Final answer:
Rakesh restricts his father's diet by limiting refined carbohydrates to help manage blood sugar levels because his father has diabetes and such carbohydrates can lead to rapid spikes in blood sugar.
Step-by-step explanation:
Rakesh restricts his father's diet by limiting the intake of refined carbohydrates such as white bread and rice. This is because these simple carbohydrates are quickly broken down into glucose during digestion, leading to rapid spikes in blood sugar levels. For people like Mohinder's father, who have diabetes, maintaining blood sugar at a safe level is crucial, and consuming refined carbohydrates can be particularly problematic.
Moreover, avoiding refined carbohydrates may reduce the risk of developing diabetes, which is a concern for Mohinder due to the increased risk from obesity and family history. Therefore, Rakesh aims to maintain his father's health by being mindful of the diet, focusing on reducing refined carbohydrates, and possibly incorporating more complex carbohydrates, which take longer to digest and may help regulate blood sugar levels more effectively.