I would not worry about even bothering until he is 6 months old or so.
He is at a healthy weight already. I have posted the info from the web below and hope that helps.
I have 14 month old twins and we did not start them on solids until they were able to swallow easily which was around 6 months for them. We never purchased storebought foods though, we just made our own. There are tons of places out there with recipes and ideas for making your own baby food.
Starting your baby on solid foods is the beginning of lifelong eating habits that contribute to his or her overall health. For this reason we have some general guidelines that can help you start your baby out on the right track to a healthy life.
Breast milk or infant formula supplies all of your baby's nutritional needs for at least the first 4 to 6 months of life, so don't be in a rush to start solid baby foods. Starting solids too early can cause your baby to develop food allergies. Your baby's intestinal tract is not as fully developed during the first few months and introducing solids at this time can be too much to handle
Another reason for not giving solid foods earlier than 4 to 6 months is unintentional overfeeding, since younger babies can not offer you signals when they are full, such as turning away or showing disinterest.
A third reason for holding off on solids is your baby's inability to swallow solids correctly before 4 to 6 months of age and this can potentially cause choking. And contrary to the popular myth, starting solids early will not help your child to sleep through the night.
When offering a new type of food, always feed it for several days in a row before starting another new food. This makes it easier to detect food allergies, which can present with diarrhea, vomiting, coughing, hives or a rash. Do not offer mixed ingredient foods until you are sure that the baby isn't allergic to any of the individual ingredients. Also, don't add any seasonings to your baby's foods.
Other practices to avoid are putting your baby down for a nap or sleep with a bottle of formula or juice, as this allows sugar to pool in your baby's mouth and can lead to cavities. Don't feed your baby cow's milk, honey or egg whites until your baby is at least one year of age. Also, do not give carbonated or caffeinated drinks, candy or other foods that your baby may choke on.
Remember, these are general guidelines and the amount and types of food that your baby eats may vary from day to day.