Does Intermittent Fasting Work for Weight Loss?

Intermittent fasting is an approach that encourages eating at set times within a day or week. Meals (and sometimes liquids) are not allowed outside these set times.

The exact eating-and-fasting schedule people follow when they are intermittently fasting may differ. The most common are 16:8 (eating during eight hours each day, fasting for the other 16) or 5:2 (eating normally [i.e., not a restricted caloric intake] five days a week, and eating only around 500 calories for the other two days).

This is because intermittent fasting is so adaptable (for example, a person could fast for 12 hours, then consume a meal for 12 hours, last for up to 14 hours, and that for 10). It’s a great idea to talk with an experienced dietitian about the excellent method of intermittent fasting that will suit our needs.

How Does Intermittent Fasting Affect Your Health?

There are a variety of methods to perform intermittent fasting. They all revolve around picking regular times of the day to take a meal and fast. 

For instance, you could only eat for 8 hours daily and fast for the rest. You could also opt only to eat one meal per day, two times every week. There are numerous different intermittent fasting routines.

Mattson states that after a long period of a non-nourishing diet, the body is able to exhaust its sugar stores and then begin burning fat. Mattson refers to this as metabolic switching.

Intermittent fasting contrasts with the normal eating pattern for most Americans, who eat throughout their waking hours. If someone is eating three meals a day, plus snacks, and they’re not exercising, then every time they eat, they’re running on those calories and not burning their fat stores.”

Intermittent fasting is a method of extending the time your body burns off the calories you ate during the last meal before beginning to burn calories again.

Is Intermittent Fasting A Reliable Method For Achieving Weight Loss?

The question remains a mystery due to the lack of evidence that usually involves extremely tiny sample sizes, short time intervals for intervention, diverse research designs (often with no control groups), and different fasting regimens and participants of various sizes and shapes. 

The research regarding intermittent fasting and its effects on weight loss mainly involves studies using the method of time-restricted eating used in intermittent fasting. Recent research suggests that restricting your eating time could help you lose some weight.

Choosing Your Intermittent Fasting Plan

There are a variety of intermittent fasting methods. The most popular options are:

• The 16:8 method
• 5:2 is the 5:2 diet
• the Warrior diet
• Eat Stop Eat
• alternate-day fasting (ADF)

The 16/8 Method

16/8 is an intermittent fasting plan. The 16/8 fasting intermittent program requires avoiding food for the remaining 16 hours and limiting food consumption and calorie-rich drinks to a specific timeframe of 8 hours each day.

This 16/8 method is flexible and based on a time-restricted consumption (TRE) concept. You can choose any time period of 8 hours to eat calories.

A few people have breakfast but eat between noon and 8pm, while others avoid eating later and adhere to an 8 a.m. until 5 p.m. timetable.

Research has shown that time-restricted eating habits like the 16/8 technique could prevent hypertension and decrease calories consumed, leading to weight loss.

A review of research conducted in 2023 revealed that the 16/8 technique and 16/8 in combination with limiting calories are effective strategies for weight loss in adults suffering from obesity or being overweight. 

Meal times that began prior to noon resulted in greater weight reduction than ones that started at noon. Researchers also observed that they could have positive effects on glucose metabolism.

A study in 2019 showed that the 16/8 technique did not affect gains in muscle strength of women doing resistance training.

The 5:2 Method

5:2 Diet is an easy intermittent fasting program.

Five days a week, you eat the way you would normally and don’t limit calories. On the two other days, you cut down on your calories to one-quarter of what you need for your daily requirements.

If you consume the equivalent of 2,000 calories a day, it is recommended that you reduce your consumption to 500 calories per day, twice a week.

According to a 2018 study, the 5:2 diet was as effective as daily calorie restrictions in reducing weight and blood glucose control in those with type 2 diabetes.

Another study showed that the 5:2 diet is equally efficient as continuous calorie restriction for weight loss and treating metabolic diseases such as diabetes and heart disease.

In the 5:2 lifestyle, you choose the days you do not fast. There is no set of rules for what you should consume on days that are high in calories. However, an appropriate, balanced diet and nutritious whole foods can aid in weight loss and overall well-being.

Eat Stop Eat

Eat Stop Eat is an alternative method of intermittent fasting, popularized by Brad Pilon, author of the book “Eat Stop Eat.”

The intermittent fasting program involves identifying two or three days in a week when you eat nothing for 24 hours.

On the other days of the week, you can take your time eating, but it’s recommended that you stick to a balanced diet and avoid excessive consumption.

The reason behind a weekly 24-hour fast is that eating fewer calories can lead to weight reduction.

Fasting for as long as 24 hours may trigger an alteration in metabolism that causes the body to turn to fat for energy rather than glucose.

More research is needed on this diet to discover its health and weight loss benefits.

Fasting On Alternate Days

Alternate-day fasting is an easy-to-remember method of intermittent fasting. With this plan, you will fast regularly daily, but you can stick to your usual eating habits during non-fasting days.

Some variations of this diet incorporate a “modified” fasting strategy that includes eating 500 calories on fasting days. Some versions also eliminate calories on fasting days.

Fasting for a few days on alternate days has shown weight loss advantages.

A previous randomized pilot study conducted in 2016 comparing intermittent fasting with the daily caloric limit in obese adults found both are equally efficient in weight loss.

Another study revealed that participants ate less calories by 37% while losing an average of 7.7 kg (3.5 kg) when alternating between 24-hour fasts and not eating for four weeks.

If you’re looking to lose weight, exercising and fasting on alternate days can benefit you and increase your heart health.

If you’re not used to intermittent fasting, begin by easing into the alternate-day fasting phase with the benefit of a modified plan for fasting.

The Warrior Diet

The Warrior Diet is an intermittent fasting regimen inspired by the eating patterns of warriors from the past.

The Warrior Diet was developed in 2001 by Ori Hofmekler. It is a bit more extreme than the 16-to-8 method but is not as restrictive as the Eat Stop Eat method.

It involves eating very little for 20 hours during the day and then consuming as much food as you like during a four-hour period in the evening.

The Warrior Diet encourages dieters to eat small portions of dairy-based products, hard-boiled eggs, raw vegetables and fruits, and non-calorie drinks during the 20-hour fast.

After this 20-hour fast, individuals can basically have any food they want for 4 hours; however, clean, nutritious, and organic food items are suggested.

Time-restricted feeding cycles can offer many health advantages. Research has shown that they may prevent cancer progression, reduce diabetes during aging, slow down aging, and boost the lifespan of rodents.

A study in 2020 found that fasting during a 4-hour feeding window was no advantage over fasting with a 6-hour feeding window.

Further research is required regarding the Warrior Diet to understand its advantages in weight loss.

The Warrior Diet may lead to disorders in eating patterns. It’s accurate to consult your doctor to determine if this eating plan is appropriate.

How Can Intermittent Fasting Affect Hormones?

Since intermittent fasting has become more commonplace, questions have surfaced because research conducted on rats has shown that it can affect the fertility cycle and hormonal balance. These fears have been amplified through social media.

“There have been a couple of animal studies that I don’t think are very translatable to humans,” Varady explained. “But everyone finds out about them the second they’re up on Instagram.”

A 2022 study in the Journal of Obesity looked into the effects of intermittent fasting on women’s hormone levels. Women in two groups complied with restricted eating regimens over eight weeks. The final results were positive.

Postmenopausal women’s levels of estradiol and progesterone did not change. The only hormone that changed significantly during the study period was dehydroepiandrosterone, also called DHEA.

The two groups of women participating in the study experienced a statistically significant drop in DHEA levels during the eight weeks following the strict time-restricted diet. 

However, Varady said that, even with the decline in levels, the subjects’ DHEA amounts were within normal levels—and they didn’t exhibit any significant side effects on other tests.

Intermittent Fasting Risks

Research into intermittent fasting has discovered that this method of eating could pose some risks in addition to its potential advantages. These could range from feeling ill during fasting to avoiding more serious dangers to one’s well-being.

Effects of intermittent fasting

In long periods, it can be dangerous. A few adverse effects linked to intermittent fasting have been studied. These include:

• Dizziness
• Nausea
• Insomnia
• Headache
• Weakness
• Changes in mood
• Urinary needing frequently

Certain studies have also revealed that people who are on intermittent fasting lose muscles. Doctors advise that people trying intermittent fasting tend to eat more when not fasting for a certain period.

If you’re getting older and overweight, losing too much weight could impact your bone health, immune system, and energy levels.

Is Intermittent Fasting A Safe Method?

Some people try intermittent fasting to manage weight, while others utilize this method to treat chronic ailments like IBS, high cholesterol, or arthritis. But intermittent fasting isn’t suitable for everyone.

Before you begin an experiment with intermittent fasting (or any other diet), make sure to consult your primary healthcare provider first. 

Specific individuals should avoid the idea of intermittent fasting:

• Teenagers and children under the age of 18.
• Women who are nursing or pregnant.
• People suffering from type I diabetes are taking insulin. Although an increasing number of clinical studies have proven it is safe to fast for people who have type 2 diabetes intermittently, there are no studies conducted on those who have type 1 diabetes. Mattson states, “Because those with type I diabetes take insulin, there is a concern that an intermittent fasting eating pattern may result in unsafe levels of hypoglycemia during the fasting period.”
• Patients who have an eating disorder history

However, those who do not fall into these categories but who are able to safely practice intermittent fasting can follow the practice for as long as they want. It could be a lifestyle change, and it can be beneficial.

Remember that intermittent fasting can result in different reactions for individuals. Consult your physician if you experience unusual headaches, anxiety, nausea, or other symptoms when you begin intermittent fasting.

Key Takeaway

IF should be something other than what people should do. It’s one of the many ways to raise one’s overall health. The most crucial elements to focus on are nutritious food choices, exercise regularly, and sufficient rest.

The bottom line is that a universally applicable nutrition solution needs to be available. It is essential to know that the accurate nutrition plan that you can follow for your needs is one that you will stick to over the long term.

If you’re feeling great when you fast and realize it can be a healthy method of eating, it could be an extremely effective tool to shed excess weight and boost your overall health.

FAQ

Can I lose weight by intermittent fasting?

A comprehensive review of 40 studies showed that intermittent fasting is effective in weight loss, with an average loss of 7-11 pounds in 10 weeks. The research was varied, ranging from 4 to 334 participants and 2 to 104 weeks in length.

Are you able to lose belly fat with intermittent fasting?

Optimal Intermittent Fasting Method For Subcutaneous Belly Fat

• 16/8 Method 16/8 Method: Fast for 16 hours, then consume 8 hours of food daily.
• 5:2 Method: Using the 5:2 method, you eat your usual diet five days per week. You consume 500-600 calories during the two days of fasting.

Why can’t I lose weight while fasting 16:8?

Why can’t I lose weight while fasting 16:8? If you’ve tried intermittent fasting and aren’t losing weight, the possible causes are excessive eating during your eating time and lousy eating habits. To help boost your diet, consider eating fewer calories, eating in a balanced way, or setting up a smaller or larger eating window.