The concept of intermittent fasting has taken the health and wellness world by storm.

Early research suggests that engaging in periodic, short-term fasting practices could be a simple but effective way to shed unwanted weight and improve metabolic health.

There are multiple ways to implement an intermittent fasting protocol into your routine, but one method that’s becoming increasingly popular is known as Eat Stop Eat.

This article reviews everything you need to know about the Eat Stop Eat diet, including how to implement it, whether it’s effective for weight loss, and possible drawbacks to consider before diving in.

Eat Stop Eat is a unique approach to intermittent fasting that’s characterized by the inclusion of up to two non-consecutive fasting days per week.

It was developed by Brad Pilon, author of the popular and aptly titled book “Eat Stop Eat.”

Pilon was inspired to write this book after researching the effects of short-term fasting on metabolic health at the University of Guelph in Ontario, Canada (1).

According to Pilon, the Eat Stop Eat method isn’t your typical weight loss diet. Instead, it’s a way to reevaluate what you have been previously taught about meal timing and frequency and how that relates to your health (1).

How it’s done

Implementing the Eat Stop Eat diet is relatively straightforward.

You simply choose one or two non-consecutive days per week during which you abstain from eating — or fast — for a full 24-hour period.

For the remaining 5–6 days of the week you can eat freely, but it’s recommended that you make sensible food choices and avoid consuming more than your body needs.

Though it seems counterintuitive, you will still eat something on each calendar day of the week when using the Eat Stop Eat method.

For instance, if you’re fasting from 9 a.m. Tuesday until 9 a.m. Wednesday, you’ll make sure to eat a meal prior to 9 a.m. on Tuesday. Your next meal will occur after 9 a.m. on Wednesday. This way, you ensure you’re fasting for a full 24 hours — but not longer.

Keep in mind that even on fasting days of Eat Stop Eat, proper hydration is strongly encouraged.

Drinking plenty of water is the best choice, but you’re also allowed other types of calorie-free beverages, such as unsweetened or artificially sweetened coffee or tea.

summary

Eat Stop Eat is a type of intermittent fasting diet in which you fast for 24 hours once or twice per week.

One of the main reasons people are implementing intermittent fasting diets like Eat Stop Eat is to encourage weight loss.

Though there are currently no studies specifically evaluating Eat Stop Eat for weight loss, mounting evidence suggests that the periodic, prolonged fasting that Eat Stop Eat employs may support weight loss efforts for some people (2).

Calorie deficit

The first — and perhaps most obvious — way that Eat Stop Eat may promote weight loss is through a calorie deficit.

It’s well understood that losing weight requires you to consume fewer calories than you burn (3).

When applied properly, Eat Stop Eat sets you up for 1–2 days’ worth of a calorie deficit each week. Over time, this reduction in your total calorie intake could result in weight loss as you burn more calories than you take in.

However, current evidence doesn’t indicate that restricting calories for an entire day at a time is any more effective for reducing weight than the continual daily calorie restriction that most traditional diets utilize (2).

Metabolic shifts

Another way Eat Stop Eat could lead to weight loss is because of certain metabolic shifts that occur when your body is in a fasted state.

The body’s preferred fuel source is carbs. When you eat carbs, they’re broken down into a usable form of energy known as glucose.

After roughly 12–36 hours of fasting, most people will burn through the glucose they have stored in their bodies and subsequently transition to using fat as an energy source instead. This is a metabolic state known as ketosis (4).

Early research suggests that because of this metabolic shift, prolonged fasting may favor fat utilization in a way that traditional dieting strategies can’t (4).

Still, data on this potential benefit is limited, and there seems to be significant variability in how quickly people transition into ketosis.

Thus, it’s unlikely that everyone will reach ketosis within the 24-hour fasting window used in the Eat Stop Eat diet.

More research is needed to better understand how metabolic changes that may occur on an Eat Stop Eat diet can influence fat reduction and overall weight loss efforts.

summary

Eat Stop Eat may support weight loss through calorie reduction and changes in metabolism. However, results cannot be guaranteed for everyone.

The fasting practices implemented in Eat Stop Eat are likely safe for most healthy adults. Yet, you should consider potential downsides if you’re thinking of trying it out.

Insufficient nutrient intake

Certain people may have a difficult time meeting all of their nutrition needs on the Eat Stop Eat diet.

When it comes to dieting, it’s not uncommon for people to think of food in terms of calories alone. But food is much more than calories. It’s also an important source of vitamins, minerals, and other beneficial compounds that support your most vital bodily functions.

It’s essential for anyone following Eat Stop Eat to pay close attention to the foods they eat on their non-fasting days to ensure adequate protein, fiber, vitamin, and mineral intake throughout their diet.

If you have particularly high nutritional demands or currently struggle to eat enough food to meet your needs, removing 1–2 days’ worth of food could contribute to insufficient nutrient intake or unhealthy weight loss.

Low blood sugar

Some people use intermittent fasting diets like Eat Stop Eat to improve blood sugar control and insulin sensitivity (5).

Most healthy people have no difficulty maintaining blood sugar levels during the 24-hour fasting periods required on Eat Stop Eat, but that may not be the case for everyone.

For some people, such as those with diabetes, extended periods without food may contribute to dangerous blood sugar drops that could be life-threatening.

If you take blood sugar medications or have any medical conditions that cause poor blood sugar regulation, consult your healthcare provider before attempting Eat Stop Eat or any other diet than includes fasting (5).

Hormonal changes

Fasting practices implemented on the Eat Stop Eat diet may contribute to changes in metabolic and reproductive hormone production.

However, the specific health outcomes resulting from such hormonal changes are difficult to predict due to a lack of human research.

Some studies suggest that certain hormonal shifts may offer positive health benefits, such as improved fertility, while others indicate a potential risk for negative effects like inadequate reproductive hormone production and pregnancy complications (6, 7, 8, 9).

Because of the mixed data and limited total evidence, Eat Stop Eat is not generally recommended for anyone who’s pregnant, breastfeeding, or trying to conceive.

If you have a history of hormonal dysregulation, irregular periods, or amenorrhea, consult your healthcare provider prior to starting an Eat Stop Eat diet.

Psychological impact of restrictive eating

While many people report feeling more dietary freedom when using fasting as a weight loss aid, the restrictive nature of such eating patterns could have a negative psychological impact.

Some research indicates that short-term fasting may lead to irritability, volatile moods, and reduced libido (10).

That said, proponents of intermittent fasting often say that mood issues resolve after you have become accustomed to your fasting routine — though these claims haven’t yet been proven.

Restrictive dieting may also contribute to disordered eating behaviors, such as bingeing or obsessive thoughts about food and weight (11).

Because of this, Eat Stop Eat is not recommended for anyone with a history of disordered eating or a tendency toward developing these behaviors.

summary

Though fasting is safe for most healthy people, it may contribute to low blood sugar, insufficient nutrient intake, hormone shifts, and negative psychological effects.

At this point, there’s insufficient evidence to determine whether Eat Stop Eat is an effective weight loss method for everyone.

Studies have found various intermittent fasting strategies to be effective for achieving weight loss of up to 10% (2).

However, there’s immense variability in study designs, specific fasting protocols, and total weight loss, making it difficult to predict exact results for Eat Stop Eat (2).

Weight loss is a complex process that can be very unique to each individual. Many factors beyond calorie intake and meal timing affect your ability to lose or gain weight (12).

Ultimately, more long-term research on Eat Stop Eat is needed to determine whether it’s any more effective than other approaches to weight loss.

summary

Although early research suggests Eat Stop Eat may support weight loss, there’s currently not enough evidence to determine whether it’s an effective strategy for everyone.

Eat Stop Eat is a popular form of intermittent fasting in which you fast for 24 hours once or twice per week.

Research on this particular eating pattern is limited, but it may support weight loss by way of reduced calorie intake and changes in metabolic function that favor fat loss.

However, no specific results can be guaranteed.

Though fasting is generally considered safe, it could have negative side effects, such as inadequate nutrient intake, low blood sugar, and the development of disordered eating patterns.

As always, consult your healthcare provider if you’re unsure whether Eat Stop Eat is an appropriate weight loss strategy for you.