Bread-Borne Obesity

Investigating common health advice in-depth drives us to better answers and equips us with better recommendations for our patients. In this case, knowing that so many people across the world believe that eating bread leads to weight gain, we ask two important questions. First, is it true? Second, why is it true? Before we tell our patients or the public to cut down on bread, we want to be sure that it really is driving weight gain. We also want to confirm the mechanism so we can best mitigate the effects.

The Obesity Epidemic and Its Causes

As the epidemic of obesity continues to contribute to the multitude of cardiovascular, metabolic, and other chronic illnesses, it’s critical to know for sure how different foods contribute to the problem. Some blame high fat diets. Some blame willpower. Some blame processed foods. Some blame toxins. And some will blame bread and carbs, after reading this article. In reality, the factors vary from person to person, but today’s study teases out whether bread or its flour could be contributing to the epidemic.

Study Design

Enlisting some lab mice, scientists set up different groups and fed them different diets. The groups include the following: mice fed “Chow, Chow + Bread, Chow + Wheat flour, Chow + Rice flour, High-fat diet (HFD) + Chow, and HFD + Wheat flour.” They then tracked the mice in terms of weight, energy expenditure, liver gene expression, and blood metabolites.

Wheat Gained More Weight

While the calories consumed by the mice did not vary between groups very much, the groups on wheat flour and rice flour gained more weight than those on high fat diets or chow. When given choices, the mice ate more of the flours, but the difference was not enough, in calories, to account for the weight gain. While the weight gain was not directly correlated to the calories, after measuring energy expenditure, the researchers concluded that a slower metabolism was to blame.

When they measured the gas exchange rates of the mice on different food plans, those eating more carbs like wheat and flour demonstrated slower metabolic rates. Thus, they had more calories left to store as fat. Measurements of fatty acids in their blood stream also demonstrated that they were making more fat, and their livers showed increased fat storage. When the wheat flour was removed, these changed shifted back quickly, though the study does not give precise numbers here.

What to Do Now

While further research is needed to prove how much of an impact this has in humans, it does suggest we moderate mow many bread-like carbs we include in our diets. At the very least, we should watch our cravings for carbs and keep a balanced whole food diet as the starting point. Pursuing a healthier, more abundant diet requires knowledge and willpower.

 

Links to Other Articles at SFM.org:

What’s The Deal With Einkhorn?

Hidden Factors of Metabolic Health

Mind Blowing Connections Between Autoimmune disease and Metabolic Disease

Original Article:

Shigenobu Matsumura, Miona Marutani, Eri Nousou, Nagisa Murakami, Saki Mizobata, Miyu Fujisawa, Mizuki Fujiwara, Nanase Iki, Soyoka Horie, Yuka Yamato, Azumi Yamamoto, Mina Fujitani, Teppei Fujikawa, Chinami Ishibashi, Shigeo Takenaka. Wheat Flour Intake Promotes Weight Gain and Metabolic Changes in Mice. Molecular Nutrition, 2026; 70 (2) DOI: 10.1002/mnfr.70394

Thanks to Science Daily:

Osaka Metropolitan University. “Scientists discover why bread can cause weight gain without extra calories.” ScienceDaily. ScienceDaily, 14 April 2026. <www.sciencedaily.com/releases/2026/04/260414075637.htm>.

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Sanctuary Functional Medicine, under the direction of Dr Eric Potter, IFMCP MD, provides functional medicine services to Nashville, Middle Tennessee and beyond. We frequently treat patients from Kentucky, Alabama, Mississippi, Georgia, Ohio, Indiana, and more... offering the hope of healthier more abundant lives to those with chronic illness.