A modest shift from red and processed meat toward beans may bring measurable health benefits, at least for men.
In the BeanMan study, researchers at the University of Helsinki asked 102 working-age men to change part of their protein intake for six weeks. One group ate the typical amount of red and processed meat for Finnish men, about 760 grams a week or one-quarter of total protein. The other group replaced much of that meat with foods made from peas and faba beans, reducing meat intake to about 200 grams a week, closer to dietary recommendations.
The results, published in the European Journal of Nutrition, showed that the men in the legume group lowered both total and LDL (“bad”) cholesterol and lost an average of one kilo. Men in the meat-only group lost just 300 grams.
“The legume group lost significantly more weight than the meat group. We didn’t encourage the participants to lose weight, but asked them to continue eating as before, apart from consuming the foods we provided,” said study leader Anne-Maria Pajari, professor of molecular nutrition at the University of Helsinki.
Researchers expected improvements in cholesterol, since legumes contain healthier types of fat than processed meats. But the weight loss was a surprise. Pajari noted that participants were told to eat as they normally would, apart from the foods provided.
Importantly, the legume-based diet did not compromise nutrient status. Vitamin B12 intake dropped slightly with lower meat consumption, but levels stayed within a safe range. Iron intake was actually higher in the legume group, and iodine intake showed no difference.
“The legume food products we provided were quick to cook, making them easy to use. We also handed out recipes to encourage cooking,” Pajari said. “Based on our findings, I believe a moderate dietary change towards a more sustainable direction, using peas, beans and lentils, is possible for most of us.”
The researchers concluded that swapping part of weekly red and processed meat intake for legumes may help support cholesterol reduction, diabetes prevention and weight management, while still fitting into a mixed diet.
This study was funded by the Strategic Research Council at the Research Council of Finland. Open access funding was provided by the University of Helsinki (including Helsinki University Central Hospital) and the Helsinki University Library.