It's an algorithm that learns your metabolism in respect to your stats and makes adjustments based on those and your specific goal. Has 3 weight loss settings, 3 weight gain settings, 3 reverse diet settings, and a maintenance setting. It goes by macros primarily, calorie intake is just a reference point. It has a tracking app of the same namesake that syncs with the platform in real time. Also tracks fiber intake. I've used it with consistent success. It's easy peasy.