There was a survey that showed that many women like dad bods
https://www.sfgate.com/living/article/Dad-bod-still-making-women-swoon-study-finds-11222826.php
Here's another article
https://www.fatherly.com/health-science/wellness/romantic-advantages-for-fat-guys/
while I cannot cite surveys, studies or stats regarding dad bodies I would think that men having dad bods would support their own needs in maintaining the marital relationship. if a man is in excellent shape he would attract more attention from other females who are not his mates. men later in life usually garner higher income and have accumulated greater wealth. typically women are attracted to older and established men. would it not make sense that women would want a lower value male(dad bod) so that this man would not leave her? when a man has options he may be more apt to split.
as well; as stated before, I believe women would want a less attractive and fit man because of their own self esteem.

