Food can last ~2 weeks in the fridge. For me, if my food variety feels repetitive, it is because my cooking needs some work. I can eat the same thing every day easily, if the food is really good.

Here's the thing, "healthy" and how you feel is complicated and likely has to do with IBS to some degree. You likely have many very poor quality options available, but are not looking at the ingredients in detail. Like the oil used is a major factor in how you feel just under the surface of most people's awareness. Unhydrogenated oils may make an enormous difference, as will either sticking to grass fed dairy or eliminating dairy all together.

I was 350lbs and lost all of it down to below 190lbs while riding and eventually racing bicycles. At around 3500-4000 calories per day, a lot of subtle problems become much larger and require attention. Processed industrially produced foods are universally terrible. Almost everything in the center isles of an American grocery store are garbage to avoid. Only eat things that look like how they grew.

All you need to do is shop for nice containers to use for all stages of cooking and transport. This is the "convenience" conditioning we were all trained to forget as dumb little American consumers.

The healthiest person I ever worked with in a bike shop back office was an Olympic athlete. He never ate "meals." He came to work looking like a tupperware salesman. He ate small amounts of a bunch of different side dish like foods he made in their own small containers. His diet shifted to exactly what he was doing physically each day and he was amazing on a bike.

"Meals" are the primary problem. How much you eat at one time determines a whole lot. Your body does not keep cycling that glucose through your bloodstream. It does a few laps and turns to fat. Then you have low blood sugar until your next pie hole infusion. All your muscles can deal with that except for your brain. That one requires glucose only, and so you feel bad when it is resource poor.

The solution is to eat more often, but far less, and things that take time to break down as they will provide more glucose over longer periods of time. Processed means predigested; means the nutrition info is garbage. It will go through you quickly and that will inevitably lead to low glucose for the grey goo. I cook several large casserole dishes full of meat and veggies every 8-12 days.

How much you eat at once and how often is the most important factor. Second is the micro nutrient density. Third is isolating IBS factors.