Intermittent fasting is an eating pattern that focuses on when you should eat foods and when not to. It involves periods of eating and fasting rather than specifying the type of foods to eat. This way your body will get time to burn stored fat for energy during fasting periods. It is considered an effective way to lose weight and improve metabolism. One of the popular types of intermittent fasting is the 16/8 method, which means you have to fast for 16 hours and eat within an eight-hour window. While the 16/8 intermittent fasting plan can be effective, it can also have side effects.

What is 16/8 intermittent fasting?

The plan is a type of intermittent fasting where you fast for 16 hours each day and consume foods within an eight-hour window. “It is one of the most popular and manageable forms of fasting because much of the fasting period typically occurs overnight, during sleep,” says nutritionist Haripriya. N. For example, if you choose to eat between 12 pm and 8 pm, you will fast from 8 pm until 12 pm the next day. While you are fasting, you can consume water, tea, coffee or other beverages without calories. This method is often used for weight loss, and improved metabolic health, as it encourages the body to burn stored fat during the time of fasting.

Also Read: Intermittent fasting 101: Everything you need to know about this eating pattern

What are the benefits of 16/8 intermittent fasting?

Before you start this diet, you must know how it can benefit you:

1. Aids weight loss

During the 16-hour fasting period, the body depletes its glycogen stores (sugar from food) and begins burning stored fat for energy. “This leads to fat loss, particularly around the abdomen,” says the expert. The 16/8 intermittent fasting plan can be a therapeutic strategy for weight control in adults who are overweight and obese, as per research published in the Food Science & Nutrition journal in 2022.

2. May prevent type 2 diabetics

Intermittent fasting using the 16/8 method may help to prevent type 2 diabetes. Lifestyle modification with an intermittent fasting method like 16/8 may help lower blood glucose levels, and maintain body mass index, as per research published in the Diabetology journal in 2023. Fasting for 16 hours allows insulin levels to drop, which enhances insulin sensitivity. This means the body can regulate blood sugar levels more efficiently, reducing the risk of insulin resistance and type 2 diabetes.

3. Increases energy and mental clarity

When the body shifts to burning fat for energy, people tend to feel more alert and energised. “It may also help improve cognitive function, memory, and focus due to the brain’s efficiency in utilising fat as a fuel source,” says the expert. Improved mental clarity and energy levels are important, as they can enhance productivity and focus.

4. Controls cravings

Fasting can help reduce cravings for unhealthy, high-calorie foods. “When you restrict your eating window, you may become more mindful of what you eat, which often leads to healthier food choices,” says the expert. Over time, intermittent fasting can retrain your body to be satisfied with less food and regulate hunger hormones like ghrelin, which is the hunger hormone.

5. Preserves lean muscle mass

The 16/8 intermittent fasting plan may help preserve lean muscle mass while reducing fat mass. An intermittent fasting programme (16/8 method) along with resistance training could decrease fat mass, and maintain muscle mass, according to a 2016 study published in the Journal of Translational Medicine.

What are the rules of 16/8 intermittent fasting?

If you plan to follow the this fasting plan, remember these rules –

• You must fast for 16 hours straight. During this time, no food is consumed, but you can drink water or non-caloric beverages.
• Each day, you can eat your meals only during the chosen eight-hour window, which can be between 12 pm and 8 pm or 10 am to 6 pm, depending on what fits your schedule.
• Aside from water or non-caloric drinks, consuming anything with calories (even small snacks) breaks the fast.
• Though you have freedom in what you eat during the eight-hour window, it is important to focus on nutrient-dense foods, so eat vegetables, fruits, lean proteins, and whole grains.
• Since the goal is to create a calorie deficit for weight loss, overeating during the eight-hour window can negate the benefits of fasting.

What are the side effects of 16/8 intermittent fasting?

This fasting plan can provide numerous health benefits, but it may also come with side effects, especially in the first few days. Here are the most common side effects –

1. Hunger and cravings

During the fasting period, especially in the beginning, your body may crave food and feel hungry because it is adjusting to the new eating pattern. “This is particularly common for people used to eating frequently or snacking throughout the day,” says Haripriya.

2. Irritability or mood swings

Hunger can cause irritability, especially if your body is used to eating regularly. Blood sugar levels may fluctuate as your body adjusts, and contribute to mood changes. Drinking water, tea, or black coffee during fasting can help curb hunger. “Also, focusing on consuming complex carbohydrates, healthy fats, and proteins during your eating window can help stabilise blood sugar levels,” says the expert.

4. Digestive Issues

Changes in eating patterns, especially restricting eating to an eight-hour window, may disrupt digestion. Digestive issues like indigestion, diarrhea, and bloating are some of the side effects you may experience while doing intermittent fasting, according to research published in PLOS One in 2019.

5. Headaches

Headaches can occur during the fasting period. It is a possible side effect of any type of fasting, including intermittent fasting, as per research published in the Frontiers In Nutrition journal in 2020. It may happen due to dehydration, low blood sugar levels, or caffeine withdrawal that is if you are used to consuming caffeinated beverages with food.

6. Nutrient deficiencies

If not planned carefully, fasting may lead to inadequate intake of essential nutrients, particularly if your meals during the eating window are not balanced. Prioritise eating whole foods in your diet to ensure you are getting all the vitamins, minerals, and macronutrients like proteins, and carbohydrates needed by your body.

How long should you practice 16/8 intermittent fasting?

“When it comes to a this fasting plan, there is no strict time limit, but here are some factors to consider,” says Haripriya.

• If your primary goal is to lose weight, you can follow 16/8 intermittent fasting until you reach your desired weight. Many people follow this pattern for several weeks to a few months to achieve their weight loss targets.
• If you aim to improve metabolic health or insulin sensitivity, intermittent fasting may be beneficial for a period of 8 to 12 weeks or longer, depending on how your body responds.
• Some people adopt 16/8 intermittent fasting as a long-term eating pattern, not just for weight loss, but for overall health benefits like improved energy, mental clarity, and diabetes prevention. Since 16/8 is relatively flexible and manageable for most people, it can be maintained indefinitely as a part of a healthy lifestyle.
• Some people may prefer to take periodic breaks, especially during holidays or special events, and resume afterward. This helps prevent burnout or the feeling of restriction.

Also Read: Shed the extra kilos with this 7-day diet plan for weight loss

If you have any underlying health conditions, it is important to consult a doctor before continuing intermittent fasting long-term.

The 16/8 intermittent fasting plan can be an effective strategy for weight loss and boosting energy. But it can lead to digestive issues and nutrient deficiencies, so combine it with healthy eating and regular exercise.