I’m not sure any diet is 100% sustainable. I mean by that you can stick to the eating plan of the diet 100%. I find as a senior, that the budget is a consideration. If Del Taco has tacos for $0.59, going out to eat and saving money may lead you there. If Steak ‘n Shake has hamburger and fries for less than $4, it’s hard to pass up if you take the grandkids out to eat lunch.
I don’t know of any diet plan that allows those things on the eating plan. And traveling presents all kinds of eating dilemmas especially with cost. It seems most diet plans are by people who don’t have to consider money when making up their recipes. Lots of them are doctors, and many even sell products they have developed.
But to the average dieter and especially the senior on a reduced income, the eating plan must fit the budget or it’s just not sustainable. Somehow a trip to Del Taco for 59 cents tacos has to fit in the plan. If the plan excludes those things, then you have diminished the chances for success.