Is it possible for an overweight person to easily lose weight without any side effects?

No. It's not easy to lose weight. It's a full time job. It requires motivation, dedication, & self discipline. It can be done but it doesn't happen quickly or by accident. Consider joining weight watchers, tops, curves or buying one of the many excellent books available. Set a target date, take one day at a time, expect backsliding, stay focused, aim for lifelong healthy eating. B patient. Good luck!