I wouldn't do the shortcut to size nutrition regiment if one is truly looking to cut fat and that's the preeminent goal at the time.
Stoppani's "shortcut to size" diet regiment calls for 18 calories/lb of body weight on non-workout days and 20 calories/lb of body weight on training days. That's not going work well for someone that truly wants to shed fat mass.
Here's what I'd recommend:
Start logging all food - even bites, licks and tastes. Track your daily caloric intake meticulously and don't deceive yourself.
If you're okay with a gradual loss of fat mass (1-2 lbs/week) and not seeking anything rapid, shoot for something like eating at maintenance calories 3-4 days week, preferably training days, then shooting for a 500 calorie deficit on the other 3-4 off days. Basically you can eat whatever you want, but I'd strive to get 80+% of my calories from whole, minimally processed foods. The other 20% or so can come from whatever you like, as long as you stick within your caloric guidelines.
On training days, you could do 1g/lb of body weight in protein, 1 g/lb of body weight in carbs, and allow the remaining 0.5g/lb body weight to come from fat, or whatever other combination you prefer between carbs and fats. On off days, I'd keep protein intake set at 1g/lb body weight, then keep carbs at or below 100g, and the remaining calories from fat, which allows for an approximately 500 calorie deficit.
There are many cutting approaches, from low carb to low fat, but everyone pretty much agrees that you have to be in a consistent caloric deficit to lose fat, so ultimately controlling calorie intake is what matters. You want to consume enough carbs so that performance doesn't suffer, so how you choose to manipulate carb vs. fat macros is your choice. You can certainly choose a lower carb or a lower fat approach, but protein intake should be kept consistent at probably 1g/lb of body weight, and you want to strive to stay within your set calorie intake on a regular basis.
- Pick some form of conditioning that you enjoy, and have at it at least 2-3x/week for 30-60 minutes.