Rush Limbaugh’s newly sleek physique was a short time coming. The right-wing radio host has gone from portly to paunch-free in a mere five months.

Limbaugh confirmed to American Superstar Magazine that he’s using a diet from Quick Weight Loss Centers and eating about 1,500 calories per day. On his Web site, the suddenly sylph-like Limbaugh describes his diet as “based on actual food that you buy at the grocery store, a couple supplements that they provide you.”

Limbaugh has professed ignorance as to how his diet works, despite numerous queries since he announced his weight loss plans in March.

"Folks, it's not that I won't tell you, it's just I can't," he said in June. "It's too complicated. I mean putting the menu together is a jigsaw puzzle every day. It would take me 45 minutes every day to tell you what the diet plan is and answer all your questions about why it works."

Quick-fix diets often don’t work over the long haul, experts say. When dieters lose weight that quickly, the pounds tend to pile back on once they stop the starvation regimen.