I see this question a lot on Reddit and I always answer the same way, with science.
You can change your eating habits and exercise, staying at your TDEE to avoid weight gain. But it's super hard because it's not just a lifestyle issue, it's about metabolism.
Take a look at this study:
https://assets.ctfassets.net/kg5lkg...e23113c31591b8b20758b8/nejmoa2307532_full.pdf
It's the SURMOUNT-1 3-year extension. They gave tirz for 3 years, then stopped. In 17 weeks, most of them (like 83%?) gained back about 7% of their weight (in 17 weeks!) and their cardiovascular health went down (blood pressure, cholesterol, A1C all went up). We don't know if they kept up their lifestyles during those 17 weeks; it took 3 years to get used to it!
Most diets and lifestyle changes fail, and even gastric bypass has a failure rate after some years.
One of the SURMOUNT researchers said that GLP-1s push your "set point" or "defended fat mass" lower. When you stop taking them, your body freaks out and makes you hungry/adapts your metabolism to regain the weight. Adipose tissue has a "memory."
More about that here:
https://www.nature.com/articles/s41387-023-00291-1
And what's the set point:
https://health.clevelandclinic.org/set-point-theory
If you weren't obese for long or your weight loss was small, you might have better luck. If you have a history of disordered eating, were obese for years, lost a lot of weight, have insulin resistance, pre-diabetes, or are going through menopause, it'll be harder.
You might tough it out, or be one of the lucky few who can do the hard work without issues, but it won't be fun. You'll be hungry, and your body will fight you.
I'm staying on these meds for life. I'll find the right dose and schedule. Good luck!