Figure from: Colman RJ, Anderson RM, Johnson SC, et al. Calorie Restriction Delays Disease Onset and Mortality in Rhesus Monkeys. Science. 2009;325:201-204.

Calorie restriction has been an increasingly discussed topic of conversation in the nutrition world, especially as it related to the aging demographic. As we age, our bodily mechanisms, including metabolism of nutrients, begin to dwindle. Aging adults face greater risk of chronic disease, such as cardiovascular disease, stroke, and cancer, just to name a few. But, what if there was a way to REDUCE your risk of aging-related complications? Dietitians are always saying that it’s never too early to begin a healthy eating regimen, and we couldn't be more right. However, there is a specific WAY of eating, called calorie restriction, that may provide more accurate results to longevity of life and increased health span.

Truth be told, most of the research done in this area of nutritional science is with animals. Why? Because animals die faster. With this said, we can assess the lifespan more closely and with more participants (i.e. animals) than humans, who live decades longer.

So what is "calorie restriction?" For now, calorie restriction is characterized by a 10-40% reduction in intake of a nutrient-rich diet. Keeping the amount of nutrition consumed while reducing only caloric intake could mean reduction of inflammation throughout the body. You might think, "I’m not inflamed," but this might not be true. Inflammatory markers increase when you are overweight, have cardiovascular issues, have kidney issues, and even type II diabetes. The mechanisms behind the action of calorie restriction are numerous, including nutrient-responsive signals in the body; effects on genes, hormones, and neurons; and the reduction of oxidative stress, therefore decreasing inflammation and the onset or progression of chronic diseases associated with aging. Oxidative stress happens when there is an imbalance of toxins in the body that are not able to be released (note: "cleanses" do not resolve oxidative stress!).

Calorie restriction has been seen, through these various ways, to cause LESS damage to DNA, thus resulting in an increased healthy span of life. Animal and human studies have suggested significant changes in all of these areas; however, additional human research needs to take place in order to truly say that this could work for people. At this time, there are limited to no clinical conclusions that can be drawn from the current body of research. Modest calorie intake and weight loss are already well-established clinical recommendations used to promote health and reduce chronic disease risk. Being too thin may result in other complications - any weight loss plan should be discussed prior to initiation with a dietitian or physician. Reducing caloric intake for most people may result in positive outcomes, however, intentional caloric restriction is not adequately well founded to provide the basis for public health or personal recommendations.

Happy Eating!