Feed him good, wholesome, home cooked food. Add carbohydrates and dairy. I’m sure he’ll gain weight at some stage

I would try adding milk shakes and smoothies and ice cream can be a good one too (you can make beautiful nutritious ice cream yourself). I would try to avoid adding “heavy” things as his tummy probably won’t tolerate it, but serve breakfast, lunch and dinner in normal portions and morning tea afternoon snack and when possible desert.
When you’re really concerned I would suggest to get a referral to a dietician.

The maternal health nurse told me avocado – plenty of good fats, and nuts. Add cream to cooked foods. And just generally try and make his meals bigger. You could make healthy snacks like chickpea cookies, eggplant brownies etc.

Perhaps try beating an egg (if he’s not allergic) and add it to hot chocolate drinks.

Fed him normal food. Maybe increase his meals throughout the day. 6 smaller meals instead of 3 big ones

Try things with cream and nuts (if they’re not allergic). They have a lot of calories and good fats and oils.

Have you tried more meals? Not just the normal breakfast lunch and dinner. Have them plus morning and afternoon teas and a supper before bed. Keep it healthy though, you don’t want him to put on weight by feeding him crap!

good luck. great suggestions here. try to offer more foods that they like

Id see a dietician personally to get a good idea on what to give!

I would be adding some sustagen. They do have a kids specific one

Our doctors and chemist suggested sustegen hospital in vanilla or chocolate with full cream milk

Add some sustagen to your son’s milk – it is a bulking powder. Given to lots of people with illnesses. Our Doc prescribed it for Dad when he was sick with Cancer. Hey, also don’t forget the good old malted milkshake – malt is also a bulking powder, add a raw egg to the milkshake. You cannot taste it, and it makes the milk really frothy – kids love it. All the best sweetheart. Kaz

I would get advise for a nutritionist or dietatition due its hard when kids will not eat certain foods so they may be able to help you work with the ones he likes.

Try and get good fats into her. Things like egg (so maybe making French toast/omelettes) and avocado could be 2 good options.

Our daughter was the same way. We had to firstly slowly stretch her stomach by making her eat a little more each day/week. Also, we gave her a big breakfast including cereal, toast and yogurt.