Barry Manilow barely eats and only has a meal when he starts shaking with hunger. The 80-year-old entertainer has opened up about his unhealthy habits admitting he often goes so long without food he starts “trembling” and sees it as his body’s way of telling him to eat something while he also revealed he goes to bed at midnight and is up at 4am every day. He told The Hollywood Reporter: “I don’t eat and I don’t sleep. That’s also the trick [to staying in shape] … I often find myself trembling and think: ‘Oh I should get some calories in me’.” However, Manilow revealed he’s managed to quit sm…