Yes counting calories is essential, I had very similar experience (walk 10 km on the weekend ~= burn 600 kcal, then buy a 1000 kcal snack on the way back and wonder why I'm not losing weight), but still the exercise makes a big difference.
Last year in march I started counting calories, recording my weight and all exercises I did and walking/biking every day.
I lost 30 kg, walked 2100 km, biked 1000 km, and the sum of calories burned by all exercise was about 160 000 which is about 20 kg of fat loss, so naively the remaining 10 kg was diet. Of course you cannot divide it like that - if I wasn't counting calories I would eat the 20 kg back easily. But if I wasn't walking I wouldn't be able to restrict the calories as much. I've been eating on average 2000 kcal and had average deficit of about 500 kcal. Without exercise I would have to eat 1500 on average which for me feels much worse than 2000. Also walking helps for a lot of unrelated things.
Last year in march I started counting calories, recording my weight and all exercises I did and walking/biking every day.
I lost 30 kg, walked 2100 km, biked 1000 km, and the sum of calories burned by all exercise was about 160 000 which is about 20 kg of fat loss, so naively the remaining 10 kg was diet. Of course you cannot divide it like that - if I wasn't counting calories I would eat the 20 kg back easily. But if I wasn't walking I wouldn't be able to restrict the calories as much. I've been eating on average 2000 kcal and had average deficit of about 500 kcal. Without exercise I would have to eat 1500 on average which for me feels much worse than 2000. Also walking helps for a lot of unrelated things.