Final answer:
A stable body weight is achieved through energy balance, where caloric intake is equal to energy output. A positive energy balance leads to weight gain, and a negative energy balance causes weight loss. Maintaining energy balance is essential for achieving and sustaining a stable body weight.
Step-by-step explanation:
The situation that would tend to lead to stable body weight is energy balance, which is when the energy consumed in food is equivalent to the energy expended in metabolism and physical activity. Energy homeostasis is a balance between food intake and energy expenditure, and maintaining this balance is crucial for sustaining a stable body weight. A balanced diet not only provides energy but also supports metabolic reactions vital for good health.
When the energy intake matches the energy used by the body for cellular and physical activities, the net energy change is zero (AU = 0), which leads to stable body weight. A positive energy balance, on the other hand, means that the body is taking in more energy than it is expending, leading to an increase in stored fat and thus an increase in body weight. Conversely, a negative energy balance indicates that the body is using more energy than it is consuming, resulting in the use of stored energy and a decrease in body weight.
Therefore, to maintain a stable body weight, individuals should aim for a balance between the calories they consume and the calories they burn through basic metabolic processes and physical activity.