eating ( lack there of)

My 3 yr old lately has become very finicky about meals. He's not generally picky about what he eats. He is a major fruit and veggie kid, and refuses to eat meats of any kind ( even hotdogs, do you believe it)  He seems to only want to eat cucumbers. That's all, he'll sit there and eat 3 of them if I let him. My question,
1. Is it normal for a child to NOT  want to  eat??
2. How much nutrients are really in a cucumber

[Renee Radenberg]

His weight and height is above the 95th percentile for his age. At that age some children become picky eaters and eat only certain foods. You are lucky he is eating fruit and vegetables. Those foods are usually the foods 'picky eaters' do not like. Fruit and vegetables have all the vitamins and minerals we need accept very little protein. He needs to eat protein sources such as dairy foods (cheeses, yogurt, milk, pudding, and ice cream), or non dairy (soy milk, soy yogurt, soy ice cream). You can add nuts, seeds, or beans to his vegetables or starches which will give him complete proteins when combined, such as peanut butter and whole fruit jelly sandwich. Hoped this helped you.