One pound of body fat is approximately equal to 3,500 calories. This standard estimate indicates that to lose weight, a caloric deficit of 3,500 calories must be achieved, either through diet, exercise, or a combination of both. Understanding this relationship can help people set realistic weight loss goals and develop effective strategies for achieving them. It's important to approach this with a focus on sustainable habits, rather than extreme calorie-cutting, to maintain health during weight loss efforts.