His weight and height are below the 3rd percentile for his age. Sometimes when children are smaller, it maybe genetic. Are there smaller stature males in the family? If he is gaining weight and growing at a steady rate, no matter how slow, that is considered he is alright but small. Suggest the following to wean him off breast milk to regular milk: mixing ¾ breast milk with ¼ regular milk and see if he accepts and tolerates it. If he does, then after a week or so, try doing a bottle mix of ½ breast milk, and ½ regular milk. Gradually go to a bottle mix of ¼ breast milk and ¾ regular milk then totally to all milk. After he is on regular milk, suggest making milkshakes (milk and ice cream blended) in place of milk for every meal, for additional calories/protein to help gain weight. A recommended guideline for a 12 month old child should eat the following: Dairy 3-4 feedings a day – Milk (6-8oz), cheese (½ oz), yogurt (½ cup). Starch 2 feedings a day – Infant Cereal (2-4 Tbsp), pasta (3-4 Tbsp), bread (½ slice), or crackers (2). Fruits & Vegetables 2-3 feedings a day – Fruits (3-4 Tbsp- including 100% juice limited to only 3ozs) & Vegetables (3-4 Tbsp). Protein source 2 feedings a day – Meat (3-4 Tbsp), or beans (¼ cup). The food should be eaten as 3 meals and have snacks between meals using the foods above to be spread out throughout the day. At this age you can give him ‘finger foods’ (regular food cut up in small pieces) to start eating on his own with his fingers. Hoped this helped you.