Although I am usually not inclined to posit speculations on why a particular drug does or doesn't do something, in this case I will. Im guessing that the higher doses of Anadrol cause enough appetite suppression (at least anecdotally) to make eating rather difficult. It can also increase insulin resistance and glucose intolerance (5). This has the effect of making macronutrient absorption more inefficient, and could also be a factor in reducing gains when the dosage goes over 100mgs/day. Unfortunately, Anadrol also has a reasonably profound effect on your body's natural hormonal system, on par with most other oral steroids , but not as bad as most injectables, and its certainly not as harsh on your lipid profile as many anabolics are
Many advanced users stack several compounds in order to get maximum results from their cycle. Normally when your stacking these types of supplements its best to use single compounds instead of premixed stacks. The problem with using a premixed stack is you may get more of one compound than you want. Most of these products have sweet spots. Lets use h-drol for an example according to many of the forums out there 75mg is the sweet spot for this compound. Now lets say you have a halodrol product that is mixed with 10mg of Methylstenbolone. In order to get the proper amound of hdrol you will get more than the recommended dose of M-sten.