Do not criticize anything at mealtime. Studies have shown that children eat less and do not do as well nutritionally when they are catching a lot of criticism from their parents. Consequences, not criticism, work for improving mealtime behavior. Set reasonable expectations about behavior at the table and what will happen if they don't comply. Hand out the consequences promptly and they'll know you mean business.
Mealtime behavior is a matter of degree and attitude.
Simple kid behaviors include using fingers to push peas onto a spoon or picking up pieces of meat. Don't despair, acceptance of a greater variety of foods will increase. Bad behaviors include an attitudinal shift and include whining or complaining about the food, begging for foods that are not on the table, or eating in disgusting ways. Make Mealtime Pleasant Make mealtime pleasant with conversation and sharing. You don't need to be concerned with how much or how little he eats.