Calorie- and activity-tracking programs like MyFitnessPal aren't perfect, and neither are people.
"You're eating more than you think because you're not counting properly," Fakhoury said. That can foil your weight-loss goals.
For instance, maybe you're logging a cup of broccoli, but not the tablespoon of olive oil you cooked it in. Maybe your bowl of cereal is double the actual serving size.
Or, maybe you've told a calorie counter you're "moderately active," but the app's definition of moderate activity exceeds your own, prompting it to tell you to eat more than you need.