My first instinct was to simply write "food". Then I decided to not be a douchebag.
What you should remember is a lot of those Weight Gainers are sugar sugar sugar. Try the patented Harris447KCalBomb nce or twice before investing in one of those buckets of pixie sticks.
1.5 cups milk (I prefer 2%)
2 scoops protein powder
2 packets instant oatmeal
1-2 tbsps NATURAL peanut butter (None of that Skippy or Jif nonsense)
1 tbsp flax/fish oil
Blend well, chug.
900 calories, a good ratio of P/C/F, and no sugar or trans-fats or any other shit.
If you want some simple carbs as well, add some honey.
Does it taste like Nathan's hot dog and an Orange Crush in a glass bottle? Hell, no. But it's good for ya.