Hello Wa'il,

answering your question "which book added that?"...

the latest books on zone strategies for enhanced bodyfat loss and overall health are (besides The Fat Flush Plan by Ann Louise Gittleman)

The Omega Rx Zone (2002) by Barry Sears, Ph.D.

Fat Wars (2002) by Brad J. King, M.S., M.F.S.

The Ultimate Fat Burning Diet Primer (1999) by Paul Crane

for variants of the zone eating, (various proportions of carbs to protein, 30/50, 50/30, 40/40, etc. all moderate fat, of course) with quizzes which will help one determine their own 'zone' see

Hollywood's Healthiest Diets (1999) by Tony Perrone, Ph.D.

best wishes
Mila