Marathon Training and Reta.

I've been on Reta for about 12 weeks.. From a 101kg to 86kg... went from 1mg to 4mg. Tracking Calories and Protien...Running about 35 miles including one longish run run a week (,Around 20k) and lifing 4 days a week.

I should hit a Goal weight in a few weeks and want to start Training to run a Marthon ( I've run many in the past..so I know what it Takes) . I know that my Training will Suck if I stay living in a Huge calorie deficit ...So I need to eat more. But also Don't want to lose all the gains ( it's been years since I've been this weight). Has anyone tapered down and been able to eat a little more normal. 1200 -1500 calories ain't going to cut it.