You need to read Alan Aragon's article on "The Dirt on Clean Eating"
This answers all your questions
Research Review: The Dirt On Clean Eating Written By Nutrition Expert Alan Aragon | SimplyShredded.com
read this article in full. You will then have everything answered
Applying Moderation: The 10-20% Guideline
For those hoping that I’ll tell you to have fun eating whatever you want, you’re in luck. But, like everything in life, you’ll have to moderate your indulgence, and the 10-20% guideline is the best way I’ve found to do this. There currently is no compelling evidence suggesting that a diet whose calories are 80-90% from whole & minimally processed foods is not prudent enough for maximizing health, longevity, body composition, or training performance. As a matter of fact, research I just discussed points to the possibility that it’s more psychologically sound to allow a certain amount of flexibility for indulgences rather than none at all. And just to reiterate, processed does not always mean devoid of nutritional value.
The 10-20% guideline isn’t only something I’ve used successfully with clients; it’s also within the bounds of research. Aside from field observations, there are three lines of evidence that happen to concur with this guideline. I’ll start with the most liberal one and work my way down. The current Dietary Reference Intakes report by Food & Nutrition Board of the Institute of Medicine lists the upper limit of added sugars as 25% of total calories . Similarly, an exhaustive literature review by Gibson and colleagues found that 20% of total calories from added sugars is roughly the maximum amount that won’t adversely dilute the diet’s concentration of essential micronutrition . Keep in mind that both of these figures are in reference to refined, extrinsic sugars, not naturally occurring sugars within whole foods like fruit or milk. Finally, the USDA has attempted to teach moderation with their concept of the discretionary calorie allotment, defined as follows
It’s important to keep in mind that protein and fat intake should not be compromised for the sake of fitting discretionary foods into the diet. In other words, make sure discretionary intake doesn’t consistently displace essential micro- & macronutrient needs, and this includes minimum daily protein and fat targets, which vary individually. This may be tough to accept, but alcohol is not an essential nutrient.
A legitimate question is, what’s the best way to distribute discretionary calories? Should they be confined to a daily limit, or can it be a weekly limit? The best answer is to let personal preference decide. If we use a 2000 kcal diet as an example, a flat/linear approach would mean that 200-400 kcal per day can come from whatever you want, while meeting essential needs otherwise in the diet. Weekly, this translates to 1400-2800 kcal, depending on the factors I previously discussed. One nonlinear option would be to break the weekly allotment in half, where 2 days per week you indulge in 700-1400 kcal of whatever you want, keeping the remaining 5 days relatively Spartan. Again, there is no universally superior method of distributing the discretionary allotment. The same principle applies to the choice of foods to fulfill it.
What builds muscle? A caloric surplus. You will have to play with your caloric intake to find what gives you a proper surplus to gain at a comfortable rate per week.
Micronutrients will always reign supreme, as does meeting proper protein , fat and fiber intake before fitting in other foods you may classify as "Dirty"
There is no real definition of clean foods, that is merely a perception of how people look at food and their relationship towards foods. Most people don't have a proper balance or moderation outlook to consume all foods and not shelter themselves to X or Y Food sources because they lack self control when they indulge on things that are in a higher caloric allotment.
