This document describes a weight loss and fitness program called The Challenge. It works by having participants set a goal, select a challenge kit containing meal replacement shakes or snacks, and join a challenge group for community support and accountability. Participants track their progress using an app and can win cash and prizes. The program has already helped over 3 million people lose weight and has donated over $100 million to charity. It is supported by a scientific advisory board and uses high quality ingredients and manufacturing standards.