An apple a day keeps the doctor away 哪国的谚语？

作者Gregory Y. Titelman在其词典《Random House Dictionary of Popular Proverbs and Sayings》中有这样的说明：
"An apple a day keeps the doctor away. Eating fruit regularly keeps one healthy. First found as a Welsh folk proverb " 'Eat an apple on going to bed,/ And you'll keep the doctor from earning his bread.' First attested in the United States in 1913，An apple a day keeps the doctor away......"
“An apple a day keeps the doctor away. 经常吃苹果可以让人保持健康。最早出现在英国威尔士的谚语中---如果大家睡觉前都能吃一个苹果，我们就会让医生们连面包也买不起了（无法维持生计了）在1913年，美国最先改动了威尔士的谚语，在美国出现了An apple a day keeps the doctor away. ”

他爱上了新搬来的女邻居，可惜她结婚了，老公是个收入不菲的外科医生。但无论雨雪，每天清晨他都记得把一枚新鲜红润的苹果默默留在她门口的蓝色信箱上，直到有天终于还是被她碰上了。望着他的窘迫，她笑了：“这是我遇到过最特别的表白。”他低着头：“An apple a day keeps the doctor away。”

美国的儿歌