Baby needs to gain weight but won't eat

[jahncrish]

Hi! So, my baby brother is 8 months old and weights less than what is expected, besides that, everything is fine with him according to the pediatrician. Almost everyone in my house has tried to feed him with no avail, he won't eat more than small portions and even then he makes a fuss about it. For breakfast, he usually has a bit of passion fruit juice, half of a mashed banana, and some scrambled eggs, then some milk after; for lunch he eats a small plate of liquified soup, then his milk at like 3 or 4; at 6 he has more soup, and finally at 8 some milk.
This has been causing a lot of tension in the house, since my mom tends to "lose it" quite often and screams at everyone out of frustration. I just want my brother to be OK, so could you please share some of your tips to get him to eat more? Just now he's crying because he only had 2 ounces of soup for lunch and he still doesn't want to drink his formula.
UPDATE: Thanks so much to everyone who gave kind advice! Baby is thriving and has grown and gained quite a lot of weight in the past few weeks

 

[greggkj]

@jahncrish Are you guys only offering soup? At 8 months I think he could handle other soft foods like various fruits (blueberries and raspberries mashed). He should still get most of his nutrition from formula.

When you say milk- do you mean cows milk, breast milk, or formula?

 

[jahncrish]

@greggkj Formula! He was never breast fed. About the soup-- no, we give him fish, some chicken, lentils, and more. He just genuenly doesn't want to eat unless we show him youtube videos or TV, and that's IF he's in a good mood.

 

[greggkj]

@jahncrish Offer the formula BEFORE the food. He’s filling up on things that don’t have much nutrition. He will drink more formula if it’s an empty stomach.

At one year old you switch and offer milk after food.