Read the following paragraph and answer the question. Give ONLY the answer, no other words or explanation.

For example:

Answer: <most likely answer, as short as possible>.

Paragraph: Nothing is more disappointing than hearing a gastric bypass patient brag that they did nt have to exercise to lose weight . Its true ; patients will lose weight without lifting a finger . In fact , for many , the lack of physical effort required to lose weight is an appealing part of weight loss surgery .

Question: Why did the person mentioned end up losing weight ?
They had surgery .
They underwent gastric bypass surgery.