind to minerals like calcium, iron, and zinc, preventing their absorption. By lowering phytic acid, sourdough bread allows for greater bioavailability of these important minerals. Research supports this mineral availability benefit. (Leenhardt, F., et al., 2005, Moderate decrease of pH by sourdough fermentation is sufficient to reduce phytate content of whole wheat flour through endogenous phytase activity)
• Better Blood Sugar Control: Sourdough bread has a lower glycemic index (GI) compared to many other types of bread. This means sourdough bread causes a slower, more gradual rise in blood sugar levels after consumption, which is beneficial for managing blood sugar and may reduce the risk of type 2 diabetes. A study confirmed the lower glycemic response. (Maioli, M., et al., 1988, Sourdough-leavened bread improves postprandial glucose and insulin plasma levels in subjects with impaired glucose tolerance)

Sourdough bread is a healthy option but some considerations exist, which are discussed below:

• Contains Gluten: Sourdough bread is not gluten-free. While the fermentation process degrades some gluten proteins, enough gluten remains to be harmful for individuals with celiac disease or a non-celiac gluten sensitivity. An alternative for these individuals would be certified gluten-free bread. There is no safe daily suggested amount for people with celiac disease. (Di Cagno, R., et al., 2004, Sourdough bread made from wheat and non-toxic flours and started with selected lactobacilli is tolerated in celiac sprue patients)
• High Sodium Content: Commercially prepared and homemade sourdough bread can be high in sodium, with a single slice containing up to 10% of the recommended daily intake. High sodium consumption is linked to increased blood pressure and risk of heart disease. An alternative is to make homemade sourdough and control the amount of salt used. A daily suggested amount for healthy adults is to consume less than 2,300mg of sodium from all sources. (Appel, L. J., et al., 2011, A clinical trial of the effects of dietary patterns on blood pressure)
• Acidity May Affect Some Individuals: The natural acids produced during sourdough fermentation, which give the bread its characteristic tangy flavor, may cause discomfort for individuals with sensitive stomachs or acid reflux. An alternative would be a less acidic bread, like a standard whole wheat loaf. A daily suggested amount would depend on individual tolerance. (Festek, D., et al., 2008, Gastroesophageal reflux disease: a clinical-pathological review)

Yes, sourdough bread is good for health because of its unique fermentation process. This fermentation improves digestive health by breaking down gluten and anti-nutrients, making the bread easier to digest for many people (Rizzello, C. G., et al., 2007, Highly efficient gluten degradation by lactobacilli and fungal proteases during food processing). The process also enhances nutrient absorption. Sourdough fermentation reduces phytic acid, which allows the body to better absorb minerals like iron, zinc, and magnesium, supporting overall mineral status (Leenhardt, F., et al., 2005, Moderate decrease of pH by sourdough fermentation is sufficient to reduce phytate content of whole wheat flour through endogenous phytase activity). For metabolic health, sourdough bread has a lower glycemic index than conventional bread, promoting better blood sugar regulation and providing sustained energy, which is beneficial for managing metabolic conditions (Maioli, M., et al., 1988, Sourdough-leavened bread improves postprandial glucose and insulin plasma levels in subjects with impaired glucose tolerance).

Yes, overeating sourdough bread can lead to side effects. Consuming any food in excessive amounts, including sourdough bread, can cause weight gain due to a surplus of calories. The high fiber content in whole wheat sourdough, when eaten in large quantities, may lead to digestive discomfort such as bloating, gas, and cramping (Slavin, J. L., 2013, Fiber and Prebiotics: Mechanisms and Health Benefits). This overconsumption leads to a health risk by potentially exceeding daily sodium limits, as sourdough bread contains a notable amount of salt, which can elevate blood pressure over time (He, F. J., & MacGregor, G. A., 2009, A comprehensive review on salt and health and current experience of worldwide salt reduction programmes). Exceeding carbohydrate goals from overeating bread can also pose a risk for individuals managing blood sugar levels (Ludwig, D. S., et al., 2018, Dietary carbohydrates: role of quality and quantity in chronic disease).

The calorie content of sourdough bread changes based on the type of flour used. Classic white sourdough made from refined flour has the highest calorie count, at 289 calories per 100g. Whole grain versions like whole wheat sourdough (260 calories) and rye sourdough (259 calories) have fewer calories due to a higher fiber content. Spelt sourdough is the lowest in calories among these common types, with 255 calories per 100g. Additions like seeds, nuts, or cheese will increase the calorie density of any sourdough bread type.

Sourdough bread is not a weight loss food, but can support weight management goals better than regular white bread due to higher protein and fiber, which can increase feelings of fullness. A person should choose sourdough over regular bread for better digestive health, nutrient absorption, and blood sugar control. The difference between sourdough and normal bread lies in the fermentation process. Sourdough uses a wild yeast and lactic acid bacteria culture, while regular bread uses commercial baker's yeast. This natural fermentation in sourdough breaks down complex carbohydrates and some gluten, making sourdough easier to digest (Rizzello, C. G., et al., 2007).

So, is sourdough healthier than regular bread? Yes, because the fermentation process also reduces phytic acid, an anti-nutrient that hinders mineral absorption. This reduction means minerals like iron, zinc, and magnesium are more available to the body (Leenhardt, F., et al., 2005). Sourdough bread has a lower glycemic index, leading to a slower release of sugar into the bloodstream, which is beneficial for metabolic health compared to the sharp spike from regular white bread (Maioli, M., et al., 1988).

The difference between Sourdough and regular bread in terms of macros is in the bioavailability of the nutrients. The sourdough bread macros are compositionally similar to regular bread made from the same flour, but the fermentation process alters them. Sourdough has a comparable amount of carbohydrates, but the fermentation process can lower the bread's glycemic index, affecting how the body processes those carbs (Maioli, M., et al., 1988). Sourdough and regular bread have similar protein content, but the fermentation may make the amino acids in sourdough protein more digestible and available for the body to use (Thiele, C., et al., 2002, Contribution of sourdough lactobacilli, yeast, and cereal enzymes to the generation of amino acids in dough). Sourdough bread does not contain unique macronutrients not found in regular bread, but the fermentation process makes the existing nutrients, including minerals, more accessible by reducing phytic acid (Leenhardt, F., et al., 2005).

The origin of sourdough bread dates back to ancient Egypt around 1500 BCE, where bakers first discovered that wild yeast and bacteria present in the air and on grain could leaven dough, creating a lighter, more flavorful bread than unleavened flatbreads. This method of natural fermentation became the standard for bread-making throughout Europe for millennia. The bread's modern identity is strongly linked to the San Francisco Gold Rush in the 1840s. Prospectors carried sourdough starters with them for a reliable leavening agent, and the unique foggy climate of the San Francisco Bay Area proved ideal for a specific, tangy strain of bacteria, later named Lactobacillus sanfranciscensis. This local culture gave San Francisco sourdough its world-famous flavor. The iconic dish of clam chowder in a sourdough bread bowl was popularized in San Francisco at restaurants like Boudin Bakery, which was established in 1849. After a period where commercial yeast dominated, sourdough experienced a major revival in the late 20th century with the rise of the artisan bread movement in America and Europe, which celebrated traditional baking techniques and the complex flavors of naturally leavened bread.