Peanut butter - Spread - soft, salty peanut butter on bread. It gives you approximately 192 calories plus it is extra high in protein.
Energy bars - It is loaded with good-for-you nuts and oats. One bowl packs around 500 calories, which is healthy as well as yummy for breakfast.
Cheese - One serving of cheddar cheese packs a good 69 calories. Cheese is concentrated milk, so it is high in protein and calcium, fat, cholesterol and cheese calories.
Oil - Adding extra fat to your food is an easy way to add calories, choose olive oil, canola oil, etc. which is good for your health and will add those much needed calories too.
Banana - One banana contains approximately 100 calories. Not only are bananas rich in carbs and nutritious, they're also great for workout fuel.