Final answer:
Eating while doing homework is a factor that can increase the likelihood of a child gaining unhealthy weight, as it may lead to consuming excess calories without mindfulness. This behavior should be monitored and modified alongside promoting regular physical activity and a balanced diet to prevent childhood obesity.
Step-by-step explanation:
The factor in a child's life that increases the likelihood of unhealthy weight gain is b. Eating while doing homework. This behavior can lead to mindless eating, where the child may consume more calories than needed, often in the form of high-calorie, low-nutrient snacks, contributing to an energy imbalance and potential weight gain. In contrast, eating regular meals (option c) can help maintain a healthy weight by providing structure and balance to a child's diet. Childhood obesity is a concerning condition defined as body weight at least 20 percent higher than a healthy weight for a child of that height (option c), and can lead to several health issues if not addressed. It is important to encourage a combination of physical activity and healthy eating as fundamental parts of a child's education to combat obesity (option d).