New research suggests that while exercise helps ward off chronic ailments such as obesity, diabetes, and heart disease that can shorten a normal lifespan, only cutting calories appears to slow down the primary aging process.

Investigators at Washington University in St. Louis have found that eating a low-calorie, nutritionally balanced diet lowers concentrations of a thyroid hormone known as T3, which controls body temperature, cell metabolism, and it appears the production of free radicals – all of which are important aspects of aging and longevity. Calorie-restriction also decreases levels of the inflammatory protein tumor necrosis factor (TNF)-alpha.

The combination of lower T3 and TNF levels may slow the aging process, Dr. Luigi Fontana and colleagues report in the Journal of Clinical Endocrinology and Metabolism.

In earlier work, Fontana’s group found that both cutting back on calories and exercising protects lab animals from heart disease, diabetes and obesity. However, only cutting back on calories increases the animals’ lifespan. This hints that leanness is the key factor in preventing age-related disease, but that reducing the amount of calories consumed is needed to slow down aging.

In the study, Fontana and colleagues compared thyroid hormone levels of 28 adults consuming a self-imposed calorie-restricted but nutritionally packed diet for 3 to 15 years, with that of 28 sedentary adults consuming a typical Western diet and 28 endurance athletes who were also consuming a Western diet.

The calorie-restricted group consumed about 1,800 calories per day, whereas those on the Western diet took in about 2,700 calories per day.

The researchers observed reduced T3 concentrations only in the calorie-restricted group. Levels of two other thyroid hormones – T4 and TSH – were normal, indicating that the calorie-restricted group was not suffering from thyroid disease called hypothyroidism.

Interestingly, according to the team, body fat levels did not affect T3 levels. This is a key finding, they say, because it suggests that decreased T3 levels are likely related to calorie restriction not changes in body fat.

T3 concentrations were 30 percent lower in the calorie-restricted eaters compared with the exercisers, even though percent body fat was similar between the two groups.

The difference in T3 levels between the calorie-restricted group and the exercise group is “exciting,” said Fontana, “because it suggests that calorie restriction has some specific anti-aging effects that are due to lower energy intake rather than to leanness.”
– Journal of Endocrinology and Metabolism

Dr. Keith and Laurie Nemec’s comments on Low Calorie Diet Tops Exercise for Staying Young.

This fascinating study showed very simply what affects health, healing and aging. The new research showed that although exercise does help very much so, decreases chances of chronic ailments, such as obesity, diabetes, and heart disease, that can shorten normal life span, only reducing calories, the term is called calorie restriction, appears to slow down the primary aging process. What was found by the researchers, was that as calories are reduced in this study, averages 2700 for a standard American and in this study they decreased it to 1800 calories per day, but nutritionally balanced 1800 calories, as opposed to the western diet which is averaging 2700 calories per day.

What they showed was the indicators of a thyroid hormone T3, which controls body temperature, cell metabolism and it also appears to effect the production of free radicals, which is a very important part of aging and longevity. Calorie restriction lowered the T3 concentration and also calorie restriction decreased the level of inflammation which is measured in an inflammatory protein called Tumor Necrosis Factor Alpha. The combination they found of lowered T3 and TNF levels, slows the aging process. Interesting in this study confirms what researchers have found over years of research: the only thing that will increase longevity of everything ever studied, is calorie restriction and as this study confirmed again, part of this is because the thyroid decreases in function but not in an unhealthy way. The study showed it did not send a person into hypothyroidism, but in a healthy on the low side of optimal range. What this does is it slows the metabolism a bit so the body actually ages less rapidly. Past studies have also shown that calorie restriction decreases the insulin secretion by the body which also is a major factor in aging.

What is the easiest way for you to start decreasing calories, or eating a calorie restricted diet? Simple, eat the diet that God designed you to eat which is a living/raw plant based diet. The more vegetables, sprouts, seeds, nuts, avocados and whole grains that one eats in the non cooked state, the calories go down and the nutrients go up. This is what you see in nature. Elephants, Zebras, all animals in nature that eat a living plant based diet, you will not see fat animals in nature. There is no fat because there is no cooked food consumed. Cooking destroys enzymes and increases weight gain by increased calorie intake. Animals in the wild never deal with this because whether they are plant eaters or animal eaters, they eat it in the living state. So, when we take that role, when we eat a more vegetables, sprouts, avocados, seeds and nuts, we’re going to naturally be doing a calorie restricted diet and we’re going to be very full with the concentration of nutrients not only from the protein and fat from seeds and nuts and avocados, but from the fiber.  Fiber fills us and that full feeling causes us to decrease eating, or to stop eating.