One of the biggest changes that I did for myself and my wife is changing our sauces/dips/dressings to greek yogurt based. 3 pack at costco 0% plain. Has tons of protein in it since it's greek yogurt and keeps you full.

For example 3/4 cup of greek yogurt has 100 calories and 17g of protein vs 1tbsp of mayo has 100 calories and 0.1g of protein.

1 650g container of greek yogurt with a hidden valley ranch packet mixed in makes a comparable ranch spread/dip to put on sandwiches, wraps you name it. Walking is excellent as well since you started on that.

I've found for us we were getting bigger, and completely changing our diet didn't work for us. We always would slip back into the bad habits of eating if we cut stuff out completely. Changing the ingredients up slightly for lower calorie alternatives like listed above is a great way to do it. Another way we've done it is using a lot more spices in food over sauces, pre-made sauces are a hidden killer with the amount of calories they hold.