I noticed that I have a dramatic reaction to diet coke. If I drink it, I get depressed and mood swings within 24 hours. So what we thought was emotion due to having bubs, was really the diet coke I was drinking as a pick-me-up due to lack of sleep. The challenge was eye opening.  I did a benzoate challenge and was fine. I did another challenge with Diet Coke and the mood change is profound. The next day I was depressed, despondent and my husband said it was like turning off a light. – by email