“Carb cycling” has become a new fad, especially in weight-loss-seekers. Today’s post will be a brief dissection of the existing scientific evidence (or lack thereof) surrounding the concept of monkeying around with how and when to eat carbohydrates.

For those of you who don’t feel like reading a whole lot, here is the bottom line up front:

  1. Not enough research exists, at all, supporting the concept of carb cycling for weight loss.
  2. Some research supports the use of carb cycling in highly trained athletes, but even that research is limited. Additionally, a couple things have to be considered:
    1. Many people who are avid exercisers are not the type of “highly trained athletes” these studies were as subjects. (Think actual collegiate/Olympic-type people, not 60-minutes-4-times-per-week-type people…)
    2. Although some trials showed that the athletes did sometimes become better fat-burners, they did so at the expense of feeling super tired during their performance, which isn’t exactly leading to performance enhancement.

In the literature, “carb cycling” is actually referred to as “periodization.” In other words, selecting periods during which you eat a large amount of carbohydrates; then other times when you eat very few carbohydrates. Some look for periodization of carbohydrates to enhance performance; others feel it will be the ticket to weight loss. Either way you look toward carbohydrate periodization, the evidence simply doesn’t support the practice. Sorry.


The idea is that you would first load up on carbs, then do a super-intense workout. Then, you eat very few carbs during recovery and perform very light exercise the next day. Then you lather, rinse, repeat in different increments. The rationale imposed is that you will train your body to rely on burning more fat for performance OR for weight loss by keeping it “guessing.”


Some turn to carb cycling because they have heard that it works like exercise periodization. In other words, some evidence does exist that shows you will build more muscle and/or perform better if you keep the body doing different exercise all the time. This concept can also apply to those with a weight loss plateau (e.g. you have been losing weight for some time now, but you’ve stopped losing before reaching your goal). However, the hypothesis that periodization for carbohydrate consumption will work the same as periodization for exercise falls short.

Some of the research that does promote benefits of periodization, even that concerning exercise, should be looked at with scrutiny. One big systematic review of the literature done in 2015 by Strohacker, et al. showed that exercise periodization was beneficial for adults who previously weren’t exercising. Anything stand out to you? I mean…if you aren’t exercising, but then you start IN ANY FORM (periodization or simply going on a walk)…wouldn’t there be some positive health outcomes? Duh? Is it the periodization, or is it because you got up off your butt? Hmm…perplexing…

Some literature does show a favorable effect of manipulating intake of carbohydrates, such as a review done by Arciero, et al. in 2015. However, they admit that the existing research is hard to compare apples-to-apples, as the variables are far too different. They also note that there are so many individualized factors required for an appropriate diet prescription that a generalized recommendation is not appropriate.


Although most of you will not like what I’m about to say, the fact is that trying to find a new FAD each time your previous FAD fails to help you shed the weight is the problem. Although there may be some merit to reducing (not eliminating) total carbohydrate intake, (especially processed, sugary, yucky refined carbohydrates), it is not the one-stop-shop for weight loss. The issue I see most often is a lack of consistency—a constant flutter from one fad to the next. Try eating whole, unprocessed foods and listening to your body a little more often, and BE CONSISTENT with your efforts.

For more tips, click here and here. If you are hoping for individualized advice, please consider seeking out a registered dietitian nutritionist (RDN). You can find a RDN at many local retail grocery stores, such as King Soopers or Hy-Vee. You can request to see one at many hospitals as well. Make sure they are credentialed with RD or RDN. A personal trainer is a wealth of expert advice for EXERCISE, not nutrition…

As always, I’m willing to change my stance on anything given enough evidence-based information.  I simply haven’t seen it yet regarding carb cycling.

Until next time…xoxo


One thought on “Unicycle…Bicycle…Tricycle…Carbcycle?

  1. […] to completely binge eat and/or binge drink to take a break from your “diet.”  An unhealthy diet is one in which you are constantly obsessed with what you are eating, and one in which you panic at […]


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