A meal plan is great but in terms of weight loss and specific weight loss

One: the issue may or may not be as simple as meal planning
Two: Long term total and restrictive meal planning may not be needed

Working in terms of weight loss I use a rule called the two ingredient or two macro rule. All that means is that for 99% of people their weight issues (nutritional) are caused by either one or two ingredients/macro and not their complete eating habits in general. People with normal resting metabolic rates are going to be hyper responders or hyper sensitive to one to two ingredients or macro nutrients that they consume everyday. Some people may be hyper responders to carbs some may be hyper responsive to carbs when only consumed as refined carbs or added sugars. Others may be sensitive to fat, others protein excess. As a result eating healthy or eating for weight loss can and almost always looks very different from person to person.

Also, understanding what specific ingredients or macros you need to cut or manage will help you stay on track with your new meal plan as you won`t need to completely restrict yourself from all foods that you enjoy. This is where most people fail. There`s a point a few days, weeks or months down the road where temptation gets the best of them and that "cheat meal" turns into a cheat day, which turns into a cheat week then a cheat month and you are back to square one.

In terms of general health daily McDonalds runs are not a good idea but its very possible that its not the general McDonalds meal that`s hitting your guy but the way you are responding to specific things in that meal. Also understand that as you age the impact will become greater so if the impact seems greater recently, first take a visit to your general healthcare provider and make sure there are no underlying health issues causing the weight gain and if not understand your body may be telling you moving forward you are not going to be able to get away with your previous/current lifestyle.