attractive yan tai weighed just over seven stone when she began dating you pan in south china 's guangdong province .
but two years on when you asked her to marry him she was almost unrecognizable , according to the people 's daily .
yan 's weight had almost doubled - after she ballooned up to 14 stone 2 lbs .
but her six-and-a-half-stone weight gain was all part of plan to keep you 's pretty girlfriend by his side forever .