You may or may not need to lose weight. You could be the ideal size and weight and still be engaging in unhealthy behaviors and habits. If you do need to lose weight, realize that that is only one part of the healthy equation, although it's a great place to start.
Most of us know what we need to do; we just don't do it for one reason or another. There's very little new information we need to know in order to get on the pathway to better health and most answers to health questions are readily available either online or off. So if you know what to do, yet are not doing it, you simply need to GET MOTIVATED!
WHAT'S YOUR EXCUSE??