whenever I could. I used the Noom app to track my meals (it's free).
Can't say that will work for everyone, but it worked for me (I'm a bit younger at 28, single so it's easy to shop just for myself, and I work from home so I can prepare what I eat everyday).
My favorite meal that I found to be super easy is the Costco chili. It's 380 calories for every 10.67 ounces (so 712 calories if you ate 20 oz, which is a lot, in one meal) and it's 2.7 grams of protein every ounce (so 54 grams of protein for a 20 oz serving). Just takes 2 minutes to heat in the microwave, it tastes delicious, and fills you for a long time due to such high protein intake.
The price for each container varies by weight, but it's typically 4 lbs of chili per container for about $15-$17. Can easily split that into 3 meals (if you do the 20 oz portions), so it's actually a cheap meal too.