Mine is kept using a black and white composition book (inexpensive).
Why? My neuro placed me on Depakote in 2016 and I gained 42 freaking pounds! A family friend on the same med last year as well gained 38 pounds! I begged to be taken off the med, so am on another one at present.
In the journal, my emphasis is in listing time eaten, listing the food or liquid eaten and its weight or volume, its caloric value in terms of carbs-fat-protein, how many 8oz portions of water I drink and at what time. My total should be somewhere around 1200-1300 Kcals per day.
I'm on a long journey, which i must complete, because I'm probably looking at an L4-5 fusion and must get this weight off.
[The thing about Depakote is that it seems to turn on the hunger center in ones brain. BAD - VERY BAD.]