Sorry link doesn't work for me, but funny you should mention baby and diet, I have experienced that first hand recently.
My grandbaby was born last September 21. He was totally breast fed. He was colicky, throwing up, not sleeping well, crying, screaming, etc. They said, "Don't worry, when he is three months all that will change." Then it was four months, five, six, seven and he was still hell on wheels. Did I mention he and his Mom and Dad live in my house? You couldn't hold him without him arching his back and squirming all around.
My lovely daughter-in-law then eliminated all milk products from her diet. Voila! We have a perfect angel (as angelic a baby can be) who now naps, no longer throws up milk, and smiles at us.
I know this little story is anecdotal as to a link between diet and behaviour, but I have experienced a behaviour change too with a change in diet. I wouldn't have believed it myself.
As my genius brother says, "What you don't eat can't kill you."
That was my baby girl I was talking about. I was in my organic gardener, La Leche League stage. I thought about what I was eating/drinking and didn't have any exposures I could locate. Gave up caffeine (and milk in the coffee) before she was born, because she'd kick me for hours. Goofed once and drank a "real" cup of coffee - we were up till 3 or 4 with a very unhappy girl.
We never medicated her for the ADHD, because she was happy, everyone loved her, and she made A's and B's. Found out later that she was mad because she couldn't be a crossing guard as long as she made "U"'s in conduct, but I didn't know it then.