In the world of medicine and nutrition, the search for effective strategies for weight management and improved metabolic health is continuous. Among the different alternatives that have emerged in recent decades, one approach has gained significant attention: the 5:2 diet or fasting mimicking diet.

In this article on our Salengei blog, we will discuss this diet based on principles of intermittent calorie restriction, which has been the subject of numerous scientific studies exploring its effects on weight loss, cardiovascular health, and metabolism. In addition, we will investigate in depth its physiological foundations and the scientific evidence that supports its effectiveness.

What are the fundamentals of the 5:2 diet?

Currently, a common approach to losing weight is daily energy restriction. This regimen limits daily energy intake and has been shown to be effective in achieving significant weight loss. However, long-term effectiveness is limited due to declining compliance over time. Intermittent fasting is a dietary regimen that currently receives attention, in part due to diets popularized by celebrities and celebrities and, although it has been used historically, particularly in religious settings, it has three main variations: time-restricted eating, alternate-day fasting, and the 5:2 method. In another article by Salengei we have already talked in depth about the generalities of intermittent fasting. You can click here to read it.

The 5:2 diet is based on a cycle of five days of normal eating followed by two days of partial fasting. During fasting days, caloric intake is limited to one-quarter or one-fifth of the usual intake, which is roughly equivalent to 500-600 calories for women and 600-700 calories for men. This intermittent eating pattern has become popular for its simplicity and flexibility, making it attractive to many people looking to lose weight, detoxify their body, and improve their health without following extreme long-term dietary restrictions.

Proponents of the 5:2 diet argue that intermittent fasting induces a number of beneficial physiological changes, including the activation of metabolic pathways related to fat burning and cell repair. These changes can lead to sustained weight loss, improvements in blood glucose levels, and a reduced risk of chronic diseases such as type 2 diabetes and cardiovascular disease.

Inquiring about the scientific evidence

Effects on decreasing fat content in the liver.

To evaluate the effects of a 5:2 fasting diet on liver fat content, a prospective, randomized 24-week study was conducted in patients presenting with non-alcoholic fatty liver disease and type II diabetes. Sixty-one patients were enrolled for the study and randomly divided into a 5:2 fasting diet intervention group and a 1.8 mg/day liraglutide intervention group. During the study, data were collected on body weight, waist circumference, plasma lipids and glucose profile, fasting plasma insulin and liver function parameters. The controlled attenuation parameter was measured to assess liver fat content. Superoxide dismutase (SOD) and malondialdehyde were measured to assess oxidative stress status.

At the conclusion of the intervention, the controlled attenuation parameter of PDA decreased significantly in both the 5:2 diet group and the liraglutide group, compared to baseline. Body weight, plasma lipid and glucose profile, and liver function parameters improved significantly, while the homeostasis-β model (HOMA-β) assessment increased significantly in both groups. Linear step regression showed that increased HOMA-β and SOD, as well as reduced body mass index (BMI), were the independent predictors of decreased PDA in the group taking liraglutide. In contrast, the reduction in BMI and MDA were the independent factors influencing the decrease in PDA in the 5:2 diet group. Common side effects in the 5:2 diet group were hunger (60%), weakness (10%), and constipation (0.3%).

In conclusion, it was seen that a 5:2 fasting diet achieved comparable effects with liraglutide on liver fat content in patients with type II diabetes and non-alcoholic fatty liver, by reducing BMI and oxidative stress. Both treatment strategies were safe and effective for glucose control. https://doi.org/10.1089/met.2022.0014

Effects on weight loss

One study aimed primarily to compare the effects of weight loss from three groups over 12 weeks of weight loss. The primary outcome measure was change in percentage of total weight loss. The secondary outcome measures were the ratio of fat mass, total mass and the ratio of fat-free mass to total mass.

Thus, it was shown that the 5:2 intermittent fasting program produced superior weight loss compared to daily calorie restriction in Chinese patients who were overweight or obese. Still, a longer-term prospective randomized controlled trial is needed. https://doi.org/10.3390/nu14224734

Effects on aging

To assess tolerance of the 5:2 diet and explore the effects on biological mechanisms related to aging and metabolism, one study recruited a cohort of 24 healthy individuals in a randomized, double-blind, crossover clinical trial. Study participants underwent two 3-week treatment periods: intermittent fasting and intermittent fasting with antioxidant supplements (vitamins C and E). Participants found the diet tolerable, with no adverse clinical findings or weight changes. Even so, a marginal increase (2.7%) in SIRT3 expression due to diet was detected, but no changes in the expression of other genes or markers of oxidative stress were analyzed. Intermittent fasting was also found to decrease plasma insulin levels (1.01 μU/mL). https://doi.org/10.1089/rej.2014.1624

Benefits studied

According to information we’ve been able to gather from Dr. Valter Longo, who is a renowned biogerontologist at the University of Southern California, several of his studies have shown that intermittent fasting induces beneficial cellular and molecular responses, including:

• Autophagy: or cellular cleansing essential for the elimination of damaged proteins and dysfunctional organelles, promoting cell renewal.
• Insulin regulation: improves sensitivity and reduces insulin resistance, a key factor in the development of type 2 diabetes.
• Reduced oxidative stress: increased production of antioxidant enzymes that fight free radicals, protecting cells from damage and preventing chronic diseases.
• Decreased inflammation: modulation of inflammatory pathways, reducing the levels of pro-inflammatory markers associated with various diseases.
• SIRT pathway activation: Activation of sirtuin 3 (SIRT3), a protein with anti-aging effects and cardiovascular and metabolic health benefits.

Conclusions

With the emergence of social media, we have witnessed an unprecedented increase in the dissemination of information. This has been further increased since the almost sudden emergence of content-generating artificial intelligence. Added to this is the disclosure made by celebrities who express and share their own experiences without measuring the impact they will have on their followers.

Although intermittent fasting is a dietary intervention with proven benefits, one of its main disadvantages is its continuity over time.

Among the recognized and studied benefits are significant weight loss, mainly at the expense of body fat, while preserving muscle mass. It also improves the lipid profile with a reduction in LDL cholesterol and an increase in HDL, improving cardiovascular health.

On the other hand, glycemic regulation has been seen by improving insulin sensitivity and reducing blood glucose levels and a decrease in inflammation with reduced levels of inflammatory markers such as interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-α), associated with various chronic diseases.

In summary, the 5:2 diet is a promising dietary intervention with significant potential to improve health and well-being. Current scientific research is favorable, but more studies are needed to confirm its long-term benefits and better understand its mechanisms of action.