Too little stomach acid can lead to a vitamin B-12 deficiency, which can cause dementia. When people were randomly assigned to imagine that they were going to order a cold—rather than hot—sandwich, they were more likely to also imagine ordering chips or a soda. Heard that dairy foods raise the risk of breast cancer? Relax. If you’re sitting for hours at a time, even 2 minutes of light exercise every 20 minutes or so can help keep a lid on blood sugar after a meal.