Final answer:
During the second and third trimesters of pregnancy, a pregnant person should aim to gain 0.45 kg (1 lb) per week.
Step-by-step explanation:
During the second and third trimesters of pregnancy, a pregnant person should gain approximately 0.45 kg (1 lb) per week. This weight gain is important for the healthy development of the fetus and is a normal part of pregnancy. However, it's important to note that every individual is different, and weight gain may vary based on factors such as pre-pregnancy weight and overall health.