The basic principle for any season, to choose either fruit or vegetable is, pick the cheapest one which r available in abundance.Mother nature has gifted us with fruits and vegetables which suits to our requirement of that season.For example fruits of winters like amla(Indian gooseberry),orange etc r rich in vit-C to protect us from catching cold.However in summer fruits like watermelon ,muskmelon,cucumber protects us from heat. Since in winter our metabolism is high we can have vegetables like cauliflower,cabbage,peas etc.. which r difficult to digest.Whereas in summer we get bottle guard(lauki), ridge gourd (tori)etc which r easy to digest bcoz our metabolism is slower in summers.So bow to mother nature and try to include seasonal fruits and vegetables in your diet.