I had a minor surgery at around your age, with a much shorter recovery time (around two months), but I had similar concerns. I ate less, partially a conscious effort but also I think I was less hungry due to being less active. I did not gain weight and overall did not lose much of my fitness.

As for the pressure to eat pizza, drink beer, and eat ice cream, just politely decline. You know you can have those things if you want them, but don't let anyone pressure you to eat or drink when you don't want to. Your desire to stay on track with your nutrition goals should be stronger than the temptation to give in to someone else's expectations.

You'll get through this!

Have you ever struggled with your weight? Do you have any reason to believe that your body won’t naturally adjust your hunger levels and intake based on your lower activity and energy expenditure?

Trying to tell a long-story short:

I'm very athletic and in my mid-30s. I need to have hip surgery before age 40 and it's going to be a very long recovery: 3 months on crutches, 6 months of PT, one year until I can try and resume all activities. In order to get back to the lifestyle I am used to, it is very important that I do not gain weight. Not only does gaining weight put more stress on my joints, but it can delay recovery and make it even harder to get active again.

Because I am so active, I have an absolutely voracious appetite. And, at least so far, a metabolism to match. Also, it should be known that this isn't a vanity thing for me, it's a lifestyle thing. I acknowledge that some body changes are inevitable and I will be facing them in the next 10-15 years or so if you know what I mean, but I don't want this surgery to be the end of my athletic lifestyle and never be the same.

I plan on following PT religiously, and taking up swimming as soon as I'm cleared to do that, and continuing to work on my upper body strength. However, what I need help with is willpower to maintain a lower-calorie diet. And advice for my family that I already know is going to make it harder. I can already here them say "oh come on, you deserve some ice cream after your hospital stay!" or "come on, occasionally having pizza and beer won't hurt you." They won't take it as seriously as I do.