Some side effects of obesity are more obvious than others. It's easy to avoid stepping on the scale, but it's not as simple to ignore the fact that your clothes are getting tighter. But many of obesity's effects are more subtle—excess weight strains your heart, brain, and other body symptoms in ways that aren't always visible until it's too late. These are some of the secret side effects of obesity scientific studies have found. Read on to find out more—and to ensure your health and the health of others, don't miss these Sure Signs You May Have Already Had COVID . 1 You've Become Diabetic or Pre-Diabetic Obesity can cause you to have an elevated A1C—a test for diabetes and prediabetes that measures your average blood glucose (sugar) level over the last three months. That's not something you'll know unless your doctor tests for it. Not everyone with obesity will have an elevated A1C, but obesity is a major risk factor for diabetes and its neg