To help you understand though, milk when it's made would have added ingredients so judging milk to an apple is you looking at it completely the other way.Everything you just linked contains the same macros as just a cup of milk lmao. 40 cal protein 72cal cal fat 48cal carbs. Pretty rounded if you ask me. Obviously you should eat other things because of other nutrients but you seem to be comparing apples to apples without realizing it.
He should have a stable diet, he only mentioned he intakes a shake which gives him around 1k calories and there are many of them. He should be taking roughly 3.2K - 3.5K calories/day as a skinny/small guy to put on weight and this would be from things such as nuts, berries, meats, veggies, rices, pasta and so on. Not just fucking milk lol...














