Health experts have seen that the weight status of couples tends to move in sync. It is often similar when they get married, and if one partner gains weight over time, the other does as well. In fact, researchers have found that if one half a couple becomes obese, the risk that the other will follow suit rises by 37 percent.
There are signs that the reverse is true as well. A long-term population study in England suggests that when one spouse loses weight, a "ripple effect" extends to the other spouse. Another study of bariatric surgery patients found that nearly two-thirds of their spouses were lighter a year after the procedure, with a median weight loss of just under 3 pounds.
Source: Medical Xpress