If you start to notice side effects, such as the beginning stages of gynecomastia, excessive water retention, or high blood pressure despite using anti-estrogen medications to prevent them, then your Deca Durabolin dosage is likely too high for your body. Just as you titrated your dose upward, begin to titrate back down if you notice these bothersome side effects. As an example, if you were taking four 100mg doses per week, use four 75mg doses per week, instead. This will shave 100mg per week off of your overall dose, and you should notice a difference. If not, go down to three 75mg doses per week.
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