Abstract
WHO projects that approximately 2.3 billion adults will be overweight in 2015. The fundamental cause of overweight is an energy imbalance between calories consumed and calories expended. Overweight is a risk factor for a cardiovascular disease. In experimental animals, numerous studies have found that dietary restriction without malnutrition prolongs the lifespans. Preliminary data indicate that this is true in monkeys, and could be true in humans as well. Fasting is a type of dietary restriction, representing the complete restriction of nutrients. It has been reported that intermittent fasting and short-term repeated fasting, in which fasting is repeatedly alternated with ad libitum feeding, is effective in increasing animal lifespans. Dietary restriction and fasting have been documented to have a preventative effect on various diseases, such as malignancy, autoimmune diseases and Parkinson's disease. Recently, we applied dietary restriction to allergy diseases in animal models, and found that atopic dermatitis and contact dermatitis were suppressed. Furthermore, in a clinical study, we offered a low-energy diet to 19 adults with atopic dermatitis during 8 weeks, and reported remarkable improvement of atopic dermatitis, which was associated with weight loss by a low-energy diet. With regard to rheumatoid arthritis, the effect of fasting followed by one year of vegetarian diet was assessed in a randomized, single-blind controlled trial. However, clinical evidence for allergic disease and autoimmune disease is still limited. Therefore, an accurate and large-scale study is necessary in the future so that dietary restriction may establish it as a treatment of atopic dermatitis and rheumatoid arthritis.
