There is only one truth about the human metabolism- it is incredibly adaptive.  We have evolved eating whatever we could get our hands on, our bodies can function on a majority carnivorous diet, a majority vegetarian diet and an omnivorous diet.  You can lose weight, gain muscle, rebuild your health or feel better eating any diet.

That being said your diet should still be built around whole foods, like those listed above.  

A diet is largely a game of smart sacrifice.  You need to forego some of the things you enjoy, but not all of them.  If you love cereal in the morning and can’t see yourself making it a month without it, you can include it but you need to first recognize that you will need to sacrifice something else, like pasta for dinner, to make up for the amount of carbohydrates in the cereal.  You can make a diet plan that includes your favorite foods, but still puts you in a caloric deficit.