Out of the underlying research from that study that I read, This One was (IMO) the gem. It needs to be read properly as the picture is complex, but the take-home that people should stop and think about is :
Therefore, a realistic increase in the LC/HP score by five units (corresponding to, e.g., an increase of protein intake by about 15 g/day and a decrease of carbohydrate intake by about 50 g/day) was associated with a 22% increase in overall mortality (CI, 9–36%).
"The vibe" is that increasing protein and fat from animal sources (ie. steak) at the same time as reducing intake of fruit/vegetables is detrimental to your health (Duh!). The absolute protein numbers, in an Australian context, were really low - the mean was only 76g/day!
PS - my "fat mate" has gone "low carb" because the cycling pod casts are promoting it. Which (as far as I can tell) means he's given up muffins etc. at the coffee stop and is eating less fried chips on take-away nights. He has lost 4kg (~4.5%), but I think that's more about an improved diet quality than "less carbs". But he's happy to tell me he's gone low carb.