Caloric restriction is the closest thing there is to a dietary silver bullet. In test after test it improves health markers across the board in every corner of the biological kingdom.
This discovery led to further interest in the causal link between caloric restriction and good health. Is it the reduction in calories itself that does the good things, or is there a more granular dietary practice within the act of caloric restriction that promotes longevity?
A decent amount of evidence suggests caloric restriction all by itself is responsible for its effects. This is good and bad news, since caloric restriction is simple in practice but not very fun and takes some of the “Joy de Vivre” out of eating.
However, a few studies suggest that caloric restriction is not effective if nutrients are also sacrificed. It’s also been found that many of the benefits of caloric restriction are mimicked if only carbohydrates are reduced.
In particular, there’s a strong link between the onset of cancer and high carbohydrate consumption. “Carbs and Cancer” has become a catch phrase within the health industry because it appears their excessive consumption causes all the nasty stuff that caloric restriction does away with. A high carbohydrate diet results in high insulin levels within the body, and excessive insulin promotes excessive cell growth by disrupting a mechanism called the insulin/IGF-1 cell signalling pathway. Malignant cells also require large amounts of glucose (sugar) for their metabolic needs, and are usually unable to metabolize fat and protein.
Low carbohydrate diets are also being used in nutritional therapy to treat a variety of lifestyle diseases such as narcolepsy, fatty liver disease, acid reflux disease, and epilepsy.
One caveat against low-carbohydrate diets is their effects have not been measured over long periods of time. However, studies that measure the effect of low carbohydrate intake for periods longer than one year suggest the diet has enduring effects on metabolic regulation, body-weight, and insulin levels.
While moderate carbohydrate intake appears to be good for your health, a diet that’s low in carbs might not provide adequate amounts of calcium and fiber, both important nutrients. Dairy products and vegetables are good substitutes.
Of course, with any of these sorts of diets, the quality of the food you eat has a large impact on how enduring the health benefits will be. Lean beef > jerky, soy milk > craft cheese, etc.
But processed grain is a new phenomenon in our dietary regime, and our bodies have not had the time necessary to figure out how to process more than 200g of carbs a day without lingering side effects.