Which factor is NOT commonly associated with the causes of obesity?

Excessive hydration is not commonly associated with the causes of obesity, making it the correct answer. While hydration is essential for overall health, consuming sufficient fluids is generally not linked to weight gain. In fact, drinking adequate water can sometimes help with weight management by promoting satiety and supporting metabolism.

The other factors mentioned are well-established contributors to obesity. Unhealthy food choices, which often involve high-calorie, low-nutrient foods, can lead to weight gain when consumed in excess. Lack of physical exercise is also a critical factor since physical activity helps burn calories and maintain a healthy weight. Genetics play a significant role as well, as they can influence body composition, metabolism, and the likelihood of weight gain or loss over time.