A home cooked meal is not "better" for you in terms of calories then anything else. Carbohydrates are incredibly energy dense, in ways people just don't expect.
Milk is incredibly energy dense - so is bread.
Now this is normally the point someone says "well obviously you have to cook things which don't..." - yeah. Exactly. Whether or not it's "home cooked" doesn't matter. What matters is you have a calorie budget per day and you need to not exceed it on average.
Virtuous activities don't accomplish much of anything directly. Walking just plain doesn't burn that many extra calories.[1] The benefit of that whole list is basically "it's hard to eat while you're walking or not at home or at the shops". The benefit of the improved cardio-fitness is going to make you feel better, but you won't burn a lot of extra calories.
That's what I mean about lies and judgement: "throw away the TV" - why? It's got nothing to do with anything. Sitting around reading a book is just as sedentary. Telling people they have to do a bunch of things which aren't associated with the core outcome is just setting them up to fail - or have unrealistic expectations because everyone has a different built-in sense of "correct" about food.
To actually help people you start from the core facts, and give them the tools to figure out what habits are going to work for them. Try counting calories for a week and get a sense for what healthy portion sizes and meal composition actually looks like (this is where nutrition labels help a lot). The conclusion of "do home cooked meals" is one which follows - maybe - from that exercise, but it's absolute fiction to think that it's impossible to gain weight if you only cook at home.
[1] https://greatist.com/fitness/calories-burned-walking#calorie...