Can a person alter what foods their kid will like in the future by consuming them during pregnancy?
What you may not consider is that the foods you eat while pregnant might influence the tastes your child prefers after he is born. A healthy diet throughout your pregnancy supports your unborn baby's growth and development, but when you fill up on junk food, you might shape his preference for unhealthy foods later in life.
Personally, I'm skeptical you can have much control over this during pregnancy - a lot of what their tastes will be form during the first year, and what's important is not specifically what they eat, but whether it is balanced and nutritious. This article has a good list of tips to help infants/toddlers develop good eating habits.
During pregnancy it would be wise to 'feed' your wife exactly what she wants. In all seriousness though, my own observation is that this is a myth. My wife likes all sorts of food that our children wont eat. Also each child has their own preferences even though she ate pretty much the same things throughout both pregnancies.