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Be Healthier and Live Longer by Occasionally Eating Less

Researchers find fewer calories every so often can slow down the aging process.

Key points

  • Your biological age better reflects your health status than your chronological age.
  • Periodically cutting calories can slow down the biological aging process.
  • A new study shows that a diet mimicking the effects of fasting can reduce health risks and increase lifespan.
Source: Victoria Shes / Unsplash
Vegetable soup is included in a fasting diet.
Source: Victoria Shes / Unsplash

Decades of animal testing led to the discovery that time-restricted eating, intermittent fasting, or near-fasting—cycling between periods of eating less or nothing followed by periods of eating as much as you want—helps mice age better and live longer. Human testing has now shown similar results, and researchers at the Longevity Institute of the Leonard Davis School of Gerontology at the University of Southern California have been able to predict the significant risk reduction and life-extending power of periodically mimicking a fasting diet.

According to their study, published in the scientific journal Nature, the potential health benefits gained from moderate, intermittent near-fasting are quite impressive. By periodically following a fast-mimicking diet, they say, it’s possible to delay the biological or physical aging process and have an extended disease-free period of life.

Out With the Old, In With the New

Theoretically, the fast-mimicking diet destroys damaged cells that cause health issues like inflammation and cancer while also protecting healthy and new cells from similar damage by slowing down biological aging. (Your biological age is more representative of your health risks and longevity than your chronological age.)

The fast-mimicking diet is a five-day (per month), plant-based diet low in calories and protein, followed by a normal diet supporting new or more functional cell growth. The fast-mimicking diet for study participants included vegetable-based soups, energy bars and drinks, chip snacks, tea, and a high-level vitamin, mineral, and essential fatty acid supplement. The total calories are 1,100 calories for the first day and 700 calories for days two to five. The food and supplements were boxed daily and presented to participants, who could choose when they ate throughout each day.

Study participants included 100 men and women ages 18 to 70 and excluded anyone with major physical health conditions or mental illness. The researchers found that just three monthly cycles of the fast-mimicking diet reduced biological aging by an average of two and a half years. Study participants also experienced weight loss, total body fat loss, reduced abdominal and liver fat, lower blood pressure, reduced triglycerides and cholesterol, lower fasting glucose levels, and reduced insulin resistance, especially in those with higher rates of these risk factors at the beginning of the study.

Be Healthy, Be Safe

Using data from this study, the researchers were able to predict the overall disease risk reduction and life-extending benefits of a fast-mimicking diet based on the assumption that participants participate in three-month diet cycles three times every year. They could predict a possible decrease in biological age of approximately 11 years over 20 years.

Previous animal and human studies have found that a periodic fast-mimicking diet that meets basic nutritional needs can help alleviate symptoms and improve the metabolic health of patients with Alzheimer’s disease, diabetes, cancer, and multiple sclerosis. While ongoing calorie restriction alone can help reduce weight and control disease risk factors, it’s well-documented how difficult it is for most people to maintain a low- to very low-calorie diet for any significant time. For many, a periodic fast-mimicking plan may provide the same, if not more, risk-reducing benefits while less burdening the individual.

Larger and more comprehensive studies are necessary to determine safety and potential side effects for all ages and health conditions before health professionals can generally recommend fast-mimicking diets. Regardless, as with any diet plan or big change in dietary habits, it is especially important to speak to your physician or healthcare provider before starting any new or restrictive plan, regardless of age, fitness level, or current state of health.


Brandhorst, S., Levine, M.E., Wei, M. et al. Fasting-mimicking diet causes hepatic and blood markers changes indicating reduced biological age and disease risk. Nature Communications. 20 Feb 2024: 15; 1309.

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