Intermittent Fasting

Introduction

The simultaneous improvement of health and physique is often sought through exercise, however, sustained fasting can achieve the same goal without expending time or money. A few dietary regimes have been devised to achieve mesh the benefits of fasting with the contemporary lifestyles.

Caloric Restriction (CR) constrains the quantity of consumption to below one's metabolic rate.

Ketogenic diets - such as the Atkins diet, a low-glycemic index diet, and a Medium Chain Triglycerides (MCT) diet - constrain the set of consumed foods to only those with low glycemic loads. This regime maintains ketogenesis - the metabolic state during fasting - despite regular eating. These diets are clinically useful (especially in children) to treat or cure neurological abnormalities1, yet, they are often deficient in calcium and B-complex.

Intermittent fasting (IF), in contrast to the aforementioned fasting diets, constrains mealtimes to certain hours or days. This regime improves health to an equivalent or greater degree than ketogenic diets2 and caloric restriction3,4 without compromising the quantity or identity of one's diet, and while notably maintaining nutritional status and muscle mass5. These diets are moreover considered a safe6 method of alleviating inflammation, optimizing physiology7, increasing cellular resilience8 to toxicity, and slowing metabolic ageing9.

Intermittent Fasting

A few IF diets can be practiced. The century old10 5-2 diet11 consists of 2 non-consecutive fasting days with 5 calorically normal days each week. This diet has extended the longevity of animals10. Hour-restricted IF diets specify windows of time each day in which consumption is permitted, which is famously exemplified by Islamic Ramadan where consumption is permitted only when the sun is not out. This religious fast has been noted to improve lipoprotein concentrations12,13, albeit at the sacrifice of sleep14. Other windows of time may be selected, such as the morning/midday15 that better synchronizes with the circadian rhythm and improves the microbiota profile16. The health benefits of IF are enumerated in the following sub-sections.

Diabetes and Metabolic Syndrome:

The metabolisms17 and resting glucose and insulin concentrations4,5,18 of diabetics were improved by time-restricted IF19, which was augmented by the combination of CR15,20. IF and CR in combination is an effective method of specifically reducing visceral fat mass21, which is a prominent risk factor for diabetes and metabolic syndrome.

Cardiovascular tone:

IF decreases resting blood pressure and heart rate22 while improving physical recovery from heart attacks8. The cardio-protective benefits are supposed to originate from the increased production of vascular endothelial cell growth factor (VEGF)23.

Brain and neurology:

IF strengthens nerves against death from strokes and degenerative diseases like dementia24, Alzheimer's disease25, cognitive decline from age or infection24, epilepsy2 and traumatic brain injury1 (comparable to the results of ketogenic diets), and Huntington's disease11. The neuroprotective benefits of IF may derive from increase production of Brain-derived neurotropic factor (BDNF)23, which stimulates neurological growth and recovery.

Conclusion

The systemic benefits and noted safety of IF suggests that this dietary practice may be a convenient means of improving health and wellbeing without compromising comfort foods.

References

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