What about the "inflation factor"?
Why do most women appear so into health and fitness BEFORE you get married, then later they just don't care anymore how many calories go into their face.
It isn't just about looks, it is also about having a partner who is healthy enough to keep up with you, able and INTERESTED in physical exercise and recreation that requires good fitness, and willing to keep to a promise to look good.
My XW let herself go after the first of 3 kids, gradually, until she was 80 pounds overweight. Biking and hiking activities were history...after that, cooking, eating, crafts, reading, and shopping were all she liked to do.
My new spouse told me when we first met that "she could never let herself go", that she would always set a goal for herself with weight and achieve it. Son after our first kid is born, her exercise dedication is really poor, she eats year round even more than I do as a 30+ mpw runner, but never exercises in the winter, and only exercises in spurts of 1 - 2 weeks before quitting a couple other times a year. She is now 60 pounds overweight and has been for 6 years. She yo-yo's, only loses 10 to 15 pounds then gains it all back again every year.
So when she is 85 years old, she will be too heavy for me to lift her into and out of a chair, probably have diabetes, too out-of-shape to even go walking with me, and meanwhile I have 40+ more years to expect a continual decline of her abililty AND willingness to do active recreational activities together with me.