Acid/Basic food

There are foods that make our bodies more alkaline and other foods that create a more acidic environment.  In a nut shell, the goal is a body that is more alkaline (aka basic).  A PH below 7 is considered acid, and a PH above 7 is considered basic, or alkaline.  (A PH of 7 is neutral.) A lot of stuff  we don't want (cancer for instance,) thrives in an acidic body, but isn't too happy about residing in one that is alkaline, thankfully.  The site acidalkalinediet.com has especially nice charts showing the Ph of different foods.  Not surprisingly  most vegetables are alkalizing, fresh fruits and nuts are somewhere in the middle, and meats, coffee and black tea the most acidic.  Consuming primarily basic and neutral foods is my personal goal. (FYI:  simply put, PH stands for 'power of hydrogen'.)
Another topic to consider that you may notice on that site concerns proper food combining for better digestion and subsequently better food absorption.  It is a personal decision how strictly to adhere to the food combining, but it may be worth trying for a week or so to see if your food digestion improves.
Along those lines also, it has been my experience that mixing in a teaspoon or so of fresh lemon juice in a mug of warm water seems to balance the system in general, and 2-3 teaspoons of apple cider vinegar in a warm mug of water  really eases a bad case of indigestion, including the times accompanied with bloating.  (Start with one teaspoon and work your way up to 2 or 3, it's an acquired taste!)  Also heating and eating a cup or two of plain canned tomatoes (with a little garlic powder added) between meals rights my system when I have eaten too much.  (Of course not eating too much at the next meal helps too!)  My brain still figures I can eat the same as I could in my 20s, 30s, and even 40s, and sometimes forgets less food is required in the 50s, and what is eaten digests slower. 
Every one's system is different.  In trying new ways of eating, and possibly in new combinations, you may find new tools that work for you.
When our digestive systems are happy, we are happier too!