Weight Loss and Sourdough Bread

Weight Loss and Sourdough Bread

Like many of you, I am trying to lose weight. My goal is to get back to my 40-year-old runner’s weight and while I have lost 85 pounds in the last twelve months, I have a long, long way to go still.

I was doing great by eating a slice of my sourdough bread with every meal, then last year when Christmas came, I started gaining weight again. This was interesting since I stayed within my calorie budget most days. However, I was not eating as lean as I had, and certainly not as much bread; lots of sugar, fats, and sodas. In all, I packed 12 pounds back on in just twenty days!

As soon as our son’s family headed back to Dallas, I resumed my former eating plan. Now nearly twelve months later I am back on track, lost my holiday weight, and so much more. But this experience has left me asking, “Is bread really what is making the difference?” just because I was not eating a slice with each meal.

So my quest this week is to discover if sourdough bread may help with weight loss.


One decade ago, Professor Terry Graham and a team of six other Canadian researchers set out to see what bread might be best for overweight men to eat. They found that consuming whole-grain and sourdough bread regulates blood sugar better than commercial bread. Bread types included 11-grain, sprouted-grain, 12-grain, whole wheat, sourdough, and white bread. Test subjects’ response to sourdough was better than all bread tested.

“With the sourdough, the subjects’ blood sugar levels were lower for a similar rise in blood insulin,” said Graham. “What was even more interesting was that this positive effect remained during their second meal and lasted hours after.”1 He went on to explain that he believes the fermentation process likely changes the starches in the nature of the bread, making it more slowly and evenly digested, preventing spikes in insulin.

In simple terms, their study suggests that eating a slice of toasted sourdough bread with breakfast may make a big difference in hunger control all day. Graham, a scientist specializing in the study of carbohydrates at the  University of Guelph in Ontario discovered that “one of the surprising things in our work is that whole-wheat products turned out to have the least healthy responses of all, and this is not what we expected,”he said in an interview.

Continuing he said, “Using white, whole wheat, whole wheat with barley and sourdough white breads, Graham and his team of researchers examined how subjects responded after eating the bread for breakfast and again just hours after eating a standard lunch.” They “showed the most positive body responses after eating sourdough white bread. Those positive responses remained even after eating a second meal that didn’t include bread.”3


What flour you choose to make your sourdough bread with play a role in weight loss too. Whole-wheat flour, for example, contains 12.8 grams of fiber per cup, while white all-purpose flour contains 3.4 grams per cup. Eating more fiber adds bulk to your diet but not calories. That means eating a fiber-rich meal will help make you feel more and more quickly than a low fiber meal. Whole-wheat flour is lower in calories than white flour. It is also higher in protein. Together all of these increase the feeling of satiety, helping you control appetite and calorie intake.

Dr. David Katz, Director of the Prevention Research Center at Yale University School of Medicine, agreed saying that sourdough is “the best bread for your weight loss program… A high-fiber diet reduces your body’s production of insulin and smoothes out blood sugar levels. Which helps you feel full longer, cuts back on cravings, and makes you less likely to overeat. The fermentation process makes sourdough act like it’s got more fiber than any other bread. Volunteers in a recent study who ate sourdough for breakfast had the lowest and most stable blood-sugar levels all day.”4 

He also suggested that with that sourdough toast in the morning, the best breakfast would include eggs or cereal “with the words ‘whole grains.’ Make sure it also contains at least two grams of fiber per serving, and no high fructose corn syrup or partially-hydrogenated oils.5

In a post on his LinkedIn site,  Katz also wrote, “Fundamentally, then, this study suggests that the best way to lose weight and improve health with diet is not by fixating on macronutrients or calories, but by eating wholesome foods in some sensible combination and emphasizing whole, minimally processed plant foods. The study also indicates that the fundamentals of generally healthful eating pertain to us all, regardless of our genes or insulin levels.”6 


These are all interesting findings, but there may more at play here too as Martha Levie explained in a recent post.  For example, she said that commercial bread rises so quickly that many irritants are left sitting in your gut. And because commercial yeast and bacteria do not have time to break down the starches in the bread, “It will spike your blood sugar. That’s why diabetics …can’t eat bread because it spikes their blood sugar; it is because of this yeast.

“The yeast, in and of itself, also can sit in your gut and grow,” she continued. During baking, as the yeast is heated, it releases “spores right before it dies and the spores …get in your gut and grow—you’ve got this yeast in there that sends all these messages to your brain that they want sugar, more and more, and more sugar.” That is a message most dieters do not need.


White all-purpose flour is nearly all carbohydrates, with germ and bran removed and nearly seventy percent of the vitamins, minerals, and fiber). Removing these extends the shelf life of flour but then to make it white, it’s bleached. “Typically, all-purpose flours are bleached with either benzoyl peroxide or chlorine gas.”7

One common additive to bread is high-fructose corn syrup, but there are many other ingredients in bread (or in the things used to make bread) that we as consumers don’t always see on the food’s labels. Some brown bread is colored with caramel coloring and while it may contain some whole grain flour, most of it will be refined white flour. Such bread is high on the glycemic index and will give a “sugar rush” to dieters they do not need.

Here is an example of one loaf on the shelf at Walmart: “Bleached Flour (Bromated Wheat Flour, Malted Barley Flour, Flour, Niacin, Iron, Potassium Bromate, Thiamine, Riboflavin, Folic Acid), Water, Base (Salt, Vegetable Oil, Shortening (Partially Hydrogenated Soybean, Cottonseed And/Or Canola Oil), Dextrose, Sugar, Soy Flour, Cornstarch, Dough Conditioners (Vegetable Mono And Diglycerides, Ascorbic Acid, L-Cysteine, Fungal Amylase), Yeast, Calcium Propionate.”

That sounds more like a chemistry experiment than food to me, but if you must buy bread from a store take this advice from Andrea Donsky:

  • “Look for the term, ‘100% whole wheat’ or ‘100% whole grain’ to be listed as the first ingredient. Simply looking for the word ‘Unbleached’ is not enough as it indicates that the flour has not undergone a bleaching process, but it is still refined.
  • “Bleached flour has been treated with chemicals that could lead to adverse health effects, including diabetes. These and other chemicals in bread may not be listed on the label, so your safest bet is to avoid any foods made with white flour.
  • “Avoid bread that lists artificial additives in the ingredients list.”

“Sourdough fermentation can modify healthiness of cereal [grains] in a number of ways: it can improve texture and palatability of whole-grain, fiber-rich or gluten-free products, stabilize or increase levels of various bioactive compounds, retard starch bioavailability (low glycemic index products) and improve mineral bioavailability.” Potential of sourdough for healthier cereal products” Trends in Food Science & Technology, Volume 16, Issues 1–3, January–March 2005,


The folks at Healthline summarized why sourdough bread is one of the most healthy kinds of bread:

“Although sourdough bread is often made from the same flour as other types of bread, the fermentation process improves its nutrition profile in several ways… [it] contains higher levels of folate and antioxidants than other bread. Also, its lower phytate levels allow your body to absorb the nutrients it contains more easily… Sourdough bread contains lower amounts of gluten and its prebiotic- and probiotic-like properties may help improve digestion.”9

Real, genuine sourdough bread only uses three perfect ingredients: flour, water, and salt. I like that simple recipe, but there is so much more going on that may help you with your journey to weight loss along with so many other health benefits.

Tell us what you think in the comment section below.


1 MofidiFerraroStewartTulkRobinsonDuncan, and Graham, “The Acute Impact of Ingestion of Sourdough and Whole-Grain Breads on Blood Glucose, Insulin, and Incretins in Overweight and Obese Men,” , FEB 28, 2012
2–3 News Staff, “Rising Evidence For Sourdough Bread And Weight Loss,” CityNews, JUL 21, 2008
4–5  Intelligence for Life, “Surprising Weight Loss Tips,” Tesh.com

6 David L. Katz, Director, Yale University Prevention Research CenterGriffin Hospital “Horse Sense for Weight Loss,” Bleached vs. Unbleached Flour, Cooks Country
Andrea DonskyScary Commercial Bread Ingredients You Should Watch Out For, Naturally Savvy
Why Sourdough Bread Is One of the Healthiest Breads

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1 comment

Delicious bread, which will satisfy all your cravings. After trying it once a couple weeks ago, I had to go back and get more this week.

Linda W

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