The West Highland Way is good in this sense because (depending on how you break up the route and where you stop etc) there is very rarely a day where you don’t pass by some small village shops for resupply or a pub/hotel where you can stop and have a meal.
I completed it over 7 days and as I was planning on wild camping every night I made sure I carried 7 (plus a spare) freeze dried meals with me, so that I knew that no matter what I would always have a hot meal to make at camp in the evening. I usually buy them from Base Camp foods, they have a huge seection of brands and options.
After that I just carried a couple of days worth of energy bars, trail mix and other daytime snacks etc and relied on the shops I was passing by to restock these.
You will pass by the Oak Tree in in Balmaha probably on day 2, and that’s we’ll worth a stop for breakfast or lunch and they have a little shop selling supplies as well as their own home roasted coffee and home made ice cream (and a little memorial to iconic Scottish walker, explorer and broadcaster Tom Wier) 😃 Or a little further along the side of Loch Lomond there is the Rowardennan Hotel.
Nearer the middle of the trip when you’re up around Rannock Moor you’ll have the choice of the Bridge of Orchy hotel or the Inveroran Hotel (my preference is to walk the little extra distance to Inveroran, food is lovely and it’s a great little place) for another nice lunch or evening meal.
As you get on a couple more days you’ll pass through Tyndrum and can stop at the Green Welly for supplies and lunch, and later on again you’ll also have the Kingshouse Hotel (the original part of the building dates back over 250 years) that is very friendly to walkers and explorers, and again it’s a great chance to stop and get a lovely meal and perhaps a couple of drinks.
There are various other little villages and stops along the way, I think the way we broke up the trip there was only a single day where we didn’t pass anywhere.