Oscar definitely shows a preference for sweet foods like fruits. This is natural. Research has shown that babies are born with an inherent liking for sweet foods. Newborns that were given sugar water (prior to bottle feeding or breastfeeding) showed an expression of ‘satisfaction’ accompanied by eager licking of their upper lip and loud sucks. Those given just distilled water remained sleepy and disinterested (Steiner, 1977). It is thought that survival of the fittest ensured this preference for sweet foods as they are higher in calories, providing energy and so aided survival.
I do understand how parents bargain desserts against main meals. I found myself inclined to do it too and Oscar is only 6 months old! Keep perservering with the less sweet foods. These will take more attempts before they are accepted but worth it in the long term. It may take as many as 21 attempts before your child accepts a food.
TOP TIP: Don’t give up trying vegetables. Mix them with a fruit or sweeter vegetables like sweet potato to make them more appealing but still keep trying them by themselves.
Steiner JE “Facial Expression of the Neonate Infant Indicating the Hedonics of Food-Related Chemical Stimuli” in Taste and Development, ed. JM Weiffenbach, Bethesda, MD;US Department of Health, Education, and Welfare, 1977 pp. 174-175