To eat and what not to eat

GF

Help! I've got books and the guide from doctor but sometimes I'm out and about and have nothing with me as a guide. So I use Google (though my doctor says ignore). Are ALL fruits and vegetables fine or some aren't? Like today I bought a fruit bowl with watermelon, honeydew and cantaloupe. I Googled to be sure and says cantaloupe/honeydew are fine but I got conflicting answers on watermelon...one said yes, one said no. Why can't there be consistency in regards to this stuff??