1. Caloric Restriction: Less Is More
Caloric restriction (CR), which involves reducing calorie intake without causing nutritional deficiencies, has been widely studied in animals. However, human studies have also begun to yield interesting results. In the U.S. CALERIE Trial, a 25% reduction in calorie intake over two years produced beneficial effects on metabolic health, including improvements in blood pressure, glucose levels, and cholesterol.
For example, a recent study conducted by researchers at the National Institute on Aging found that caloric restriction improved cardiovascular health in older adults by reducing inflammation and enhancing endothelial function—an essential factor in vascular health.
That said, long-term adherence may be challenging, and evidence on CR’s ability to extend human lifespan remains limited.
2. Intermittent Fasting: Benefits for Metabolic Health
Intermittent fasting (IF) is a dietary strategy that alternates periods of eating with periods of fasting. Instead of reducing total calories, IF focuses on when you eat. Common approaches include 16-hour fasts with an 8-hour eating window, or 24-hour fasts on alternate days.
Interest in intermittent fasting has grown due to its potential benefits for metabolic health and longevity. Animal studies show that IF helps reduce body fat, improve insulin sensitivity, and promote autophagy—a cellular process that clears and recycles damaged components. At the molecular level, IF activates longevity-related pathways such as sirtuins and AMPK, which support cellular repair and metabolic health.
In humans, while research is still emerging, early trials suggest that IF may help with weight management, reduce cardiovascular risk, and improve brain function. However, long-term effects on human longevity remain unclear.
Figure 1. Hypnogram of a healthy adult
3. Ketogenic Diets: Using Fat as Fuel
Ketogenic diets drastically reduce carbohydrate intake and increase fat consumption, inducing a metabolic state called ketosis where the body burns fat instead of glucose. They are effective for treating certain neurological conditions, such as epilepsy, and are often promoted for weight loss.
Regarding aging, some studies suggest that ketosis may have neuroprotective effects by reducing inflammation and improving cognitive function in animal models. However, long-term effects on human longevity are uncertain. Keto diets can also be difficult to maintain due to restrictions on carbohydrate-rich foods such as fruits, vegetables, and whole grains, potentially leading to nutritional deficiencies if not properly managed.
Although proponents argue that ketogenic diets may delay aging by reducing insulin spikes and improving metabolic health, more research is needed to validate these claims in humans.
Figure 2. Physiological decrease in melatonin production with age
4. Time-Restricted Feeding (TRF)
Time-restricted feeding (TRF) is an eating pattern that limits food intake to specific hours of the day, often 8–12 hours. This approach aligns with the body’s natural circadian rhythm. TRF overlaps with certain intermittent fasting practices.
Preliminary studies show that TRF may improve glucose regulation, reduce abdominal fat, and enhance metabolic health. It may also help protect against chronic age-related diseases such as obesity and cardiovascular conditions.
However, although animal findings are promising, evidence in humans is still limited. More research is needed to confirm whether TRF has significant long-term benefits and a direct impact on aging.
5. Protein Restriction and Specific Amino Acids: Less Is More… or Not?
Protein restriction reduces protein intake to potentially slow aging. Some research suggests that lowering intake of certain amino acids—such as methionine—activates longevity pathways, including sirtuins, which play roles in cellular repair and metabolism.
Animal studies show that protein restriction may extend lifespan and delay age-related diseases. However, in humans, excessive protein reduction can lead to loss of muscle mass and weakened immune function—counterproductive for overall health.
Current evidence suggests that a balanced protein intake is the best approach for healthy aging, rather than extreme restriction.
6. The Mediterranean Diet: A Balanced Approach to Longevity
The Mediterranean diet—rich in fruits, vegetables, whole grains, fish, olive oil, and nuts—has long been associated with longer and healthier lives. Rooted in traditional eating habits from regions such as Greece and Italy, it has well-documented benefits for cardiovascular health, lowering the risk of heart disease, stroke, and certain cancers.
Recent human studies reinforce these findings. The PREDIMED Trial conducted in Spain showed that participants who followed a Mediterranean diet—supplemented with either olive oil or nuts—had a significantly lower risk of cardiovascular events. They also exhibited improvements in inflammatory markers, which are strongly linked to accelerated aging.
7. Nutrition and the Activation of Longevity Pathways
A key strategy in anti-aging nutrition is prioritizing foods with high nutrient density—those rich in micronutrients, antioxidants, and bioactive compounds per calorie—and that also activate cellular longevity pathways. Nutrients such as resveratrol (grapes, berries), fisetin (strawberries, apples), sulforaphane (cruciferous vegetables like broccoli), and quercetin (onions, capers) have shown in preclinical studies the ability to modulate key longevity pathways, including sirtuins (SIRT1), AMPK activation, and mTOR inhibition.
These pathways regulate essential processes such as cellular repair, autophagy, protection against oxidative stress, and metabolic regulation—all central to slowing biological aging. Diets based on whole foods, colorful vegetables, spices, and healthy fats not only provide these compounds but also reduce inflammatory load and improve mitochondrial function, translating into greater cellular resilience and long-term quality of life.
Conclusion: A Balanced and Personalized Approach
Although anti-aging diets are gaining attention, human studies are still limited and results are mixed. While approaches such as caloric restriction or intermittent fasting may support metabolic health and longevity, their definitive effects on aging remain unclear.
The most effective strategy continues to be a balanced diet rich in nutrients, fiber, healthy fats, and high-quality proteins—combined with regular exercise and overall healthy habits. If you decide to try any of these dietary approaches, it is advisable to consult a healthcare professional to ensure it aligns with your needs and does not compromise your well-being.
Article written by
Dr. Clara Font Bernet
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Tinsley, G. M., & La Bounty, P. M. (2015). Effects of intermittent fasting on body composition and clinical health markers in humans. The New England Journal of Medicine
Estruch, R., et al. (2013). Primary Prevention of Cardiovascular Disease with a Mediterranean Diet. The New England Journal of Medicine
