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
Enjoyed the conversation last night. I forgot the cord for the laptop, and it dropped from 30% to zero unexpectedly. Apologies for the abrupt exit.
I thought about 'carnivores lying' for a stretch last night afterwards. Did they mean carnivores are lying in general about the positives of carnivore? Did they mean the individual carnivores are lying about their personal health? Good conversation on the topic.
Like said from the beginning, going into carnivore I had no idea of the health benefits other than from the weight loss. On the day I started carnivore was nothing more than another weight loss hack, the latest in the yo-yo dieting approach. I was going to drop 15-20 pounds (if it actually worked) and then go back to eating like normal people. I had already lost 10-12 pounds before I watched my first video or read my first article about carnivore. The weight came off so fast (averaged about a pound per day the first thirty days) when I was asked if I thought it was healthy to just eat meat and drink water I pretty much said, " I don't know, but the weight is falling off so I'm going to roll with it for now". I started reading and watching videos and one of the first videos that popped up was by Cabana Chronicles and her using carnivore for her MS. My autoimmune disease is really similar and that triggered me to watch a ton of videos that evening. Over the next few days I was in constant research mode.
I never used the term lying but I was skeptical, even a nay-sayer, about the results people were sharing. As soon as I would start seeing the light (LOL) they would ask me to subscribe, or hit the LIKE button, or buy this product, and that became the catch/the automatic disconnect.
I was on gabapentin/Neurontin and prednisone for pain and inflammation and there is no way those can be replaced with a rib eye. As Mrs. Cabana Chronicles talked about not taking medicine I was waiting for the hook, "what is for sale today?". Then it sort of dawned on me that I had come off my long stretch of nights (six 12-13 hours shifts) and I didn't take the medicine for pain and inflammation. I immediately tagged it as a coincidence. The following week I pulled my four shifts and then two more slots of overtime and no medicine during or after the six shifts. Then there was third week and (I'm sort of slow) it started to resonate that there may actually be a connection to carnivore and inflammation. I think my first true lesson in carnivore was that it is not the rib eye nearly as much as it is the elimination of the carbs and sugars.
Withing 5-6 weeks of eating strict carnivore (other than the drink mixers to help with drinking water) I was off medicine I had been on for six years. From there I was 'curious' maybe even 'intrigued' by the effects of the elimination diet. I scheduled blood work, both my regular blood work for NMO/SD and my HAZMAT physicals for work. I staggered them to get bloodwork every 3 months or so to check my immunoglobulin numbers. Within three months on carnivore the lower numbers were inching up and the higher numbers were inching down. After 12 months as a strict carnivore my immunoglobulin numbers have returned to what is considered normal. I have one number that is just a few points high but nothing like the previous six years.
When the post was made about lying I wonder if it is suggesting I am one of the people lying about my individual successes. I am no longer taking medicine for pain nor inflammation. I have lost between 90-95 pounds. My energy levels are not super human but they have returned to levels that I had as a much younger man but coupled with regular fasting (longer fasting 72 to 96 hours) the energy levels are super crazy high. Do people think I only lost 75 pounds and exaggerated my claims so it sounds better? Do I secretly take medicine and just claim I do not?
I get it. I was that guy too. I was skeptical/didn't believe from the very beginning. Carnivore was just another weight loss hack, nothing more/nothing less. It was the same as any other hack that used large weight loss as click bait to get me to buy something.
I would never use the term 'lying' but I can see where I came from that same sentiment for a stretch. If you look at each of our stories, how far we have come, I won't say we have all experienced miracles, but I will say for me, I've headed down that path.
Sometimes, stories like these are hard to believe.
babbling, waiting for the gym to open. Great conversation last night. Enjoyed it.
Scott