Weight management is about long-term success. People who lose weight quickly by crash dieting or other extreme measures usually gain back all (and often more) of the pounds they lost because they haven't changed their habits in a healthy way that they can stick with.
If you are looking for an effective weight loss fitness program, it's wise to look for one that will meet your needs and set you up for long-term success. Intensive diet and lifestyle programs work well for weight loss.
Lifestyle and work habits partially determine how many calories we need to eat each day. Someone whose job involves heavy physical labor will naturally burn more calories in a day than someone who sits at a desk most of the day (a sedentary job).
For people who do not have jobs that require intense physical activity, exercise or increased physical activity can increase the number of calories burned.
For some people, due to inherited genetic factors or other health conditions, the resting metabolic rate (RMR) can be slightly higher or lower than average.
It's also important to follow healthy eating guidelines in general, even after you have lost weight. This should include sufficient amounts of protein, vitamins, and minerals with limited amounts of fat and sugar.