How many calories to eat during intermittent fasting 18/6?

How many calories to eat during intermittent fasting 18/6?


Intermittent fasting has gained popularity in recent years as a dietary approach that can aid weight loss and improve overall health. One of the most common fasting protocols is the 18/6 method, where individuals fast for 18 hours and have a restricted eating window of 6 hours. However, a common question that arises is how many calories should be consumed during this eating window. In this article, we will explore the optimal calorie intake during intermittent fasting 18/6 and its potential benefits.

Calorie Intake During Intermittent Fasting 18/6

When following the 18/6 intermittent fasting protocol, it is essential to maintain a balanced and nutritious diet within the restricted eating window. The calorie intake during this period will depend on various factors such as age, gender, activity level, and weight goals. However, it is generally recommended to consume the same number of calories as one would on a regular diet, but within the shorter eating window.

Calorie Deficit for Weight Loss: If the goal of intermittent fasting is weight loss, it is crucial to create a calorie deficit. This means consuming fewer calories than the body needs to maintain its current weight. A general rule of thumb is to aim for a calorie deficit of 500-1000 calories per day, which can result in a healthy and sustainable weight loss of 1-2 pounds per week. However, it is essential to consult with a healthcare professional or registered dietitian to determine the appropriate calorie deficit based on individual needs and goals.

Calorie Maintenance for Weight Maintenance: For individuals who are already at a healthy weight and want to maintain it, consuming the same number of calories as the body requires for weight maintenance is recommended. This ensures that the body receives adequate nutrition and energy without leading to weight gain or loss. Calculating the exact calorie maintenance level can be done using online calculators or consulting with a healthcare professional.

Calorie Surplus for Weight Gain: Some individuals may have the goal of gaining weight or building muscle while following intermittent fasting. In such cases, a calorie surplus is necessary. This means consuming more calories than the body needs for weight maintenance. It is generally recommended to aim for a surplus of 250-500 calories per day to support muscle growth and weight gain. Again, it is advisable to seek guidance from a healthcare professional or registered dietitian to determine the appropriate calorie surplus based on individual needs.

Potential Benefits of Intermittent Fasting 18/6

Aside from calorie intake, intermittent fasting 18/6 offers several potential benefits for overall health and well-being. Some of these benefits include:

Weight Loss: Intermittent fasting can help promote weight loss by reducing overall calorie intake and increasing fat burning. By restricting the eating window to 6 hours, individuals are more likely to consume fewer calories throughout the day, leading to a calorie deficit and subsequent weight loss.

Blood Sugar Control: Intermittent fasting has been shown to improve insulin sensitivity and blood sugar control. This can be particularly beneficial for individuals with prediabetes or type 2 diabetes.

Improved Brain Function: Some studies suggest that intermittent fasting may enhance brain function and protect against neurodegenerative diseases. It may also promote the growth of new nerve cells and improve cognitive function.

Inflammation Reduction: Chronic inflammation is associated with various health conditions, including heart disease, diabetes, and certain cancers. Intermittent fasting has been shown to reduce inflammation markers in the body, potentially lowering the risk of these diseases.


When following the intermittent fasting 18/6 protocol, the calorie intake during the eating window should align with individual goals such as weight loss, weight maintenance, or weight gain. It is important to create a calorie deficit, maintenance, or surplus based on these goals and consult with a healthcare professional or registered dietitian for personalized guidance. Intermittent fasting 18/6 offers various potential benefits, including weight loss, blood sugar control, improved brain function, and reduced inflammation.


1. Mayo Clinic:
2. National Institute on Aging:
3. Harvard Health Publishing:
4. American Heart Association: