Around the Mediterranean, people continued in the Islamic period to rely on the three main foods from antiquity. Those were wheat (mostly bread), olive oil, and wine. Though technically Islam did not let you drink alcohol, still a lot of people did drink wine. People who didn’t drink wine started to drink more tea. The Sogdians brought tea to the Islamic world from China.
When the Islamic Empire grew to include northern India, about 750 AD, traders brought back sugar cane to the rest of the Islamic world. Sugar was very popular! Soon people all over the Islamic Empire were eating sugary candy and putting sugar in their tea. A new kind of sorghum reached the Islamic Empire from India too. It quickly became an important new food.
On the other hand, Islam said people couldn’t eat pig meat (pork and ham and bacon), and people really did stop keeping pigs. People were probably already not eating pigs in Egypt and Arabia and along the Mediterranean coast of West Asia. But with the spread of Islam people also stopped eating pigs in the rest of North Africa, in Turkey, Iraq, Iran, in India, and in Afghanistan. People stopped keeping pigs and started keeping more chickens and goats and sheep instead.
People also started to grow and eat more citrus fruits. Citrons and bitter oranges had been available in West Asia for thousands of years already. But it was only around 900 AD that Islamic food scientists bred the two fruits together to get lemons. Lemons quickly became popular all over West Asia. By the 1100s, Egyptian Jews were combining lemon juice and sugar to make lemonade. A few hundred years later, people in West Asia also began to eat sweet oranges, which had mainly been grown in India and China before this time. The addition of lemons and sweet oranges may have helped a lot with getting enough Vitamin C. Before this people had gotten Vitamin C mainly from wine vinegar, onions, and cabbages.
Islamic food scientists working maybe in Iran or Afghanistan also bred purple carrots around 800 AD. Purple carrots quickly became a popular treat all over West Asia, North Africa, and Islamic Spain. Encouraged by their success, scientists then produced red and yellow carrots, which also spread throughout the Islamic world (and beyond).