The answer... is yes. Maybe. It starts when you're just a little kid in grade school and continues into adulthood. What are we talking about? Peer Pressure. And it could have a negative impact on your health -- but it's not always your fault. Researchers followed more than 12,000 people over a 32-year-period and discovered that those who had obese friends were 17% more likely to become obese. Here's the science behind friendships and weight gain.