Although the long-term effects of intermittent fasting diets is not fully understood, studies show that they could be a potential strategy for fighting the obesity epidemic in the future. The key objectives of fasting diets are promoting weight loss, preventing weight gain, and preventing regain of weight.
5:2 fasting diet concept. Image Credit: Ekaterina Markelova / Shutterstock
The 5:2 diet is a simple fasting diet regimen that involves eating anything you want for 5 days each week, while restricting calorie intake to one-fourth of normal intake on the other 2 days each week. This reduction to 25% of normal caloric intake translates to 500 calories for women and 600 calories for men on 2 days each week. However, these 2 days should not be consecutive.
The diet is flexible, and dieters can vary the number of fasting days based on their comfort level. Some people gradually move to a 4 normal days plus 3 fasting days regimen, which increases the rate of weight loss. Others move to a regimen with 6 normal days plus 1 fasting day once they have achieved the desired weight loss and target weight.
The fasting days are said to make dieters more aware of what they eat and thereby help them make healthier food choices.
Benefits of 5-2 Diet
Intermittent fasting regimens are thought to help in the repair of body cells. Regular repair of body cells plays a role in preventing ailments such as stroke, heart disease, Alzheimer’s disease, cancer, and type 2 diabetes. Studies show that intermittent fasting has helped many people return to having normal cholesterol and blood pressure levels in addition to achieving significant and lasting weight loss.
Some studies have shown that calorie restriction is associated with improved brain function and anti-aging effects, possibly due to its lowering effect on insulin-like growth factor -1 (IGF-1) levels. It is unknown whether the 5:2 diet and similar diets are sustainable over long periods of time. Such fasting regimens may take advantage of circadian rhythm to boost metabolic health. Disruptions in circadian rhythms have been associated with increased risks of diabetes, obesity, heart disease, and cancer.
Some studies on intermittent fasting in animals support claims that fasting promotes overall health. Clinical trials show that limiting calorie intake on as few as 5 days per month can prevent or treat cardiovascular disease and diabetes. Studies on rodents reveal that periodic fasting helps reduce fat and decrease insulin levels.
Intermittent fasting directly affects the complex gut microbiota in obese persons and helps gut microbes use more energy from the food. Some studies suggest that mice on fasting diets had longer lifespans, fewer tumors, and lower blood sugar.
One randomized clinical trial involving 71 persons on fasting diets resulted in lower body fat, blood pressure, and waist size.
Levels of a hormone promoting aging, IGF 1, also decreased considerably in rodents who were on a low-calorie diet. Rodents that were at higher risk for age-related illness also had lower blood sugar and cholesterol levels after receiving a diet that included intermittent fasting.