Lot's of people complain about MSG though reportedly less than 5% of the population is sensitive to it. IT comes in all sorts of snack foods. I have some on the spice shelf which MAY get used maybe once a year. There was a successful product called "Accent" which was heavily advertised and universally used until the MSG thing hit in the 1970's. I don't know if it exists any longer.
I don't know how to discriminate MSG is present in a meal and I have tasted the MSG as-is. Yet, I will see people claim some restaurant uses too much MSG. Often this is a Chinese restaurant, where there are present a variety of sauces and ingrediants we don't usually encounter or could identify individually. Sometimes I think this identification of MSG is really something else or simply someone pontificating! If you cannot taste it is present and someone claims it is, then how can you question their opinion?
I was at a Chinese banquet a few years ago, on the onset of the meal someone blurted out, "No MSG, I am very sensitive." You could have heard a pin drop before the owner piped up there was no MSG. For a moment, it almost seemed like the evening was ruined by this complainer who could have asked this LONG in advance.
Claims of MSG in a restaurant's food is almost akin to a report of a hair on a plate or a rat seen scampering across the room (whether these are true or not). The worst thing is that something like that immediately kills a discussion. Everyone shuts up because how could you argue against the presence of MSG (or the rat or hair).
By the way, I have no stock in Accent or make homebrew MSG in the basement.
How can you definitively tell there is MSG in your food? If you cannot tell, then should this even be a criteria for evaluating a restaurant? So what do you think?