Depends on the amount of time. I'm initially really uncertain because of that concern, but I think as the more I think about it and put words into concrete form, the more I want to do this. Not just for weight, but for other reasons, too. But weight and health are primary reasons for doing this, I should say.
At first, KISS. If it turns into a sustainable habit then by all means budget more time. Gotta restrict timing on the front end if potential commitment is an issue. So how do you accomplish that?
Prioritize grab-and-go foods - for fruits and veggies (bananas, apples, grape tomatoes, snap peas, etc) instead of ones that require work at home before they're actually ready (pineapple, watermelon, peppers, cucumber, etc). Doesn't get much easier than individual portions of low sugar greek yogurt. Get a few cans of tuna on standby - pairs well with grape tomatoes (and red onion - but that requires work). I've never tried it, but canned salmon is a thing - just add salt and pepper, maybe some lemon juice. I'm eating cottage cheese with blueberries as I'm typing this - prep time was literally just dumping 3 spoonfulls of cottage cheese in a container last night and putting a handful of berries on top. Get some sliced meats and cheeses then roll them up and shove 'em in a bag in the fridge. Gotta be careful with calorie counting, but almond butter and peanut butter go well with apples and celery (among other things) respectfully. Or just have a bag of mixed nuts/trail mix.
Once per week prepare two low maintenance proteins simultaneously - one in the oven (baked chicken) and one on the stove top (turkey chili), maybe hard boil some eggs while you're at it. Devote the amount of time it takes the chicken to bake (45-60 mins) to do anything else that doesn't fit the grab-and-go mentioned earlier. This way your only time commitment is to shop, organize once home, then however long it takes the oven dish to cook.
You don't want to prepare a full chicken meal because that will become cumbersome, but if you make enough chicken for three meals (two dinners and a lunch?) then you already have the protein ready and just need to figure out something simple to pair it with. Maybe one day you chop up a dozen or so mushrooms and throw 'em into a pan with some salt garlic and pepper for 5 mins and voila. Maybe another day you just heat up some beans or lentils. Maybe another day you just pair with some raw carrots. Or just toss a dollop of guac/hummus on the plate. Etc.
Then maybe you put two portions of the turkey chili in the fridge and three portions in the freezer. This way the turkey chili gets stretched out months - you just take a portion out in a future week when you feel like having it again or you don't have enough food in the fridge to get through the week. I think this element (preparing healthy dishes that can be frozen) and grab-and-go's are the two most important factors in developing healthier sustainable habits.
And got a week when you don't even want to devote that much time? Buy a slab of ribs for the oven (just don't tell bbq guys you're doing that). Turn the oven to 175, season it with whatever, wrap it in foil, throw it in the oven, then go do something else for 4-5 hours. Literally the only thing you have to do is cut it up sometime after its rested. Ribs are certainly not the healthiest food in the world, but compared to many well established habits (take out, pasta, pizza, etc) it's slimming just talking about it.
I could go on, but that's probably even too much.