Keeping fast during Navratri is said to be very beneficial not only from religious point of view but also from scientific point of view. If you are consuming only fruits during the entire fast, then definitely take seasonal fruits like banana, apple, orange, pomegranate. Instead of sugar, use jaggery, dates or honey in milk.
Although pregnant women are not advised to keep fast, but many pregnant women also observe fast on Maha Ashtami, in such a situation, along with consuming fruits, they must drink coconut water at least three times a day.
It is very important to keep yourself hydrated during fasting. Therefore, drink adequate amount of water to stay healthy. You will not feel weakness if you remain hydrated.
To maintain energy during the fast, you must consume dry fruits. Many nutrients are found in nuts. To get better results, soak dry fruits before eating. This is more healthy.
After the puja, you can eat roasted makhana with almonds and milk along with coconut water, cheese whether raw or lightly fried. You can also eat makhana kheer.
During the fast, consume sago kheer and fruits during the day; for milk shake, make banana shake.
Staying on an empty stomach for too long can also cause gas problems, so keep eating something at regular intervals. Like cucumber or a bowl of curd or fruit salad.
Some people eat food with rock salt during this period, then you should eat boiled potato tikki, sago khichdi, sago tikki made with vegetables and curd. Sweet potato chaat, paneer and buckwheat flour cheela are also good options.