Why is the account linking feature useful?

The main benefits of linking your account with other users are:

1. Motivation – sharing your journey means you can encourage and motivate each other.
2. Accountability – knowing someone can see your diary is an incentive to make sure you've used it and made good choices.
3. Inspiration – seeing others' interesting meals and workouts give you fresh ideas.

All of the above have the benefit of helping to keep you more engaged with the app, and the more you use your diary, the more effective it is in achieving your goals.