A very important factor in a good oral intake is fixed meal times,with NO snacking inbetween. Also,if the intake part meal is very less,you may give them more frequently. In general,give just 2 milk feeds using a glass and 3-4 solid meals a day including curd and Banana in the diet. Make food tasty and interesting,and mealtimes fun,rather than an ordeal for both you and him!! Having said that,the main two criteria of children's health are,the level of physical activity and mental alertness,and secondly,weight and height,both as per age,and also,a regular gain in both over a period of time. Your child is in in normal range,but on the lower side. Try the above mentioned instructions.