One really unpleasant side effect of eating too much meat? Urinary tract infections (UTIs). A study from McGill University in Montreal found that grocery-store chicken is often contaminated with a form of E. coli bacteria known to cause UTIs, and what’s worse is that the bacteria is resistant to many of the antibiotics used to treat the condition. The bacteria can live on in your gut and cause problems as much as 6 months after eating the contaminated meat. That doesn’t happen when you eat kale!