Food is the foundation - the bricks and mortar of your castle. AAS just keeps the workers moving and building bigger walls
With that analogy said, food can easily trigger different hormonal patterns... anabolic hormones... like anabolic steroids, insulin and growth hormone...
Here is one example is testosterone: How you eat can cause your body to produce more testosterone; or it could trigger you body to lower endogenous testosterone levels. Your body cares about survival - not cosmetic gratification. Holding a lot of muscle is metabolicaly expensive and can be dangerous to survival in the event of famine. Restricting calories or eating below your basal metabolic rate for too long can cause a drop in testosterone... this helps to shed off some of that un-economical muscle mass (once again - your body doesn't care about being big
and cut). Onh the flip side, overeating (healthy fats seem to be very supportive) can keep this starvation response from becoming to overwhelming and boost testosterone secretion - with progressive resitance, training the body accepts more musculature. This is why most productive cutting diets swing calories with periods of low dieting and high calorie re-feeds...