dominic wrote: Is there any counter-evidence? If we go lower and risk loss of FFM (bad, presumably) do we also encourage autophagy (good, presumably)?
http://www.ncbi.nlm.nih.gov/pmc/article ... /table/T2/ lost less than 1 kg of FFM on average, with 20% protein on modified ADF with 20-30% of TDEE on fast days. This study had reductions in both systolic and diastolic BP. (Not sure I've seen this one before). Impedance analysis of body composition.
http://ajcn.nutrition.org/content/81/1/69.long is true ADF (zero calories hence zero protein alternate days) and showed a loss of FFM by DEXA of 0.6 kg.
"FFM decreased slightly in all diet groups, without differences between diets" according to the group which published the paper in the OP, in a separate paper at
http://www.ncbi.nlm.nih.gov/pubmed/22935440. Isotope dilution used for body composition - FFM was calculated by dividing total body water by the hydrating factor 0.73.
A short period of true ADF with no significant weight loss or body composition change reported at
http://jap.physiology.org/content/99/6/ ... nsion.html using DEXA showed a ~1 kg reduction in mean FFM
Varady's modified ADF uses <30g protein per day on "fast" days
http://ajcn.nutrition.org/content/90/5/ ... nsion.html which resulted in " Fat mass decreased (P < 0.01) by 5.4 ± 0.8 kg after 8 wk of diet, whereas changes in fat-free mass were not significant (−0.1 ± 0.1 kg) " using impedance measurement.
Similarly Varady reports "fat mass decreased by (P<0.0001) 5.4±1.5 kg and 4.2±0.6 kg, while fat-free mass remained unchanged (ADF–HF: 1.1±1.3 kg; ADF–LF: 0.5±0.7 kg)." in modified ADF 25/125 % of TDEE at two fat levels. DEXA analysis.
http://www.ncbi.nlm.nih.gov/pubmed/23612508While I agree that high protein (up to 35% of dietary intake) is beneficial to fat loss in prolonged calorie reduction my opinion is that the ADF trials do not provide an evidence base for its use and I fall back to the Horizon documentary and "go go mode" and all that where eating less protein was a key part of the argument for better
health outcomes.
Of the published trials of IF only Harvie's 2-day low carb diet uses more protein, around 50g per day on restricted days.