Final answer:
Most popular and successful weight loss programs share common principles that include adhering to a low-calorie, low-fat diet, engaging in high levels of physical activity, and following daily routines.
Step-by-step explanation:
The most popular and successful weight loss programs share common principles in common. These principles include adhering to a low-calorie, low-fat diet, engaging in high levels of physical activity, eating breakfast every day, watching fewer than ten hours of television per week, and weighing themselves regularly. Many successful weight loss programs also emphasize the importance of changing both diet and physical activity together, rather than focusing on one without the other.