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
Recipe
Geoff’s Brisket
12-13 lb brisket preferred
Rub of your choice (I prefer kosher salt and coarse ground pepper)
Apple juice (optional)
Squeeze Butter (optional)
Heavy duty aluminum foil or butcher paper. (I’m really liking the butcher paper better than foil these days)
Good Thermometers
The night before:
Trim fat cap to ¼” as well as remove any heavy white chunk fat on the top and where the point meets the flat. Square off flat end as well so it cooks more evenly. The trimmed fat can be made into tallow.
Apply GENEROUS amounts of rub all over starting on the fat cap side and finishing with the meat side up. If doing kosher salt and black pepper, do the salt FIRST liberally, pat it in and top that with heavy pepper …more than liberally. Pepper on top of salt…..always
Place in fridge wrapped in cling wrap and let sit until ready to be put on smoker. I usually do this the night before and smoke the next AM, but the brisket can be put on immediately after rubbing as well if needed. Your smoke ring will pop a little more if you let it sit overnight.
Day of:
Place on smoker at 250 degrees. I prefer fat down to protect the meat from heat from the bottom and the grate doesn’t mess up your bark on the meat side. Either is ok. I put my temperature probes in the thickest part of the meat at this time. (I have a remote temp sensor for both the meat and smoker temps, I highly recommend them)
Spritz with apple juice every two hours (if you choose to)
Don’t open the smoker a lot because “if you are lookin’ you ain’t cookin’…”
Foil or butcher paper wrap at 160-165 internal temp if bark looks right or at the stall…. whichever comes first. If bark needs a little more time then take it to 170. If using the squeeze butter, put it on the brisket liberally then close up foil and put back on smoker.
Continue to 203 deg …. (total cook time “guideline” is 1.00 - 1.5 hours per pound for completion…but go by internal temp for actual). (if you want to chop the whole thing, I would take it to 205 no matter what.)
Pull off smoker and set in cooler still wrapped covered in a towel or in a cool oven still foiled to rest for 1-2 hours before slicing. One hour minimum so that the briskets moisture that was forced outward in cooking can re- distribute while cooling slowly.
Slice the flat for sliced brisket (AGAINST THE GRAIN OF THE MEAT) and you can either slice (against the grain) or chop the point …. Enjoy!
Some thoughts on probing and done-ness….
Monitoring needs to be in the center of the thickest part of the flat ... I like to angle it in to get more of the probe in the meat without passing through the other side I have had to change the location of the probe as well after my target temp was reached because it wasn't right.. ie the probe says 200 but it's still tough and I find the real center is still at 190-195..
This is what works for me. I am not a pro....Just a backyard hack.
I take it to 200 with the monitoring probe. When you reach that temp, I like to take a handheld insta-read thermo like a Thermopop or Lavatools Insta-read and check other areas of the meat for their temp as well just to see how it is going. While doing that I am probing the brisket for tenderness. The probe or knife even needs to pass through all areas of the meat like a hot knife through butter...and if it doesn't....keep taking that center up another couple of degrees. Check at 202...then 204 if need be. 200 is not a magic catch all number for me. It is just a number for me to start probing. Luckily it usually is done at 200-203 but I have had to take it further like described above.
Personally, I’ve rarely had a brisket done under 200 and I've messed up my share taking them off before. The ones I have pulled at 195 or less due to time constraints are like many experience…..dry and tough. It's done when it's done....not before.” A dry tough brisket is an underdone brisket….not an over-cooked brisket. Underdone does not allow the collagen and connective tissues to properly break down and become moisture and subsequently tender.
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