Describe the secular trends in physical growth over the past 150 years, including factors that may be responsible for changing trends

What will be an ideal response?

Answer: Over the past 150 years, secular trends in physical growth—changes in body size from one generation to the next—have occurred in industrialized nations. Children are taller and heavier than their parents and grandparents were as children. These trends have been found in Australia, Canada, Japan, New Zealand, the United States, and nearly all European countries. The secular gain appears early in life, increases over childhood and early adolescence, then declines as mature body size is reached. This pattern suggests that the larger size of today's children is mostly due to a faster rate of physical development.
Improved health and nutrition are largely responsible for these growth gains. Secular trends are smaller for low-income children, who have poorer diets and are more likely to suffer from growth-stunting illnesses. And in regions with widespread poverty, famine, and disease, either no secular change or a secular decrease in body size has occurred. In most industrialized nations, the secular gain in height has slowed in recent decades. Weight gain, however, is continuing.