New Study: A Ketogenic Diet May Reverse Biological Aging in People with Obesity

---

Source: Nutrients, March 18, 2025
Study Title: “Epigenetic Aging Acceleration in Obesity Is Slowed Down by Nutritional Ketosis Following Very Low-Calorie Ketogenic Diet (VLCKD)”

We know that obesity is linked to a higher risk of chronic diseases, but a groundbreaking new study suggests it may also accelerate the aging process at a molecular level. More encouragingly, the research shows that a specific type of ketogenic diet might be able to slow—and even partially reverse—that acceleration.

What is “Biological Age” vs. “Chronological Age”?

Your chronological age is simply how many birthdays you’ve had. Your biological age reflects the true health of your cells and tissues. Scientists can now estimate biological age using “epigenetic clocks”—tools that analyze DNA methylation patterns to determine if your body is aging faster or slower than expected.

The Key Findings: Obesity Accelerates Aging

Researchers analyzed the blood of individuals with normal weight and those with obesity. They found that people with obesity had a significantly higher biological age compared to their chronological age.

• On average, the obesity group showed an epigenetic age acceleration of over +4 years.
• This acceleration was strongly linked to a higher Body Mass Index (BMI).
• In contrast, the normal-weight group showed a slight biological age deceleration (about -3.1 years).

Essentially, carrying excess weight appears to put your cells on a faster aging track, increasing the risk for age-related diseases.

The Good News: The VLCKD Intervention Slowed Aging

The most exciting part of the study involved a longitudinal trial where 10 patients with obesity followed a Very Low-Calorie Ketogenic Diet (VLCKD) for six months. The results were remarkable:

1. Biological Age Decelerated: After just 30 days on the diet (during the phase of nutritional ketosis), the participants showed a significant deceleration in biological age—an average slowdown of -6.1 years.
2. Results Were Sustained: This beneficial effect was maintained at the end of the 180-day intervention, with an average deceleration of -6.2 years.
3. Ketosis Was Key: The slowdown in aging was directly correlated with higher levels of β-hydroxybutyrate (β-OHB) , a ketone body produced during ketosis. This suggests that ketosis itself—not just weight loss—drives the anti-aging effect.
4. Metabolic Health Improved: The deceleration was also linked to improvements in glucose, insulin, cholesterol, and triglyceride levels.

“Our findings highlight the applicability of epigenetic clocks to monitor obesity-related biological aging… and show the potential efficacy of the VLCKD in slowing obesity-related epigenetic aging.” – The Study Authors

Why Might a Ketogenic Diet Affect Aging?

The researchers propose several mechanisms. Ketone bodies like β-hydroxybutyrate are known to have powerful effects beyond providing energy. They can:

• Reduce chronic inflammation (a hallmark of both obesity and aging).
• Lower oxidative stress.
• Influence gene expression related to longevity and metabolism.

In a previous related study, the same research group found that VLCKD led to positive changes in the DNA methylation patterns of over 700 genes involved in fat tissue function, muscle development, and neurological health.

Importantly, this effect appears unique to the ketogenic diet. The study notes that bariatric surgery, despite achieving similar weight loss, did not produce the same significant slowdown in epigenetic aging.

What This Means for You

This is the first study to show that a very low-calorie ketogenic diet may reverse the accelerated biological aging associated with obesity.

Important Caveats:

• This was a small study (10 people in the diet group). More research is needed.
• A VLCKD is a medically supervised, restrictive protocol. It is not the same as a standard “lazy keto” diet. It should only be followed under the guidance of a healthcare professional, especially for individuals with underlying health conditions.
• The study does not claim that the diet makes you “immortal,” but rather that it may slow the cellular aging process, potentially extending healthspan (the years of healthy life).

The Bottom Line

For the first time, we have evidence that a dietary intervention—specifically a VLCKD that induces nutritional ketosis—can positively alter the epigenetic clock in people with obesity. This moves us closer to the era of “precision nutrition,” where diets are chosen not just for weight loss, but for their ability to reprogram our biology and promote healthy aging.

---

Reference: Izquierdo, A.G., et al. (2025). Epigenetic Aging Acceleration in Obesity Is Slowed Down by Nutritional Ketosis Following Very Low-Calorie Ketogenic Diet (VLCKD): A New Perspective to Reverse Biological Age. Nutrients, 17(6), 1060.