@Austin_Baraki - posting this topic per our chat on SteadyMD.
3 years ago, as a 43 y/o skinny runner, I embraced strength training to build muscle mass, get strong, and invest in my long term health span. I changed my diet “To Be a Beast”, gained 40 lbs, and have hit lifetime PRs. Training has become a cornerstone habit for me, but I recently read Dr. Valter Longo’s book, The Longevity Diet, and that has raised questions and concerns regarding my current diet, protein intake, and impact on longevity and health span.
Longo’s main points are:
“High” protein intake activate the growth hormone receptor, increases levels of insulin and IGF-1, which increases diabetes and cancer risk
Proteins and the amino acids associated with stimulating muscle protein synthesis, like leucine, can activate TOR-S6K, a set of genes that accelerate aging.
Based on his research, he advocates a diet limited to no more than 0.31-0.36g of protein/lb of body weight, with minimal animal (non-fish) protein, avoiding the amino acid profile typically advocated for MPS.
For individuals age 65 or older, he acknowledges the sarcopenia risk and advocates increasing protein to maintain muscle mass.
This creates a dilemma in my training/diet mindset. I want to continue to train and improve strength, but I’m not a competitive powerlifter. I’ve settled in to a stable body weight and want to maximize my strength and muscle mass within that range - and new PRs are icing on the cake. But I’m concerned that my current dietary approach of 1g protein per lb of bodyweight is creating increased mortality risk and is in conflict with optimal longevity/health span aspirations.
My questions:
Do you agree with Longo’s research and recommendations or have you identified exceptions/caveats for the strength training population vs general population? For example, is there research that indicates that athletic/strength trained populations can tolerate more than 0.36 g protein/lb body weight without the increased risk?
What about taking a dietary approach focused on maintaining body weight and muscle mass? What is the minimum amount of protein per/lb of BW is necessary to maintain muscle mass? Do we need the same amino acid profile to maintain vs grow muscle mass, or will vegan/plant-based/pescatarian protein sources/amino acid profiles be sufficient for maintenance?
Is dietary cycling a viable approach? For example, what if I went through periods of high-protein diets to support strength/muscle mass gains, followed by periods of maintenance protein levels + the periodic 5 day fast-mimicking diet Longo advocates?
Is this ultimately an either/or decision, and a powerlifter/strength training diet is not reconcilable with a longevity diet?
Thank you very much for your help and guidance on this, and all the great work you do.
The research does not currently show that higher protein intake is associated with increased all-cause mortality, diabetes, or cancer when correcting for body mass.
Longo’s own research (Low Protein Intake is Associated with a Major Reduction in IGF-1, Cancer, and Overall Mortality in the 65 and Younger but Not Older Population - PMC) does not support the first bullet point. Rather, effect sizes were either non existent or very small for diabetes and cancer before correcting for total calorie intake and adiposity. They also didn’t find a dose-dependent protein:disease relationship outside of arbitrarily made cutoffs that are not clinically meaningful. This complicates their hypothesis. The in vitro data notwithstanding, I don’t think we can agree with Longo’s stance here.
Acceleration of aging doesn’t really mean anything to me. Additionally, activation of the mTOR pathway via resistance training and dietary protein ingestion for muscle remodeling/building are not the same as eating protein when sedentary. 1000’s of hormones, genes, etc. are manipulated here so drawing conclusions from sedentary adults and protein intake is difficult for our population.
Our recommendation is to consume ~1.2-1.6g/kg protein bodyweight per day. Individuals who are losing weight, are very lean, and/or who are training very hard can push this up to 3.1g/kg per day. I do not think you should fast for extended periods of time or cycle dietary composition for improved health unless you are overweight/obese and this helps you normalize your body fat.
I do not think a diet that supports strength training is at odds with a health-promoting diet.
There is a documentary featuring Dr Longo called Eat, Fast and Live Longer done by the BBC. It explicitly mentions protein as being the cause of telomer shortening. However, it doesn’t recommend a low protein diet. It also discusses some of the genetics behind the problem with some of the research. However, most of what Dr Longo refers to as cellular aging is just a reference to telomer length.
However, there are other things to consider in regards to cellular aging and telomeres.
I would assume based on the research that as long as you are periodically cutting and maintaining a healthy weight you are fine.
I also have his book, and noticed that Longo is selling a diet, isn’t there a conflict of interests there for him? My opinion is that the bodybuilding champions never seem to die of cancer, they die of old age, and sometimes from heart disease. If you look at Professor Longo he could do with working out to the max and eating more protein, is he waiting to die?