You will find that an unbranded T-shirt is a reliable go-to piece.
3 Pack Men Body Shaper Slimming Shirts Vest Compression Short Sleeve Shapewear
A nice touch is the adjustable hem with a built-in elastic cord.
Mens 1/5 Pack Body Shaper Slimming Tummy Vest Thermal Compression Shirt Tank Top
What stands out about this shirt is its unisex adult cut, which is straightforward.
Men Slimming Body Shaper Posture Corrector Vest Abdomen Compression Shirt Top
You will find that unisex adult shirts like this are a wardrobe essential.