Scientists Reveal Why Bread Can Cause Weight Gain Without Overeating17 April 2026 ByDavid Nield (Photographer Basak Gurbuz Derman/Moment/Getty Images) New research in mice shows how eating bread can cause body weight and fat mass to increase, even though caloric intake stays at a similar level. The research, led by a team from Osaka Metropolitan University in Japan, highlights how carbohydrates can contribute to weight gain as well as excessive fat intake – which is what dietary advice tends to focus on. This isn't the first time nutritionists have talked about bread and carbohydrates and their contribution to weight gain, but there hasn't been much detailed research into the relationship – especially wheat flour – or into what might be happening at a metabolic level. The team discovered that eating more wheat bread was associated with reduced energy expenditure, pushing the metabolism towards a state where fat storage is prioritized, even when the calories in a diet stay at a similar level. The researchers analyzed the difference that bread in the diets of mice had on their weight (A) and fat tissue (B, C). (Matsumura et al., Mol. Nutr. Food Res., 2026) "These findings suggest that weight gain may not be due to wheat-specific effects, but rather to a strong preference for carbohydrates and the associated metabolic changes," says nutritionist Shigenobu Matsumura of Osaka Metropolitan University. The researchers set up experiments in which lab mice were given a choice between their normal, healthy cereal-based diet and either simple bread, baked wheat flour, or baked rice flour. The mice were then monitored to check their weight and how their bodies burned calories at rest and when active. Using blood samples, the study team also examined hormone, blood sugar, and metabolite levels in the animals, while post-experiment tissue analyses assessed gene expression in the liver. The experiments showed that the mice strongly preferred to switch from their standard diet to carbohydrate-heavy snacks, which then led to weight gain and more fat tissue in the mice, particularly in the males. Further analysis and follow-up tests suggested that these two key changes were being driven not by overeating or a lack of exercise, but by the foods themselves. In the wheat flour diet, fewer calories were being burned overall, while genes responsible for turning carbohydrates into fat were activated. Another follow-up test focusing on the wheat flour group showed that when the chow diet was restored, the weight gain stopped, and the metabolic shifts were reversed. "In the future, we hope this will serve as a scientific foundation for achieving a balance between 'taste' and 'health' in the fields of nutritional guidance, food education, and food development," says Matsumura. The findings are more evidence of how what we eat can cause changes in how our body processes food and burns the calories it contains. In the case of bread, it seems to slow down the body's metabolic engine. One limitation of the study is that it used mouse models, rather than human volunteers. While it's likely that similar processes are happening in people, it's not certain – so that's something future studies can pick up. The researchers also want to experiment with a broader selection of foods to identify what exactly it is about bread that causes this reaction. No diet study like this exists in isolation, of course. We know that a variety of other factors can also impact how our metabolism reacts to food and drink, including age and hormone-related changes. Related: There's a Surprising Link Between a Key Nutrient, Obesity, And Alzheimer's Risk Further research should help establish the role that wheat and bread can play in a diet and how the simple "calories in, calories out" rule isn't always straightforward. "Going forward, we plan to shift our research focus to humans to verify the extent to which the metabolic changes identified in this study apply to actual dietary habits," says Matsumura. "We also intend to investigate how factors such as whole grains, unrefined grains, and foods rich in dietary fiber, as well as their combinations with proteins and fats, food processing methods, and timing of consumption, affect metabolic responses to carbohydrate intake." The research has been published in Molecular Nutrition & Food Research. ARTICLE SOURCE: https://www.sciencealert.com/scientists-reveal-why-bread-can-cause-weight-gain-without-overeating
How To “Red-Pill” Your Friends & Family About Radical Health
Radical Health Newsletter #142
You know that scene in The Matrix where Neo takes the red pill... and his whole reality shifts?
That's what discovering this whole radical health thing feels like.
And just like Morpheus, you probably want to offer that same "red pill moment" to everyone you care about.
When your friend tries animal-based
But here's the thing...
Nobody likes being preached to about their food choices.
(Especially by that crazy friend who won't shut up about seed oils 😅)
And we get it - you’ve found something that changed your life. You feel better than you have in years, and it’s only natural to want the same for the people you love.
But when they look at you standing barefoot in the sun, drinking raw milk and eating organs… they just see ‘that person.’
You know the type… the one who brings their own butter to restaurants.
Who says things like “circadian rhythm” in casual conversation.
Who gets more excited about cast-iron pans than the latest Netflix show.
Yeah, that might be us.
So here's how to actually wake people up:
#1 LET THEM NOTICE
Don't say a word.
Let your 2pm energy do the talking.
Be suspiciously happy during winter.
Wait for the "You look different..." comments = Priceless
#2 PLANT TINY SEEDS
"Just made some simple changes..."
Did you know that avoiding the sun is about as likely to kill you as smoking cigarettes? (share this study with them)
(The curious ones will bite)
#3 SHARE RESULTS, NOT LECTURES
Your performance in the gym
Your pharmaceutical-free life
Be that annoying person who actually enjoys Monday mornings
#4 DROP TRUTH BOMBS CASUALLY
Isn’t it weird how the doctor said my autoimmune condition could never be cured, but then it completely went away when I changed my diet?
Strange how our great-grandparents cooked meat and organs in tallow but had no heart-disease…
Did you hear about the study in the BMJ that found exercise was 1.5x more effective at treating depression, anxiety and stress than medications? Pretty wild!
#5 LET THEM CONNECT DOTS
Share one of our newsletters (this is a good one for newbies)
Show your bloodwork
Make them question why you never get hangry anymore
#6 GUIDE, DON'T PUSH
Make it about THEM feeling good, not YOU being right
Start them small (Pure American Liver is a lot easier to start with than raw liver 😂)
Remember: You were once skeptical too
We don’t win people over with arguments. We win them with curiosity. With energy that won’t quit. With overflowing grocery carts full of raw milk and grass-fed butter. We show them that this “crazy” lifestyle works - because we live it.
The system spent billions programming people.
Don't expect to undo it in one conversation.
Just plant seeds. Water them with results.
Be patient and watch what happens.
To you (and your loved ones) radical health,
Heart & Soil
Paul Saladino