My husband and I both gained weight after we were married because we LOVE good food, cooking together, and hosting. I gained much more weight than he did with bearing children, emotional eating, and a few other factors.
My weight did affect our marriage, though not in the way you would think. My husband never once told me I was unattractive or let my weight turn him off. He loved me as a spouse should with all my flaws. How it affected our relationship is I didn't love me. I was insecure about my choices, my body, and my excess baggage. I became much more needy, defensive, and unhappy. He felt helpless.
Fortunately, we've come a long way since first being married and will celebrate our 10th anniversary this August. Over the last few years I've pursued a much healthier lifestyle in every regard including how much I exercise, how I navigate adversity, how I solve problems, how I behave in relationships, how I get what I want, and how I manage my family's healthier diet. I've still got a way to go, but I'm stronger, more fit, more confident, and more satisfied with myself, and our marriage has also enjoyed the benefits.
Thanks for all you do!