#1 - how do you know if it is loose skin or loose fat (simply more fat you have to lose?) see http://www.nowloss.com/how-to-get-rid-of-loose-skin.htm
#2 - low carb is a good strategy but all you are really doing is flushing out excess weight and eating less calories due to limited food options + a higher protein intake BUT... if you can sustain this for a long perod of time (which most people can't) then go for it.
#3 for weight maintaince (mass or weight loss) simply watch your calorie intake and avoid the fad diets.
#4 - as for gaining mass I suggest you look at tips 11-thru-19 here @ http://www.nowloss.com/fast-muscle-building-tips.htm but specifically you need to make 25-to-50% of your diet protein and you need carbs to "FILL OUT" your muscles and wthout carbs your muscles will look flat and not oned
How do you know if it is loose skin or loose fat (simply more fat you have to lose?) see http://www.nowloss.com/how-to-get-rid-of-loose-skin.htm
Low carb is a good strategy but all you are really doing is flushing out excess weight and eating less calories due to limited food options + a higher protein intake BUT... if you can sustain this for a long perod of time (which most people can't) then go for it.
For weight maintaince (mass or weight loss) simply watch your calorie intake and avoid the fad diets.
As for gaining mass I suggest you look at tips 11-thru-19 here @ http://www.nowloss.com/fast-muscle-building-tips.htm but specifically you need to make 25-to-50% of your diet protein and you need carbs to "FILL OUT" your muscles and wthout carbs your muscles will look flat and not oned