Some people think it would be better to our environment and economy if people only ate locally produced food. Do advantages outweigh disadvantages?

It is believed by some that consuming domestic food would be beneficial to environment and economy. In my opinion, boosting economy and curbing pollution are advantages which hold more weight, while disadvantages cannot be overlooked.
On the one hand, the main advantage of having local food is that it would help economy growth. To explain, were people to eat the food of only particular locality, it would generate income for the producers and they would not need to import food from foreign countries. Therefore, the production and the marketing would be within national boundaries, fostering the economy.
Another evident benefit is that locally grown food would reduce food miles since imported food arrives at supermarkets from hundreds or even thousands miles. This includes transportation by cargo ships or aeroplanes which pollute the environment, so with enough yield of inland food, importation of foreign food would be no longer required and it would ameliorate the environment.
On the other hand, the primary drawback of eating only local food is that people would be deprived of exotic fruits and vegetables which are only available in foreign nations. For example, a Kiwi fruit is generally grown in New Zealand and Italy, whereas other countries import this fruit because they do not have desirable weather conditions. Hence, these countries would lose a variety of produces if the natives only take local food.
In conclusion, although ingesting only local food would result in loss of diversity of food, I believe that its merits are more than its demerits.