Five-tesla static magnetic fields suppress food and water consumption and weight gain in mice

In this study, the effects of 5-tesla (T) static magnetic fields (SMFs) on food and water intake in BALB/c mice were examined. We also examined body weight changes, organ weights and some serum biochemical parameters to evaluate the physiological changes resulting from changes in food and water intake. Mice were exposed to 5-T SMFs for 24 h and 48 h. Food intake, water intake and the mean body weight of mice tended to decrease after 24 h of exposure to SMFs (p = 0.054, p = 0.119, p = 0.107, respectively). Those parameters decreased significantly after 48 h of exposure (p = 0.039, p = 0.0003, p = 0.009, respectively). These results suggested a positive relationship between the duration of exposure, and the responses, represented by food intake, water intake, and body weight of the mice. However, the weights of brain, lungs, heart, liver, spleen, and kidneys did not change after 48 h of exposure. The blood urea nitrogen (BUN) levels and blood glucose levels increased significantly after 48 h of exposure (p = 0.03, p = 0.005, respectively). The BUN-to-creatinine (BUN/Cr) ratio tended to increase after 48 h of exposure (p = 0.07). We conclude that exposure to 5-T SMFs for 48 h suppresses eating and drinking behavior. We considered that the decreased body weight, increased BUN levels and slightly increased BUN/Cr ratio after 48 h of exposure to 5-T SMFs were due to body fluid loss resulting from decreased food and water intake.