Final answer:
The described features match those of a toddler around two to three years old. Children in middle childhood grow steadily, increasing their height and weight, with average gains of about 7 pounds and 2.3 inches per year. Distinctions between healthy growth and obesity should be monitored through BMI percentiles.
Step-by-step explanation:
The description provided, which includes features such as being chubby, having a potbelly, and a large head relative to body size, is characteristic of a toddler, particularly around the age of two to three years old. During these years, toddlers often exhibit a protruding abdomen due to the typical posture and body proportions at this stage of development. The head size is also proportionally larger compared to the body, as it is a holdover from infancy when the head comprises a more significant fraction of body length.
Addressing the specifics of growth, children in their middle childhood and pre-adolescence continue to grow in height and weight but at a steady, gradual pace. The average yearly weight gain is roughly 7 pounds, with a height increase of about 2.3 inches. There is less distinction between the sexes in terms of body size until the onset of puberty. Additionally, during middle childhood, an increase in muscle mass contributes to weight gain.
If a toddler weighs 20 pounds at one year, by age three, they would likely weigh around 25 pounds, given the average weight gain mentioned; option B would be the most likely estimate.
It's important to distinguish between healthy growth and obesity in children. Childhood obesity is defined by a BMI greater than the 95th percentile compared to reference values for children of the same age, creating concern due to the associated health risks like type 2 diabetes and heart disease.