BSN products are one of the very best. BSN Nitrix, BSN CellMass, also as you mentioned, TrueMass is also looking good. With it’s nutrition label, you might have to skip two meals, 16 g of fat, this is heavy stuff. Related to meal replacements, Manno’s Advantage is also quite decent. Only 2 g of fat per 33 g of protein.
What BSN products have you used, any experience with them?
Best is to leave gap in-between for an entire 24 hours. As Iori stated, a short 15-/20-minute cardio works out in your favor because you will be burning the fat a lot more quickly. The only downside per person is ensure that you are also taking in a relatively good number of grams of protein in your body right after your workout. That is when your body taps into and sucks in all the sources of energy and if there are no proteins left in your body to take advantage of and convert that into energy, your body ends up tapping into your muscles for energy source, which is what you might look to avoid.
If your goal is fat loss with no muscle gain, simply cardio can get you there. When you mentioned that doing both things together at the same time could result in no muscle gain, yes, it could actually reduce your muscle mass considerably. That is when you have to give your body all the energy it can get from proteins. Without it, your body suffers from high muscle-to-energy ratio and the strength in your muscles starts to get weaker.