About a year ago, I was working an outdoor sales job for about 10-12 hours a day, 6 days a week and I was struggling to get in enough calories. These are the foods I ate super often to help me get in enough calories and protein. 1. Steak / Hamburg - tons of protein and fats for a large amount of calories - usually just had it for dinner. 2. Any type of protein shake (try to get no sugar added if possible if you know you won't be eating for a while) - easy to get down in the morning if you aren't a breakfast person like myself - make it with milk if you can! 3. Adding olive oil to your food - A little goes a long way - Especially good if you are going to hit your protein goal and just need the calories. 4. Dense carbs - Bread and pasta can get you more calories than rice - save these for your last meal if you have a hard time eating because they will fill you up more than other sources of carbs. These are just examples of what I did in a pinch, if there is anything you would like to add to this comment below!