7-Day Protein-Modified Fast - All the Benefits of Fasting W/Out the Risk of Muscle Loss? Human Study Says...
|Lean wild salmon would be a good protein source for a PSMF regimen.|
Matthew Furber and his colleagues from the GSK Human Performance Lab and the University of Hertfordshire and the Anglia Ruskin University were recently able to proof that this special variety of fasting will not only help you shed body fat at a low risk of significant lean mass declines, it will also have profound health benefits.
As the authors highlight, the past decade of research has demonstrated quite conclusively that a hypocaloric high fat/low carbohydrate (HF/LC) diet can up-regulate transcriptional markers of mitochondrial biogenesis; accordingly, this is what the scientists based their subjects' diets on.
|Figure 1: Macronutrient comp. of the diets (for both, the EM = maintenance +ER = calorie restricted diets | Furber 2017)|
Ok, I know this is not a "fast", but I stick to the term, 'cause the authors use it
Participants visited the laboratory on 3 occasions each separated by 7 days. On each visit body composition, resting metabolic rate and a muscle biopsy from the vastus lateralis was collected. Prior to visit 1 and 2, the subject simply consumed their habitual diet, which thus served as a control. Between visit 2 and 3, the intervention diet was consumed continuously for 7-days.
|Figure 2: The scientists observed increases in AMPK, Sirt1+3 and PGC-1a, proteins that mediate the health benefits of fasting and, compared to the high-CHO fast, a sign. reduced lean mass loss + slightly enhanced fat loss (Furber 2017).|
AMPK, PGC-1α, SIRT1 and SIRT3 mRNA expression was observed - a slightly greater increase than in the other groups, that is (p < 0.05).
Furthermore, no difference in lean mass (LM) loss was observed between the PRO-ER and CHO-EM groups, despite ~30 % reduction in calorie intake - and that's just what the many N=1 reports on the results of short-term PSMF regimen say, as well.
- Furber M, Anton-Solanas A, Koppe E, Ashby C, Roberts M, Roberts J. "A 7-day high protein hypocaloric diet promotes cellular metabolic adaptations and attenuates lean mass loss in healthy males." Clinical Nutrition Experimental (2017), doi: 10.1016/j.yclnex.2017.05.002.