Forget zombies and vampires, the scariest thing onscreen anywhere right now is Fed Up. Even Godzilla can’t rival Big Sugar as a weapon of mass destruction. In this no-frills, no-bull documentary, executive producer Laurie David, a prime force behind the Al Gore doc An Inconvenient Truth, teams up with director Stephanie Soechtig and narrator Katie Couric to tell it like it is about obesity in America. It’s not a pretty picture. Since 1980, we’ve doubled our sugar intake, seen an epidemic of Type II diabetes and watched overweight kids ascend from the exception to the norm – all thanks to processed foods. Fed Up is not a sermon, it’s a wakeup call. As the film makes alarmingly clear from interviews with dieticians, doctors, and even former President Bill Clinton, exercise is far from the cure-all. Few workout regimens, including Michelle Obama’s “Let’s Move” program, get at the root of the problem – that exercise without diet won’t get you very far. Another myth busted is the panacea of low-fat foods. Here’s just one dirty little secret: as fat is removed from food products the manufacturers replace it with sugar to improve the taste and keep us all addicted. Junk food = junkie America. Why does this happen? Let’s start with collusion. David and her team have a two-headed Goliath to battle in the form of the feds and the food industry. With fat profits come political influence, which means processed foods and expanding waistlines will be here to stay unless we all get mad as hell and refuse to take it anymore. Fed Up, unbothered by its often crude mode of attack, is definitely mad as hell. And its muckraking spirit, an anomaly in the age of giving in, is inspiring. The filmmakers wisely and powerfully focus on the children who fall victim to the system’s emaciated values. Fed Up has a fire in its belly to change things. Naïve? Maybe. So what. I say, Godspeed. Here is something rare at the multiplex: a movie that matters.