Tight clothing can be one cause but the general description of the condition's cause is compression of the lateral femoral cutaneous nerve as it passes underneath the inguinal ligament. (For all you guys out there, that is the ligament under which protrusion of abdominal tissue creates a hernia in the groin - "turn your head and cough" test). The extra tissue of obesity can cause this compression, but even fit individuals can experience this condition from pressure on the nerve from the saddle of a bicycle when cycling for extended periods of time, it can even be a transitory condition experienced during pregnancy.

If you are not wearing tight clothing now, presumably the issue is excess weight. So, you are correct, losing weight can presumably relieve this compression. You need to talk to a good dietician to help you come up with an appropriate diet that will be satisfying and set you up for successful weight loss by taking in the an appropriate amount of healthy calories. Use of NSAIDs or other prescription medications to relieve pain and swelling while you are working on your weight loss through exercise can help, but you should have physician advice and participation here.

As for a good exercise regimen to follow, I would suggest getting involved in a good pool exercise program for persons with your level of excess weight. Exercising in water helps relieve the stress on joints and pressure via gravity and provides good resistance to movement (walking, running, and swimming). The YMCA in Auburn has a pool with a floor that can be raised and lowered and is adjusted for water therapy exercise classes to put participants in an optimum depth for the class involved. I am sure there other such facilities around.

Get involved in a local group of folks working on weight loss so you have some support in your efforts. Celebrate the small improvements and steel your resolve to stay committed - it is a long journey and takes time. Good luck!