Weight-loss surgery can help - and harm - the heart

Understand the risks and limitations before embarking on this last-ditch option.

An operation that changes how the stomach and intestines digest food has been hailed as a potential lifesaver for people who are severely overweight. It can dramatically improve blood sugar, lower blood pressure and cholesterol, lessen sleep apnea (a dangerous pattern of breath holding during sleep), and improve heart function. But these benefits, which accrue only with a lifelong commitment to healthy eating and exercise, must be balanced against possible risks.