Have you been dieting for as long as you can remember? Are you following a very low-calorie diet? Are you struggling to break through a fat loss plateau?
If you answered yes to any of these, you might need a refeed day.
If you’ve ever tried to lose weight, you might have experienced the seemingly inevitable plateau or even rebound that happens after weeks or months of dieting.
Week after week, your weight loss might seem to get slower and slower, until finally the number on the scale stops moving at all.
Intuition and science both tell us that we need to continue to cut calories to jumpstart progress.
But science also tells us something else that we can use to “cheat” the system: your body adjusts to decreased energy intake when dieting.
Why Does Weight Loss Stall?
When we diet, leptin levels are low, triiodothyronine (T3) and thyroxine (T4) levels are low, and cortisol levels are high. Leptin inhibits hunger, T3 and T4 increase basal metabolic rate (BMR), and cortisol increases blood sugar and accelerates protein breakdown.
The human body has evolved to hold onto body fat, even at the expense of losing lean mass. The trick is to reverse or stunt these negative adjustments by making your body think that it’s not dieting anymore.
What Is a Refeed Day?
A “refeed day” is a specific type of carbohydrate cycling strategy. Instead of having high carbohydrate days, medium carbohydrate days, and low carbohydrate days, you have “normal” carbohydrate days and high carbohydrate days (i.e. refeed days).
Increasing carbohydrate intake can increase leptin levels and energy expenditure1,2. A carbohydrate refeed will also boost insulin levels, which is beneficial, since insulin inhibits muscle protein breakdown5 and can stimulate testosterone production, at least in men6.
Refeed days can be especially important for females, as menstruation can cease when leptin levels are low enough7, potentially contributing to long-term health issues.
The frequency of refeed days and the percent increase in carbohydrates necessary on refeed days depend on numerous factors including: length of diet, how severe the calorie deficit is, carbohydrate intake, body fat level, physical activity level, and genetics. Generally, the more you normally restrict your carbohydrate intake, the more carbohydrates you will need to consume for a refeed.
This effect has not been seen with an increase in fat intake2, and in fact, increasing dietary fat intake on a refeed day might interfere with the increase in leptin levels3, 4.
Refeed days can help ease the terrible struggles of dieting. Staying in a caloric deficit for long periods of time can be exhausting (although it might increase your lifespan8).
Occasionally increasing your caloric intake, especially via carbohydrates, can:
1. Reduce hunger! This is not only due to the increase in food but also due to the increase in levels of leptin, i.e. the “satiety hormone.”
2. Increase energy expenditure: Although “starvation mode” is a very exaggerated term (and frankly a myth), it is true that your body will decrease energy expenditure as you decrease energy intake9. Occasionally increasing your carbohydrate intake as part of a diet plan via a refeed can help increase energy expenditure2.
3. Make it easier to stick to your diet: It’s much easier to eat at a caloric deficit if you know you’ll be able to eat more in a few days rather than a few months. Refeed days can help you to avoid binging (or dreaming about binging).
4. Make dieting more fun: Okay, maybe dieting isn’t fun. But giving yourself a day to eat more carbohydrates will certainly make it more bearable.
5. Avoid rebounds: We’ve all seen or heard about the competitor who is miserable dieting down for a bodybuilding competition and starts eating everything in sight as soon as the show is over. Refeed days can make for a smoother adjustment to normal life once your diet ends.
6. Increase energy levels, therefore increasing performance levels: Inevitably, fat loss at the level required for competition preparation will come with muscle loss. It’s a constant struggle to increase or even maintain strength levels when dieting for a bodybuilding competition.
Glycogen stores decline while dieting, and occasionally increasing carbohydrate intake can help get glycogen stores back up.
What about Cheat Meals?
Cheat meals and cheat days are kind of like messy refeeds. With a cheat meal, you are still increasing your caloric intake, but the benefits of a cheat meal are mostly psychological.
You might be very happy after eating a burger, fries, and ice cream – especially if the ice cream had hot fudge on top. However, a cheat meal will not have the same physiological benefits as a refeed day would, since you will not be hitting targeted macronutrient levels.
What About Other Approaches to Carbohydrate/Calorie Cycling?
There are several other approaches to calorie cycling. Some approaches, like traditional carbohydrate cycling, are similar to having refeed days. Others take the opposite route.
For example, you might prefer to eat at maintenance all week except for one or two lower calorie days. Although the approach has the same principle of making dieting more bearable with breaks from low days, there will be a different impact on hormone levels.
The impact is that you might not have that “resiliency” that people talk about when they use terms like “metabolic adaptation.”
Should You Incorporate Refeed Days When You Are NOT Dieting?
There is a lack of evidence regarding refeed days while eating at calorie maintenance or at calorie surplus, but we can assume that most of the reasons why refeed days work are still applicable when you are not dieting unless you are eating at a very high calorie surplus.
In other words, refeed days can still help you stick to your diet plan, avoid binging, reduce hunger, and increase performance and energy levels, regardless of your typical caloric intake.
What’s the Point of All This?
Our bodies adapt to dieting, which can slow the process down. Refeed days can help jumpstart the process again by temporarily increasing carbohydrate intake. This can make dieting easier and more “fun” and will make for a much smoother transition into eating at a higher caloric intake when the diet phase is over.
If refeed days only affected one of the many factors discussed in this article, they might not be worthwhile, but the cumulative effect of the refeed day makes it a very powerful tool for fat loss.
Because research on refeed days is both limited and difficult to generalize, there are many different approaches to applying the concept of a refeed. Personally, I have seen success with increasing carbohydrate intake by 50-100% on refeed days. I also like to reduce or even increase fat intake just depending on the individual’s metabolism and response to diet changes.
- Fernández-Formoso G, Pérez-Sieira S, González-Touceda D, Dieguez C, Tovar S. Leptin, 20 years of searching for glucose homeostasis. Life Sci. 2015;140:4-9.
- Dirlewanger M, di Vetta V, Guenat E, Battilana P, Seematter G, Schneiter P, Jéquier E, Tappy L. Effects of short-term carbohydrate or fat overfeeding on energy expenditure and plasma leptin concentration in healthy female subjects. Int J Obes Relat Metab Disord. 2000;24(1):1413-8.
- Ainslie DA, Proietto J, Fam BC, Thorburn AW. Short-term, high-fat diets lower circulating leptin concentrations in rats. Am J Clin Nutr. 2000;71(2):438-42.
- Banks WA, Coon AB, Robinson SM, Moinuddin A, Shultz JM, Nakaoke R, Morley JE. Triglycerides induce leptin resistance at the blood-brain barrier. Diabetes 2004;53(5):1253-60.
- Chow LS, Albright RC, Bigelow ML, Toffolo G, Cobelli C, Nair KS. Mechanism of insulin’s anabolic effect on muscle: measurements of muscle protein synthesis and breakdown using aminoacyl-tRNA and other surrogate measures. Am J Physiol Endocrinol Metab. 2006;291(4):E729-36.
- Pasquali R, Casimirri F, De Iasio R, Mesini P, Boschi S, Chierici R, Flamia R, Biscotti M, Vicennati V. Insulin regulates testosterone and sex hormone-binding globulin concentrations in adult normal weight and obese men. J Clin Endocrinol Metab. 1995;80(2):654-8.
- Chou SH, Mantzoros C. 20 years of leptin: role of leptin in human reproductive disorders. J Endocrinol. 2014;223(1):T49-62.
- Heilbronn LK, Ravussin E. Calorie restriction and aging: review of the literature and implications for studies in humans. Am J Clin Nutr. 2003;78(3):361-9.
- Leibel RL, Rosenbaum M, Hirsch J. Changes in energy expenditure resulting from altered body weight. N Engl J Med. 1995;332:621-8.