Moving in together may take your relationship to the next level, but it can also bump up that number on the scale. Theresa, 26, was svelte when she and her boyfriend, Rosario, put their names on the same mailbox, but things soon changed.
"I ate whenever he did, even if I was stuffed," she says. Theresa ignored her expanding waistline until she saw a shocking photo. "It looked like I had three stomachs!" she exclaims. And she was equally stunned when, eight months after moving in together, she had gained 40 pounds.
Theresa’s not the only one to fall victim to "love lard" (the weight gain that often accompanies falling head over heels). Last April, researchers at Newcastle University looked at studies that examined the eating habits of over 12,000 cohabitating or married couples in Europe, North America, and Australia. In a trend called "dietary convergence," they found that after a twosome begins to cohabitate, women start consuming more junk, while men’s diets tend to improve.
But why do we pork out when we pair up? "Your guy has food that you’d never bring in your house," says dietitian Lisa Young, PhD, author of The Portion Teller Plan. "But half the battle is recognizing that this could be a problem and being proactive about it." Read on to get the skinny on the most common weight issues—and how to keep them at bay.