Controlling or losing weight depends on knowing how many calories people consume in relation to how many calories they burn. Tracking burned calories allows people to better determine how many calories they need to eat.
While other factors can affect someone's ability to gain or lose weight, the difference between how many calories they consume compared to how many they burn is the predominant factor; a large enough difference can overcome nearly any medical condition. While it's possible to roughly estimate someone's daily caloric burn based on their weight, age, height and gender, more precise tracking can lead to better results.
People can record their daily activities and estimate how many calories they burn, and smartphone apps and other digital tools can make this process a bit easier. Wearable devices designed as fitness tools can also help; devices that track how quickly the person wearing them is moving can lead to better results for tracking calories burned during exercise.
It's also important to factor in the individual's basal metabolic rate. Even while at rest, the human body burns calories to maintain an appropriate temperature, pump blood and send electrical signals through the nervous system. This rate is difficult to determine precisely, but an estimate based on the person's age, weight, height and gender can be a useful starting point.