Final answer:
Some people become over or underweight due to genetic factors, lack of interest in food, and other factors such as socioeconomic status and metabolism.
Step-by-step explanation:
Some people become over or underweight despite the presence of a biological regulatory system for controlling energy balance due to various factors:
- Genetic factors: Genetics can influence obesity. Many obese people come from families with overweight parents. Scientists have identified genes that may contribute to obesity.
- Lack of interest in food: Some people may have a lack of interest in food, resulting in underweight.
- Other factors: Factors like socioeconomic status, physical environment, inactivity, metabolism, and body's set point can also contribute to weight imbalance.