Unless every movement made, food eaten and drink consumed is logged, the recommendations for how much and what kind of food should be eaten will be off.
When a recipe is found on the web it can be imported it into the app by entering the URL. MyFitnessPal will estimate ingredients and show calorie, fat, protein, carbohydrate breakdown.
You can post updates on progress and have other people comment on it, encouraging to keep working out. You can ask questions and a community of more than 1 million users will be there to answer.
Earn points, unlock achievements, take on challenges and quests and level up. Seeing progress, getting rewarded for activities and reaching a set threshold feels nice and helps in continuing to be motivated. Especially when just starting out.
There's even a leaderboard so you can compare your progress to your friends.
There is a paid option ($4.99/mo or $44.99/yr), called Hero, that adds private messaging, ability to challenge a friend in an activity, assign yourself a title and weekly insights among other things.