The paper you cited references three other papers. The first paper just throws out an estimate with no source or data for it, just a figure. That figure is also

The paper you cited references three other papers. The first paper just throws out an estimate with no source or data for it, just a figure. That figure is also not in mg/kg just total dietary intake. Honestly the figure itself is believable as it claims 0.3g to 1.0g per day which works out to 4.3mg/kg to 14.3 mg/kg for a 70 kg person. The second paper isn't listing MSG or even just free glutamate, it's listing all glutamate content which as you pointed out in another comment, is not comparable. The third paper cited appears to be where they got their wildly wrong claim of 50 mg/kg to 200 mg/kg from but this literally just cites the first two papers. I'm assuming they just converted the glutamate figures in the second paper and assumed all of that was MSG. Either way the claim that average daily intake of MSG is between 50 mg/kg and 200 mg/kg is just flat out unfounded and wrong. The very first source they cite lists a figure less than 1/10th that amount and obviously does not support their claim. And keep in mind, a 150 mg/kg dose for an average person is 10.5 g, that's over 20x the recommended serving size. [1] https://academic.oup.com/jn/article/130/4/1058S/4686672 https://academic.oup.com/jn/article/130/4/1058S/4686672 [2] https://pdfs.semanticscholar.org/9f51/b5f34954560f02b0c01eb9749a78cbf4536e.pdf https://pdfs.semanticscholar.org/9f51/b5f34954560f02b0c01eb9... [3] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3606962/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3606962/