Cutting calories can suck. You are strategically starving yourself in order to lose weight.
Your body does not like this and will actively look for any opportunity to spare some calories.
By shedding muscle, changes in hormones, and impacting your energy to move around, your body is smart and activity tries to protect you from starving to death.
This is commonly referred to as a broken metabolism or as researchers call it metabolic adaptations. You can also think of this as a weight-loss plateau.
Research looking at diet breaks is showing some promising findings.
In this blog post, we will review the research and look at the importance and what you can expect when you take one!
What is a diet break?
A diet break is a period of time when you specifically avoid eating below a certain calorie threshold. This threshold is typically your maintenance level of calories. A diet break will normally follow a 2 to 12-week calorie deficit or weight loss phase. (1)
A diet break is typically longer than a cheat meal, cheat day, or refeed day.
For example, if you were dieting and consuming 1900 calories, 500 calories less than your maintenance calories (2400). The goal of a diet break, in this case, is to eat 2400 calories per day.
The goal of a diet break is to prevent or curb some of the metabolic, physical and, hormonal responses to a calorie deficit also referred to as metabolic adaptation. (2)
What is Metabolic adaptation?
Metabolic adaptation is the result of your metabolism, hormones, and behavior compensating for not getting enough energy. Ph.D. Layne Norton (Video above) is one of the researchers responsible for popularizing metabolic adaptation.
The exact mechanism is still under investigation, but from our understanding, metabolic adaptation is a decrease in your Total Energy Expenditure (TEE) and more specifically Resting Metabolic Rate (RMR).
Total Energy Expenditure is the number of calories that you use in a day. According to the FDA, the number of calories you need per day depends on age, gender, and activity level.
Female Calorie Chart
Male Calorie Chart:
Your RMR is the number of calories you burn at rest and it makes up 60-80% of your daily calorie expenditure.
A decrease in your RMR can be from a loss in muscle mass, changes in hormones (leptin, ghrelin, thyroid), and changes in how active you are. (3)
These adaptations were very useful in the past when food was not available these traits kept us from starving to death. However, in today’s modern world, where food is not scarce, it seems to not work in our favor.
How long is too long to diet?
Simply put, it depends. There are several factors that are going to affect the length at which you can successfully diet. (Actually see the results!) Some of these include factors include, muscle mass, gender, genetics, and body fat %.
In a study, a study looking at predicting metabolic adaptation using mathematical equations, research Kevin Hall stated, “the model simulations addressed the relative role of diet adherence vs. metabolic adaptation in explaining the typically observed weight loss plateau after ~6 mo of lifestyle modification.” (4)
This mathematical model was designed to look at why people experience a weight loss plateau at 6 months.
Even when we look at 2-year follow-ups on bariatric surgery participants you can see that (graph below) they ended up stalling out on their weight loss as well. (5)
With the greatest % of fat loss in the first 6 months followed by a small but significant amount of weight loss in the following 6 months. After that first year, no additional weight loss.
6 months is a long time to diet, and anything after that 6 month period, despite your efforts, you are going to start seeing a weight loss plateau.
This is where a diet break can come in handy!
Why do you need a diet break?
Dieting can be tough. You deprive yourself of your favorite foods, you’re always feeling hungry, and you’re constantly obsessing over food.
There’s research to support this, In 1944, 36 men participated in a study called the Minnesota Starvation Experiment that required them to lose 25% of their body weight.
The men were first examined for three months, eating around 3200 calories. They then were required to eat a semistarvation diet of 1570 calories for 6 months.
The men’s lifestyle included walking 22 miles per week and working 15 hours per day.
Researchers found that the men’s strength and energy decreased, as did their body temperature, heart rate, and sex drive.
The psychological effects were the most interesting part of the study. The men experienced an obsession with food.
They would dream about food, fantasize about food, and in fact, 3 men did not complete the study because their hunger was too difficult to manage.
The Minnesota Starvation Experiment is a great example of why you need a diet break.
The men in the study were not only physically hungry, but they were also mentally and emotionally exhausted.
Dieting can take a toll on your body and your mind and a break from dieting will become inevitable.
Signs you need a diet break
Dieting can be difficult. It requires a lot of willpower and self-control, and sometimes it can feel like you’re depriving yourself of the things you love most. If you’re thinking about taking a diet break, there are a few signs that may indicate it’s the right decision for you.
Fatigue: In a two-day double-blind placebo study of calorie restriction participants experienced a decline in, cognitive performance, aerobic exercise, mood, and self-reported exertion. (7)
Sleep disruptions: In a study looking at eating disorders and their effect on sleep, it was found that participants with anorexia nervosa and bulimia nervosa had more difficulty falling asleep and staying asleep than those without an eating disorder. (8)
Loss of menstrual cycle: According to OSHA the Office on women’s health, a regular menstrual is an indicator of good health and irregular periods are a sign of many issues but one is too much weight loss in a short period of time. (9)
Extreme Hunger: As seen in the Minnesota Starvation Experiment a calorie deficit can have a huge impact on your psychology and hunger. This is thought to be caused to do a shift in hormones. (6)
Experiencing any of these “signs” may be an indicator that you are adapting to the low amount of calories.
Diet break benefits
The benefits of implementing diet breaks are tangled up between attenuating the side effects of weight loss (calorie restriction) and having the same positive benefits as weight loss.
When compared, to a constant calorie deficit vs a calorie deficit that is broken up with a diet break, it would appear that the diet break has at least the same benefits if not having a few more.
This study had two groups, a continuous calorie-restricted group, and an intermittent calorie-restricted group. (2)
The continuous calorie-restricted group had a 33% reduction in calories for 16 weeks straight, with no breaks.
The intermittent calorie-restricted group also had a 33% reduction in calories however every 2 weeks they would have a 2-week break where they ate at a maintenance level of calories.
There was the same length of time, 16 weeks, spent in a calorie deficit between both groups.
The result was that both groups lost weight but the intermittent calorie restriction group showed additional benefits:
Greater weight loss: The group that had 2-week diet breaks experienced greater weight loss.
Preservation of muscle mass: Although the diet break group had greater weight loss, they also had less muscle loss.
While this is a new area of research and diet breaks need more well-controlled studies looking at the impact of diet breaks, the MATADOR study is a great start that shows there are benefits to taking a diet break.
How to take a diet break
There are many ways that you can incorporate diet breaks into your weight loss strategy. The most important thing is to find what works for you and your body.
The number one thing you should take into account is how much weight you want to lose. This is going to determine the length of time it would take to lose said weight.
With this information, you will be able to identify where a break might be needed.
For example, if you have 50 pounds to lose that can take 6 months or more of dieting to lose. It might be a good idea to break that up into two 3 month fat loss phases.
The next thing you should consider is the length and frequency of your diet break.
Think about diet breaks as taking one step back to take two steps forward, while they have been shown to improve weight loss, they are intentional breaks from calorie restriction.
You will not be actively losing weight during a diet break, in fact, you might see the scale go up.
However, by doing a diet break the time you spend in a calorie deficit phase will be more effective and you will lose more weight in the long run.
The third thing to look at is how you feel. Take inventory of your current situation.
– Are you low on energy?
– Have you been in a calorie deficit for more than a few months?
– Are you obsessed with food?
– Has your weight loss progress stalled?
– Are you struggling to fall asleep and stay asleep?
How long should a diet break be
A diet break can last anywhere from a few days to a couple of weeks. The length of your diet break should be based on how well you are coping with the calorie restriction and how much weight you have left to lose.
What happens after a diet break?
Taking a break from your diet and then getting back on track with your weight loss plan does seem to cause some initial weight gain.
This is normal and to be expected as your body starts to adjust back to a calorie deficit. The weight gain is usually water weight and glycogen (stored carbs).
You might see the scale go up by a few pounds but this is not true fat gain and will come off quickly once you start dieting again.
You might be worried that you will lose all the progress you made while dieting but this is not the case.
Diet Break Weight Gain
When you diet by restricting calories typically you are consuming fewer carbohydrates and fats. Carbohydrates are specifically stored in the muscle and liver as glycogen. Contributing to fluctuations in weight.
This glycogen storage is designed to be used up really quickly by the muscles during high-intensity training. However, when you are then restricting calories and not replenishing this storage you will weigh less.
To picture this I want you to think about your car, to run it needs gas, oil, a battery, and windshield wiper fluid. I don’t know I am not a mechanic but roll with me.
With all this stuff the car runs great, starts up every time, and can drive for miles. but it weighs more than it would without all this extra stuff.
When you have gained weight during a diet break think of this weight at you topping off all the things needed to make your car run. Sure you weigh more but you also have a full tank of gas.
Diet break Weight loss
The weight loss that occurs after a diet break is a result of your body no longer being in a calorie deficit and returning to maintenance calories.
The short periods of eating your maintenance level of calories will help prevent muscle loss, feed the hunger hormones, and maintains your resting energy expenditure all of which aid in future weight loss attempts.
frequently Asked Questions
How long should a diet break last?
To see the benefits of a diet break, it should last at least a few consecutive days. According to a study called Effectiveness of Diet Refeeds and Diet Breaks a Pre-contest Strategy stated,
“A diet strategy where a continuous string of 4+days to several weeks of weight maintenance calories (or slightly above) are consumed as part of the fat loss plan with a speciﬁc target of calories and macro/micronutrients for each day.” (1)
Will I gain weight on a diet break?
In the short term yes, by implementing a diet break you will strategically increase your calories (most in the form of carbohydrates) which will increase your glycogen stores, cause an increase in water weight, and lead to a slight increase on the scale.
In the long term, you will probably see an overall weight loss. Because you implemented a diet break, you would have helped maintain muscle, and energy burn throughout the day which will carry over to your fat loss phase.
Do diet breaks reset metabolism?
Your metabolism is based on several factors and adapts to getting enough or getting too little food. Diet breaks help prevent the adaptations to weight loss however there is no way to “reset your metabolism.”
You can increase your metabolism by increasing your lean body tissue and moving your body more while eating enough food. Or you can lower your metabolism by lowering the amount of muscle you have moving less and eating less.
Diet breaks are a great way to make a weight loss journey suck less. They are a way of strategically eating more calories to lose weight and help prevent weight loss stalls.
Although the research is relatively new this approach has had some promising findings.
In this blog post, we dug through the research, and discussed the importance of diet breaks and what you can expect when you take one!
I hoped this answered all your questions about diet breaks.
Thanks for reading!
Do you have any questions about diet breaks? Maybe you have hit a weight loss plateau, apply for one on one coaching today.
Remember: this post is for informational purposes only and may not be the best fit for you and your personal situation. It shall not be construed as medical advice. The information and education provided here is not intended or implied to supplement or replace professional medical treatment, advice, and/or diagnosis. Always check with your own physician or medical professional before trying or implementing any information read here.
Noah Quezada is a Registered Dietitian Nutritionist located in Denver, Colorado. Over the course of more than a decade, he has gained extensive experience in helping clients manage their weight through in-person sessions. Noah is also the 2023 President of the Colorado Academy of Nutrition and Dietetics.