CalorieMate (カロリーメイト) is a brand of energy-supplement foods produced by Otsuka Pharmaceutical Co., in Japan. It was first released in 1983 debuting with the cheese-flavored block.
CalorieMate comes in several forms, including Block, Jelly, and Can. CalorieMate Block (カロリーメイト ブロック) resembles a bar-shaped cookie (somewhat like a shortbread), sold in packs of either two or four. CalorieMate Jelly (カロリーメイト ゼリー) is gelatin sold in a pouch with a spout. CalorieMate Can (カロリーメイト 缶) is a canned drink. The packaging is quite plain, almost generic. ~Wikipedia
Being a well-known supplemental food in Japan, it has appeared in various Japanese subcultures, such as Metal Gear Solid 3 and 4.