Which of the following is a primary environmental factor affecting weight management?

Diet is a primary environmental factor affecting weight management because it directly influences the number of calories consumed and the nutritional quality of those calories. What individuals eat plays a crucial role in their ability to manage their weight over time. Dietary habits can be shaped by a variety of environmental influences such as cultural food practices, availability of healthy food options, socioeconomic status, and education regarding nutrition.

These dietary behaviors can significantly impact the balance of calories consumed versus calories expended, which is essential for maintaining, losing, or gaining weight. Therefore, an individual's dietary choices and patterns are foundational elements in the overall equation of weight management, making diet a key environmental factor.

In contrast, while genetics, age, and metabolism can influence body weight and composition, they are more related to biological predispositions and metabolic processes rather than environmentally driven factors like diet.