A buffer food isn't a "cheat food" but rather a food you love that doesn't derail your goals in the gym. This is a food that satiates and satisfies in the moment. More importantly, it's a food that takes the edge off and allows for more beneficial, healthy foods to be eaten later – one that helps you reach your goals.
Don't Make Every "Bad" Food Off Limits
For most, this is counterintuitive, yet is a critical understanding. Many people think to themselves, "I will only eat foods that are healthy, fat-loss or fitness oriented foods and avoid anything else." Of course this works for a time (usually a very brief time), until you find yourself bingeing on all the off-limit foods.
Setting foods as "off limits" is like the psychological experiment where you tell someone NOT to think of a white elephant. Once you say that, it'll be all they can think about. The same thing holds true for food. Set something as off limits and it will soon become "on limits" in unlimited quantities. Instead, think about which foods you like that keep you balanced and stable.
The Banana Fix
An example, for me, is banana. When I eat it, it gives me just enough sweet, fills me up and provides good quality, stable energy. So much so it makes eating better foods later much easier. I used to avoid bananas because they had "too many carbs." As a result of avoiding them I ate even more carbs than I would otherwise... fat and salt too.
For some, two squares of dark chocolate will do the trick. For others, it's avocado, a little nut butter or sour cream, sparkling flavored water, or even a piece of bacon. Just make sure your buffer food isn't a trigger food that you just can't stop eating.