Calorie restriction, Autophagy, Longevity, and Muscle loss
We all want a substantial amount of muscle mass and fast metabolism so that we can eat more but autophagy is what is in line with evolutionary biology.
Milos Pokimica
Written By: Milos Pokimica
Medically Reviewed by: Dr. Xiùying Wáng, M.D.
Updated June 9, 2023We want to have muscle mass as much as possible and a fast metabolism as much as we can so that we can eat more and don’t gain weight but evolutionary biology will again tell us what is healthy and it is not constant overeating on food. Animals in nature have a hard time finding food so a basic level of existence is an increased level of autophagy with intermittent fasting and calorie restriction. I am going to use a quote from the U.S. Department of Health & Human Services National Institute on Aging website:
“Since the 1930s, investigators have consistently found that laboratory rats and mice live up to 40 percent longer than usual and also appear to be more resistant to age-related diseases when fed a diet that has at least 30 percent fewer calories than they would normally consume. Now researchers are exploring whether and how caloric restriction will affect aging in monkeys and other nonhuman primates.”
We have a large number of human studies now (Fernández-Ruiz, 2017). The calorie restriction response exists in nearly all of the species tested to date and probably had evolved very early in the history of life on Earth as a mechanism to increase the chances of surviving periodic shortages. There is a difference between fasting and prolonged calorie restriction but the underlining mechanism is the same, and caloric restriction will prolong life expectancy much more than fasting periodically although even fasting periodically will have beneficial effects on longevity.
The benefits come from two main reasons. There are other benefits like:
- improved insulin sensitivity
- regulating inflammatory conditions in the body
- starving off cancer cell formation
- detoxifying
- improving eating patterns
- hormonal balancing.
However, there are two main reasons on a cellular level that underlines all of the other benefits that sprout out of these two.
Firstly, when we fast blood levels of insulin drop significantly, and blood levels of growth hormone may increase as much as 5-fold. Insulin and growth hormone play antagonistic roles against one another. When one is elevated, the other will be low. When we go to sleep we fast for 10 hours, insulin drops and HGH (human growth hormone) rises. When HGH rises we grow, especially if you are in puberty. HGH stimulates growth, cell reproduction, and cell regeneration. It is thus essential in human development.
Secondly, when we fast our cells initiate important cellular repair processes and change in which genes they express. We start to regenerate and allow for cleansing and detoxification of the body. One of the reasons why sick people have a low appetite is that there are in the process of intensive regeneration. In medical terms that regeneration is called autophagy.
In the ancient Greek word, “phagy” means eating and the word “auto” means self, so autophagy means literary self-eating. You self-eat yourself every day. When any cell in our body dies, it will not go to waste. What happens is recycling. Autophagy is a completely natural physiological method in the body that deals with the destruction of cells. It controls homeostasis or regular functioning by protein degradation and destruction and turnover of the destroyed cell organelles for new cell formation. During cellular stress (deprivation of nutrients) the process of autophagy is increased.
Autophagy has the ability to likewise also destroy the cells under certain conditions. There is a form of programmed cell death and there is autophagy-induced cell death. Two different types. Programmed cell death is commonly termed apoptosis. Autophagy is termed as non-apoptotic programmed cell death with different pathways and mediators from apoptosis. Also, this is the key to calorie restriction and fasting. If the cell is precancerous for example or damaged or mutated in any way autophagy cell death will help our body to clean itself.
After glycogen depletion, we will go into increased autophagy, and our body will lean heavily on amino acids and protein catabolism for energy creation. Amino acids will be used, and some of the muscle mass will be lost.
Moreover, it is a good thing.
Our organism is much smarter than we think. Our heart is the muscle too, but it would not be touched. First goes glycogen, then fat, then muscle then vital organs, and then we die from malnutrition. It is a brilliant plan to sustain life throughout hunger. If there is a “bad” cell and a “good” cell and some of the cells need to “go” for energy, first on the line is the bad cell. First on the line to get rid of are the parts of the system that might be damaged or old. The inefficient parts. The absence of autophagy is believed to be one of the main reasons for the accumulation of damaged cells, and this can lead to serious health complications. If we start severely damaged by chemotherapy or other toxins, fasting cycles can generate, literally, an entirely new immune system.
Exercise by itself is able to increase autophagy in a situation where autophagy already happens. The more intensive the exercise is, the more effective it will be. However, if we eat and work out the exercise alone would not be beneficial.
The fastest way to shut down autophagy is to eat high amounts of complete protein. What this will do is stimulate IGF-1 (Insulin-like growth factor 1) and mTOR (rapamycin), which are potent inhibitors of autophagy. IGF-1 (Insulin Growth Factor) is somewhat responsible for muscle growth. However, IGF-1 catastrophic side effect is cancer. It is best to limit protein to about 50 to 70 grams per day, depending on lean body mass. When we ingest large amounts of protein, our liver detects it, and the response is:
”Hey let’s grow stuff, we have all essential amino acids now.”

It starts pumping IGF-1. In the fasting state liver, GH (growth hormone) binding is decreased, so more of the GH is left in the bloodstream. In protein restriction, GH receptors are maintained but not for IGF-1.
To avoid loss of muscle during calorie restriction and dieting and to increase the benefit of calorie restriction the way to go is to do moderate resistance training. This will not prevent muscle loss but will be beneficial to some extent (Cava et al., 2017).
Another way is to avoid non-vegan food or in other words sources of “complete” protein in high amounts.
When we ingest an incomplete source of protein, meaning it lacks some of the essential amino acids, it will not signal the IGF-1 release at the same level. It is not just about the overall amount of protein consumed but also the source (Allen et al., 2002).
If you are vegan and you eat complete sources of protein like soy, you will negate the benefit. It is because of the protein profile. Vegans for instance that eat 7 to 18 servings of soy meals a day may end up with circulating IGF-1 levels that are relative to those who eat meat. That is because soy has complete protein. Some other plants have high-quality proteins too. The high consumption level of protein in the diet has other negative effects regardless. Also if your only goal is to prevent muscle mass loss during dieting and are not interested in longevity you will want to increase your protein intake.
The good news is that we can use autophagy to clean our genetic base, the bad news is that we do not do it anymore. In the past nature forced us by not providing enough resources. Today we eat regularly and even if we go hungry that will not last enough to deplete our glycogen stores.
References:
- Fernández-Ruiz I. (2017). Metabolism: Calorie restriction for healthy ageing. Nature reviews. Cardiology, 14(4), 190. https://doi.org/10.1038/nrcardio.2017.26
- Cava, E., Yeat, N. C., & Mittendorfer, B. (2017). Preserving Healthy Muscle during Weight Loss. Advances in Nutrition, 8(3), 511-519. https://doi.org/10.3945/an.116.014506
- Allen, N. E., Appleby, P. N., Davey, G. K., Kaaks, R., Rinaldi, S., & Key, T. J. (2002). The associations of diet with serum insulin-like growth factor I and its main binding proteins in 292 women meat-eaters, vegetarians, and vegans. Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology, 11(11), 1441–1448.[PubMed]
- Welton, S., Minty, R., O’Driscoll, T., Willms, H., Poirier, D., Madden, S., & Kelly, L. (2020). Intermittent fasting and weight loss: Systematic review. Canadian family physician Medecin de famille canadien, 66(2), 117–125.[PubMed]
- Zouhal, H., Saeidi, A., Salhi, A., Li, H., Essop, M. F., Laher, I., Rhibi, F., Amani-Shalamzari, S., & Ben Abderrahman, A. (2020). Exercise Training and Fasting: Current Insights. Open access journal of sports medicine, 11, 1–28. https://doi.org/10.2147/OAJSM.S224919
- Denduluri, S. K., Idowu, O., Wang, Z., Liao, Z., Yan, Z., Mohammed, M. K., Ye, J., Wei, Q., Wang, J., Zhao, L., & Luu, H. H. (2015). Insulin-like growth factor (IGF) signaling in tumorigenesis and the development of cancer drug resistance. Genes & diseases, 2(1), 13–25. https://doi.org/10.1016/j.gendis.2014.10.004
Related Posts
Do you have any questions about nutrition and health?
I would love to hear from you and answer them in my next post. I appreciate your input and opinion and I look forward to hearing from you soon. I also invite you to follow us on Facebook, Instagram, and Pinterest for more diet, nutrition, and health content. You can leave a comment there and connect with other health enthusiasts, share your tips and experiences, and get support and encouragement from our team and community.
I hope that this post was informative and enjoyable for you and that you are prepared to apply the insights you learned. If you found this post helpful, please share it with your friends and family who might also benefit from it. You never know who might need some guidance and support on their health journey.
– You Might Also Like –

Learn About Nutrition
Milos Pokimica is a doctor of natural medicine, clinical nutritionist, medical health and nutrition writer, and nutritional science advisor. Author of the book series Go Vegan? Review of Science, he also operates the natural health website GoVeganWay.com
Medical Disclaimer
GoVeganWay.com brings you reviews of the latest nutrition and health-related research. The information provided represents the personal opinion of the author and is not intended nor implied to be a substitute for professional medical advice, diagnosis, or treatment. The information provided is for informational purposes only and is not intended to serve as a substitute for the consultation, diagnosis, and/or medical treatment of a qualified physician or healthcare provider.NEVER DISREGARD PROFESSIONAL MEDICAL ADVICE OR DELAY SEEKING MEDICAL TREATMENT BECAUSE OF SOMETHING YOU HAVE READ ON OR ACCESSED THROUGH GoVeganWay.com
NEVER APPLY ANY LIFESTYLE CHANGES OR ANY CHANGES AT ALL AS A CONSEQUENCE OF SOMETHING YOU HAVE READ IN GoVeganWay.com BEFORE CONSULTING LICENCED MEDICAL PRACTITIONER.
In the event of a medical emergency, call a doctor or 911 immediately. GoVeganWay.com does not recommend or endorse any specific groups, organizations, tests, physicians, products, procedures, opinions, or other information that may be mentioned inside.
Editor Picks –
Milos Pokimica is a doctor of natural medicine, clinical nutritionist, medical health and nutrition writer, and nutritional science advisor. Author of the book series Go Vegan? Review of Science, he also operates the natural health website GoVeganWay.com
Latest Articles –
Plant Based News
-
Plant-Based Diets May Cut Cancer Risk By A Quarter, Study Shows
on August 12, 2025
-
New Report Details ‘Invisible Tsunami’ Of Pervasive Chemical Toxicity
on August 12, 2025
-
Olive Paste Pasta Salad
on August 12, 2025
-
Price Drop and Familiar Recipes Boost Consumer Interest In Vegan Eggs, Study Finds
on August 12, 2025
-
Vegans Raise £6,000 For Farming Mental Health Charity
on August 11, 2025
-
How To Make This ‘Snow White Rind’ Plant-Based Cheese
on August 11, 2025
-
Don’t Eat Avocados Until You Do This Hack
on August 11, 2025
Top Health News — ScienceDaily
- The hidden mental health danger in today’s high-THC cannabison August 12, 2025
THC levels in cannabis have soared in recent years, raising the risk of psychosis—especially in young, frequent users. Studies reveal a strong connection between cannabis-induced psychosis and schizophrenia, making early cessation and treatment essential.
- Scientists detect virus traces in blood that may unlock long COVID’s mysteryon August 12, 2025
Scientists have found protein fragments from the COVID-19 virus hidden inside tiny cellular packages in the blood of long COVID patients, offering the first potential measurable biomarker for the condition. The discovery suggests the virus may persist in body tissues long after infection, possibly explaining ongoing symptoms. While promising, the signals were subtle and inconsistent, leaving unanswered questions about whether these fragments come from lingering viral reservoirs or active […]
- Scientists discover the pancake secret that makes vegan eggs irresistibleon August 12, 2025
A study finds that people are more open to plant-based eggs when they’re part of familiar foods, like pancakes, rather than served plain. While taste and appearance still favor regular eggs, vegan eggs score higher on environmental and ethical benefits. Familiarity is the key to getting people to try them.
- Cutting sugar won’t curb your sweet tooth, scientists sayon August 12, 2025
A six-month randomized trial challenges the idea that eating more sweet foods increases a person’s preference for sweetness. Participants on diets with high, low, or mixed sweetness levels showed no changes in their sweet taste preferences, energy intake, body weight, or health markers. The study’s rigorous design suggests sweetness alone isn’t to blame for overeating, and even after the intervention, participants naturally returned to their baseline sweet intake.
- Scientists discover brain layers that get stronger with ageon August 12, 2025
Researchers have discovered that parts of the human brain age more slowly than previously thought—particularly in the region that processes touch. By using ultra-high-resolution brain scans, they found that while some layers of the cerebral cortex thin with age, others remain stable or even grow thicker, suggesting remarkable adaptability. This layered resilience could explain why certain skills endure into old age, while others fade, and even reveals built-in compensatory mechanisms that […]
- Scientists reversed memory loss by powering the brain’s tiny engineson August 12, 2025
Scientists have discovered a direct cause-and-effect link between faulty mitochondria and the memory loss seen in neurodegenerative diseases. By creating a novel tool to boost mitochondrial activity in mouse models, researchers restored memory performance, suggesting mitochondria could be a powerful new target for treatments. The findings not only shed light on the early drivers of brain cell degeneration but also open possibilities for slowing or even preventing diseases like Alzheimer’s.
- The parasite that turns off your body’s pain alarm and sneaks inon August 12, 2025
Scientists have discovered a parasite that can sneak into your skin without you feeling a thing. The worm, Schistosoma mansoni, has evolved a way to switch off the body’s pain and itch signals, letting it invade undetected. By blocking certain nerve pathways, it avoids triggering the immune system’s alarms. This stealth tactic not only helps the worm survive, but could inspire new kinds of pain treatments and even preventative creams to protect people from infection.
PubMed, #vegan-diet –
- Plant-based diets and risk of type 2 diabetes: systematic review and dose-response meta-analysison August 11, 2025
Type 2 diabetes (T2D) incidence has been steadily increasing over the past few decades. Several studies have evaluated the effect of plant-based, vegetarian or vegan diets on the risk of T2D, although their potential benefits need to be confirmed and characterized. We performed a literature search up to July 10, 2025 using the terms/keywords related to plant-based index (PDI), vegetarian/vegan diets, and T2D. We included observational non-experimental studies evaluating adherence to such […]
- Evaluating nutritional and food cost assessments: cash-register receipts may be an alternative for FFQs – accuracy and feasibility in a dietary studyon August 7, 2025
CONCLUSIONS AND IMPLICATIONS: The dietary cost of the ‘FFQ-and-supermarket-prices’ method is more strongly correlated and agreeable with the ‘cash-register-receipts-items’ method when ‘eating-away-from-home’ items are omitted, indicating that ‘eating-away-from-home’ costs are poorly estimated when using the standard ‘FFQ-and-supermarket-prices’ method. Finally, estimating energy, carbohydrates, protein, fat, calcium and iron using ‘cash-register-receipts-items’ is feasible.
- Impact of healthy and sustainable diets on the mortality burden from cardiometabolic diseases and colorectal cancer in Mexican adults: a modeling studyon August 6, 2025
CONCLUSIONS: These findings support the implementation of policies promoting HSDs in Mexico to reduce the burden of cardiometabolic and CRC mortality. Particularly, the MHSDG is a relevant strategy due to its food-system approach, local applicability and cultural alignment.
- Resolution of Chronic Urticaria in a Vegan Patient With Vitamin B12 Supplementation: A Case Reporton August 4, 2025
CONCLUSION: This case underscores the importance of considering vitamin B12 deficiency in the differential diagnosis of chronic urticaria, especially in patients adhering to restrictive diets. Addressing nutritional deficiencies can be a straightforward and effective approach in resolving chronic urticaria symptoms.
- Optimization of Almond Beverage Enriched with Omega-3 Fatty Acids by Adding Brown Flaxseeds (Linum usitatissimum L.) Using D-Optimal Mixing Diagram Methodon July 30, 2025
RESEARCH BACKGROUND: The almond beverage enriched with flaxseed is an important source of α-linolenic acid (ALA), an essential omega-3 fatty acid that the human body cannot synthesize and must obtain it through the diet. Although omega-3 fatty acids are essential for all people, this beverage is particularly beneficial for those who do not consume fish, such as vegans and vegetarians, as it is a plant-based source of ALA. Its versatility allows it to be easily incorporated into different […]
Random Posts –
Featured Posts –

Latest from PubMed, #plant-based diet –
- Probiotics and Diet Modifications: A Holistic Approach to Tackling Helicobacter pylori with the Help of the Gut Microbiotaby Tamer A Addissouky on August 12, 2025
CONCLUSION: The gut microbiota represents a promising target for enhancing H. pylori eradication. Further research on microbiota-modulating therapies like probiotics, diet, and lifestyle changes may help develop more effective, personalized treatment approaches.
- Associations of macronutrient intake patterns with accelerated biological ageing and life expectancy: Evidence from a population-based study in the UK Biobankby Peng Wang on August 12, 2025
CONCLUSIONS: This study demonstrates that the quality of macronutrient intake patterns may be more important than overall patterns in influencing biological aging and life expectancy.
- Adherence to dietary approaches to stop hypertension (DASH), Mediterranean diet, and plant-based dietary pattern with systolic and diastolic blood pressure: A cross-sectional analysisby Zahra Hassanzadeh-Rostami on August 11, 2025
CONCLUSION: No significant associations could be found between DASH, Mediterranean, and healthy or unhealthy plant-based dietary index, and blood pressure levels among hypertensive individuals.
- A simple, fast and inexpensive approach using E. coli to detect and estimate vitamin B12 content in microbial extractsby Katarzyna Hencel on August 11, 2025
Vitamin B12 is an essential micronutrient produced only by prokaryotes, and animals must acquire it from their diet. Vitamin B12 is critical for the synthesis of methionine and propionyl-CoA metabolism. In humans, vitamin B12 deficiency has been linked to many disorders, including infertility and developmental abnormalities. The growing trend towards plant-based diets and the ageing populations increases the risk of vitamin B12 deficiency, and therefore, there is an increasing interest in…
- Plant-based diets and risk of type 2 diabetes: systematic review and dose-response meta-analysisby Alberto Murciano on August 11, 2025
Type 2 diabetes (T2D) incidence has been steadily increasing over the past few decades. Several studies have evaluated the effect of plant-based, vegetarian or vegan diets on the risk of T2D, although their potential benefits need to be confirmed and characterized. We performed a literature search up to July 10, 2025 using the terms/keywords related to plant-based index (PDI), vegetarian/vegan diets, and T2D. We included observational non-experimental studies evaluating adherence to such […]
- Authentication Methods for Phytochemicals (Botanicals) in Plant Extracts and Dietary Supplementsby Santhosh Kumar J Urumarudappa on August 10, 2025
Demand for high-quality and standardized phytochemicals (botanicals) and plant extracts if rising in both the food and dietary supplement industries. Ensuring the authenticity of the plant raw materials used in botanical and dietary supplement manufacturing is an important step before processing raw materials. However, authenticating phytochemicals (botanicals) are challenging due to their unique characteristics, including geographical location, seasonal variations, environmental conditions, […]