A recent opinion published in Clinical Nutrition ESPEN We provide a very detailed review of intermittent fasting and the ketogenic diet, and strategies for combining these approaches to manage chronic health conditions.
study: Intermittent fasting with a ketogenic diet: a combined approach for the management of chronic disease. Image Credit: EZ-Stock Studio/Shutterstock
What is intermittent fasting?
Intermittent fasting is a time or food restricted eating pattern where food and drink are allowed for a defined period of time followed by fasting.
Timed fasting allows you to have meals and snacks one to three times a day, depending on your timed eating pattern. The fasting period is 12 to 23 hours a day. With regular fasting, the duration of the fast can range from 2 days to 21 days or longer.
Timed fasting is used to gradually reduce calorie intake over time. This approach suggests that small morning and early afternoon mealtimes are superior to late afternoon or evening mealtimes in reducing fat accumulation, insulin resistance, and inflammation. I’m here.
Previous research has shown that time-limited fasting can help with weight management and muscle mass improvement. Additionally, prolonged, time-limited fasting has been shown to improve metabolism and protect against cardiovascular and metabolic diseases.
Dietary fasting focuses on the types and amounts of food that can be consumed during the fasting period. There are different types of food-restricted fasts, such as water-only, drink-only, and calorie-restricted fasts. However, in pure fasting, food and drink are completely prohibited.
Diet-restricted fasting can be used in conjunction with any type of diet plan, including vegan, vegetarian, paleo, ketogenic, or gluten-free diets. It has been shown to be safe and effective in
Both time restrictions and diet restrictions are equally effective in weight management. A combination of both approaches is also effective in managing chronic disease.
What are the stages of intermittent fasting?
Intermittent fasting can be divided into four stages: feeding, postabsorption and early fasting, fasting, and long-term fasting.
During the feeding phase, which begins shortly after eating, glucose acts as a trace fuel and insulin acts as a regulatory hormone, metabolizing glucose and inhibiting lipolysis. Excess glucose is stored in adipose tissue.
During the early stages of postabsorption and fasting, insulin levels fall, after which glycogenolysis is initiated to provide glucose. Lipolysis can also start at this stage.
During the fasting phase, glucose still serves as the primary energy fuel. However, a shift in fuel source from glucose to fatty acids begins. This can lead to flu-like symptoms, commonly known as “ketoflu.”
During the prolonged fasting phase, a complete metabolic switch occurs in which fatty acids become the primary energy fuel. In addition, BCAA catabolism is inhibited at this stage, leading to protein sparing and lower insulin levels.
In intermittent fasting, the fasting period should not exceed 12 hours initially. However, the duration can be gradually increased to achieve a complete metabolic switch to fatty acids. This is called the maintenance phase and can continue for long periods of time, from weeks to months.
What is a ketogenic diet?
A classic ketogenic diet refers to a high-calorie diet in which fat, carbohydrates, and protein constitute 70%, 10%, and 20% of your daily caloric intake, respectively. Dietary fats include natural fats and unprocessed monounsaturated and polyunsaturated fats from a variety of dietary sources. Saturated fats from animal products can also be used. Because they are rapidly metabolized, they raise high-density lipoprotein (HDL) cholesterol levels in the blood.
Modified ketogenic diets, such as the modified Atkins diet (MAD) and the low glycemic index diet, were developed in the 2000s to reduce fat consumption and increase carbohydrate consumption.
In healthy individuals, a combined intermittent fasting and ketogenic diet approach can be applied without specific monitoring. However, patients with chronic diseases should be monitored for tolerability and possible complications. . More specifically, it is important to continuously monitor body weight and blood levels of glucose, ketones, hemoglobin, lipid parameters, and inflammatory markers.
Combining intermittent fasting with a ketogenic diet
Both intermittent fasting and ketogenic diets induce a metabolic switch from glucose to fatty acids. Sirtuins, NAD+-dependent lysine-specific deacetylases, play important roles in the regulation of glucose and fat metabolism. Intermittent fasting has been shown to induce sirtuin expression.
A combination of intermittent fasting and a ketogenic diet can be applied to manage a variety of chronic diseases. Both strategies are effective in controlling intracranial pressure in conditions of traumatic brain injury, ischemic stroke, and status epilepticus, as well as protecting against cerebral ischemia and hypoxia.
This type of combination therapy may help manage a variety of diseases due to metabolic remodeling, such as diabetes, cardiovascular disease, and autoimmune diseases. The successful application of this combined approach depends on various factors, including patient-related and dietary factors.
Prior to implementing a combination of intermittent fasting and a ketogenic diet, the patient’s medical and family history of disease, as well as social history of alcoholism and substance abuse, should be carefully analyzed.
Professional discussion with patients about the health benefits of intermittent fasting and the ketogenic diet is essential for patient motivation. effective for
Patients should be given adequate time to adapt to changes in their diet. Once the desired outcome is achieved, the patient should be rewarded to support continued motivation.
With respect to dietary factors, it is important to accurately calculate calorie requirements and then develop an appropriate dietary plan prior to administration of the combination therapy. A proper ratio of macronutrients such as carbohydrates, proteins and fats should be maintained in the diet.
Dietary monotony can be avoided by choosing food from a variety of sources and recipes. Low glycemic index foods and vegetables are recommended.
Adequate hydration is also very important. Patients considering water-only fasting should consume 2-3 liters of water daily.
Combination therapy may not be suitable for children, pregnant or breastfeeding women. Additionally, patients with active infections, eating disorders, diabetic ketoacidosis, and acute or chronic pancreatic or liver disorders should avoid intermittent fasting combined with a ketogenic diet.
- Arora, N., Pulimamidi, S., Yadav, H., and others. (2023). Intermittent fasting with a ketogenic diet: a combined approach for the management of chronic disease. Clinical Nutrition ESPEN. doi:10.1016/j.clnesp.2023.01.024.