Look into what a "Ghrelin Rebound" is. Basically, during exercise your body suppresses hunger hormones like ghrelin, but once you stop and your body temp normalises, the ghrelin levels can rebound to higher than your typical baseline, causing you to feel "starving", even though you just ate. You're going to be burning through your carbohydrates (glycogen), so if your post-workout meals don't adequately replenish those stores, your brain will repeatedly signal that you need food. It'll keep pestering you, essentially.

You're also right to be thinking about hydration. As you're probably aware, dehydration often mimics hunger because the brain's thirst and appetite centres share the same signalling pathways. You could very well be dehydrated, which makes you think you need to fill yourself with extra food. In fact, many people are dehydrated daily and are blissfully unaware.

So yeah, you may need to up the carbs as part of the post-run or workout meal. Something like 3:1 (carbs to protein) to stabilise blood sugar and refill glycogen (like I mentioned earlier). And chug some water after exercise and before your next meal so your brain can let you know if you were actually hungry, or if it was just thirst.

Anyway, I'm rambling on. There are a few things you can try. You're possibly not eating as many calories as you're burning, your glycogen is rebounding after exercise and pestering your brain, and you perhaps need to hydrate a little more.

Also, don't fret! If your metabolism is very high, you can get away with eating more food than the average person and remaining at a consistent weight! My elderly mother, for example, is very active, walks 10 miles per day, and has a large appetite. She's tiny! It differs from person to person.

You need to get the calculator out and monitor how many calories you're burning compared to how many you're consuming. What you've described is a clear sign that your Total Daily Energy Expenditure (someone else mentioned it here as TDEE) is likely higher than your current intake.

As you only know your size (weight and height), I'll give approximates. If you're of average size and weight, you would likely need somewhere between 2,100 and 2,500 calories per day for your maintenance calories. Given you likely burn 1,500–1,800 extra calories per week from running, and 300–500 calories per day (10k steps), combined with weight training boosting metabolism for up to 36 hours after, you could be at a significant deficit. I am guessing that you're not trying to lose weight?

I'd also look into what a "Ghrelin Rebound" is. Basically, during exercise your body suppresses hunger hormones like ghrelin, but once you stop and your body temp normalises, the ghrelin levels can rebound to higher than your typical baseline, causing you to feel "starving", even though you just ate. You're going to be burning through your carbohydrates (glycogen), so if your post-workout meals don't sufficiently restock those stores, your brain will consistently send signals to your body that you need food. It'll keep pestering you, essentially.

You're also right to be thinking about hydration. As you're probably aware, dehydration often mimics hunger because the brain's thirst and appetite centres share the same signalling pathways. You could very well be dehydrated, which makes you think you need to fill yourself with extra food. In fact, many people are dehydrated daily and are blissfully unaware.

So yeah, if you're not aiming to cut calories and lose weight (again, I don't think you mentioned that), try to get closer to your maintenance level of calories. Also, you may need to up the carbs as part of the post-run or workout meal. Something like 3:1 (carbs to protein) to stabilise blood sugar and refill glycogen (like I mentioned earlier). And chug some water after exercise and before your next meal so your brain can let you know if you were actually hungry, or if it was just thirst.

Anyway, I'm rambling on. There are a few things you can try. Likely, you're not eating as many calories as you're burning, your glycogen is rebounding after exercise and pestering your brain, and you perhaps need to hydrate a little more.