At this point in science, the only proven means to slow the aging process (at least in laboratory animals) is chronic caloric deprivation. Indeed, animal studies have shown repeatedly that decreasing caloric intake long term can dramatically slow down the ever-ticking aging clock. Scientists surmise that the key mechanism is that reducing calories slows metabolism by reducing levels of the thyroid hormone T3. Less T3 means less tissue aging.

While studies to test this hypothesis in humans are on-going, a first-of-its-kind, initial report lends credence to this exciting possibility. Reporting in the June edition of Rejuvenation Research, scientists found that T3 hormone levels do decrease in human subjects who shave back a bit on their daily calories. In this study, 1 group of subjects cut their daily calories by 300 – 500, while a second group ate their regular diet, but increased daily exercise. A third (control) group made no changes. At the end of the 1 year study those on the calorie-restriction and exercise plans both lost fat mass, but only those in the calorie-restriction group had lower levels of T3.

A few years back I attended a scientific meeting where a researcher showed a large photo of an elder rhesus monkey subjected to life-long, “healthy” caloric deprivation right next to the photo of a rhesus monkey of the exact same chronological age fed a typical monkey diet – the visual contrast was simply astounding and in people terms was roughly equivalent to the difference between looking at a picture of a 35 year old next to a 60 year old.

While we wait for definitive studies on the anti-aging effects of calorie restriction in humans, I can assure you that cutting back on your calories can definitely lower your risk of our most common causes of death including heart disease, cancer, and diabetes. As further motivation, consider that over-indulgence likely accelerates the aging process – scary.