Mindy Pelz Fast Like a Girl Review
This Fast Like a Girl review provides my professional opinion about the book Fast Like a Girl.ย
Fast Like a Girl is written by Mindy Pelz, a chiropractor and “nutrition and functional health expert.”
This book focuses on fasting, the act of not eating for extended periods of time in order to achieveโฆ the healing of your cells and body. More specifically, she advocates for cycle fasting, linking your fasting patterns with your menstrual cycle for optimal results.
The beginning of her book has the disclaimer โnot intended to replace personalized medical adviceโฆauthor disclaims responsibility for adverse effects that may result from application of the information contained in this bookโ. This is followed by praise for the book including a long list of alternative medicine practitioners and celebrities, featuring the forward by LeAnn Rimes, a Grammy award winning singer, who unsurprisingly gives us a personal anecdote about how fasting helped her.
There is growing evidence in support of intermittent fasting. However, high quality scientific evidence is limited: much that shows benefit is from rat and other animal studies โ these arenโt always reliably reproduced in humans.
Many of the human studies are quite small, and often done with the express purpose to addressing specific health challenges. Some longer, large, properly controlled studies have failed to show the benefits sought after with the diet. In the human trials that do show benefit, the fasting is supervised medically, with regular blood work and check-ins.
Finally, the concept of linking a fasting cycle with your hormonal cycle, to my research, doesnโt seem to exist anywhere outside of this book.
The introduction by Pelz tells us about her own personal experience with fasting and how it helped her hormones (how does she know this? Because she miraculously felt better after changing her diet).
We know that selling a service or protocol by introducing consumers to it through a personal anecdote, including celebrity endorsements, using popular buzzwords such as hormones, inflammation, and natural healing, is a red flag.
Attributing a sudden miraculous recovery from โchronic fatigue syndrome that made it impossible to do even the simplest daily life tasksโ, to diet, because when the โdepressive haze disappeared overnightโ, this was a direct result the healing power of food, is a HUGE red flag.
This section goes on to blame most chronic diseases on metabolic syndrome, and her solution to โour current metabolic situationโ, is fasting (a single cause for multiple complex issues = red flag).
She assures women they can โflip their metabolic switchโ (this is a commonly-used claim that doesnโt make physiological sense and is more of a marketing ruse) through her program, but warns that โif a woman decides to jump into a fasting lifestyle and doesnโt time that fast to her menstrual cycle, adverse symptoms may appear such as hair loss, rashes, anxiety, missed cycles, thyroid problems, and trouble sleeping. These are all symptoms that can be avoided when a woman learns how to fast for her unique bodyโ.
To me this screams unnecessary potential for great harm, but Iโm just using common sense.
Pelz introduces her two made up food programs, called ketobiotic foods and hormone feasting foods (as if eating isnโt already confusing for the type of person who would buy this type of book, letโs go ahead and invent another couple diets).
She claims that in this book, we will find proven strategies, and condition specific protocols, because she is not selling a one size fits all approach. But I donโt see any reference to a clinical study where she would be able to actually prove her strategies at all; they seem like just her opinion.
The last section of the book provides a โ30 day fasting resetโ, which makes me cringe, because itโs so predictable: alternative health experts who use 30 days as the magic timeline for people to RESET *insert whatever theyโre selling here*.
Just another red flag. Our bodies canโt be โreset.’

Fast Like a Girl PART 1ย
Along with introducing this section using Hippocrates and discussing how he used fasting as a primary healing tool in the 5th century B.C., (I would like to think we have evolved medically since that time), Pelz also highlights that fasting will โincrease autophagyโ (cell death). In this section, Pelz mentions a 2020 study about Covid-19 and claims fasting can help restore autophagyโs ability to shut down viral replication.
Unfortunately, this study is not referenced, the authors name(s) are not provided, and there is also no reasoning given as to why this is even relevant to the book. Pelz claims that โwhen you put your cells into both a state of autophagy and ketosis, [you are] creating an amplified healing stateโ and throughout this section of her book she lists physiologic processes preceded with words like โincreasesโ, โdecreasesโ, โresetsโ and โrepairsโ, to signal that fasting has a positive association with each one: โincreases autophagy!โ, โrepairs the immune system!โ, โIncreases growth hormone productionโ, and the worst of all, โreduces the reoccurrence of cancer!โ.
Throughout this section I found a lot of fancy sounding paragraphs attempting to link fasting as a cure for almost any complex ailment you can think of. The lack of directly cited evidence throughout this section is concerning; Pelz vaguely discusses such a range of complex topics it is difficult to believe someone could be an expert in so many areas and have the research background to discuss all of her claims with such assuredness, especially without the need for citations or references to high-quality studies to back them up.ย
She does have a bibliography by chapter in the back of her book, but without links to each claim, this makes it unbelievably challenging for readers to evaluate the studies sheโs basing her opinions on. How do we know sheโs interpreting things in a reasonable and scientific way?
Not all studies are created equal โ a finding about diet restriction in 6 rats is not equal to a well-designed randomized control trial in hundreds of people. You can find a small study to show almost anything, but that doesnโt mean itโs reproducible, reliable or actionable for us.
I canโt stress enough the importance of practitioners to discuss topics that are within the scope of their area of practice. It is unclear what area Pelz is a qualified expert in. I guess โpioneer in the fasting movementโ will do.
The language used surrounding much of Pelzsโ fasting protocols is alarming. Within the โautophagy fastingโ length fasting of 17-72 hours, Pelz tells readers to think of autophagy as โthis magical eraser that will undo the damage a poor diet created within your cellsโ, and this is after suggesting that a detox is necessary after a โvacation in which you overindulgedโ.
Is this a real science-based book? We canโt โeraseโ food weโve eaten, and to suggest that thatโs possible is incorrect, not to mention disordered. We donโt even know enough about autophagy to make these sorts of claims.
The next few chapters describe clients who have had great results from adjusting their fasting windows and approaches to their menstrual cycle, and a large part of the chapter explains the rises and falls of key hormones women experience during this time.
There is a โsmall study of 15 women with PCOSโ mentioned in here, which I was both happy and disappointed to see. Happy that a study was included (although not cited), but disappointed that Pelz seems to think a study with 15 participants over a short period of time would tell us anything useful or conclusive about anything. Maybe she should get a refresher on what high quality evidence means for her next book.
Fast Like a Girl PART 2
Once I got through part 1, which I would summarize as an advertisement for fasting, we move on to part 2.
In this section, we also learn that Pelz advocates for social media as a great source of health solutions, explaining that โthe upside of social media is that you can teach yourself how to solve many of your health challengesโ, and I am beginning to understand why Pelzโ YouTube channel is plugged so many times throughout this book.
There is a โtoxic ingredients to avoidโ list, including a common rule of thumb in the alternative health community, that โif you canโt pronounce an ingredient, chances are itโs a chemicalโ.
Where have we heard this one before?
There is also a โfoods that support estrogenโ list, and one for progesterone,ย which I donโt understand, because there isnโt any evidence to suggest that broccoli supports progesterone, but cauliflower supports estrogen.ย
I think itโs great Pelz has included such a variety of nutrient dense fruits, vegetables, and legumes, but the credibility train stops when they are separated out into lists based on nothing but an idea.
There is a paragraph about avoiding animal proteins with added antibiotics and growth hormones, and to โalways choose organic, non-GMO and antibiotic and hormone free foods wherever possibleโ. This messaging is so boring and just plain wrong.
I wrote about conventional vs organic here.
Fast Like a Girl Fasting Cycleย
The fasting cycle section of the book starts by saying that when you time your fasts properly you will โstarve off diseaseโ. This is certainly one way to market a fasting cycle protocol.
Is food medicine? Hereโs why I think it isnโt.
Pelz has created three phases within the fasting cycle, which coincide with a womanโs monthly cycle: power phase, manifestation phase, and nurture phase. She includes an anecdote about a woman who fasted improperly and lost her cycle, but then joined Pelzโ Reset Academy online, watched her YouTube videos, and was finally able to fast properly and got her cycle back.
Each fasting phase has a type of diet to follow (either ketobiotic, or hormone feasting), as well as a fasting window (either 13-72 hours for autophagy fasting, 13-15 hours for intermittent fasting, or no fasting at all during the โnurtureโ phase).
It is unclear if there is any real clinical data behind the phases Pelz has created.ย
It’s also important for me to say here, as a dietitian, that I don’t recommend that anyone fast for 72 hours. Or, for that matter, more than 16 hours. And some people shouldn’t be fasting at all, but more on that later.
I see how a plan or protocol to follow that is laid out with graphs and lists can seem appealing. Still, I canโt help but go back to the fact that through all this, we have lost or are in the processes of losing our abilities to listen to our bodiesโ hunger cues and self-regulate.
Fast Like a Girl 30-day fasting reset and โHacksโ sectionย
Here we learn that there is a two-week โpre-resetโ leading up to the actual 30-day reset (that then sets the foundation for a lifetime of fasting cycles).
This is a lot of work for a non-evidence-based protocol. Who has time for this? And, a lifetime of fasting cycles? That sounds like hell.
Thankfully, Pelz assures us that โthere are three easy parts to the pre-reset: foods to avoid, foods to add in, and compressing your eating windowโ. To me this means I am going to eat less often, and with more restriction.
“Foods to Avoid” lists are another red flag.
I am also encouraged to collaborate with my doctor before embarking on this new fasting lifestyle.ย
In the section about compressing the eating window, Pelz assures that โcoffee and tea with a small amount of MCT oil and โclean creamโ can work to kill hunger,โ but advises that โif you like cream in your coffee, make sure if doesnโt have any chemicals or sugar in it as this will spike your blood sugar too muchโ.
Lastly, I canโt not highlight the utter insanity in the paragraph that follows the “clean cream”, where Pelz warns us to โwatch out for food buddies: those women you have bonded with over foodโ. She goes on to give an example of an employee who lost a lot of weight by adopting a new lifestyle where friends who drank Frappuccinos regularly got the boot. Those friends became negative and disgruntled at the employeeโs success, and the employees efforts were derailed and she gained the weight back.ย
I can tell you that the employee didnโt gain weight back because of her friends; in fact, lack of social interaction and friendship can be a reason for weight gain, not the other way around. Advising people to ditch friends over food is terrible advice.
This diet feels like the opposite of listening to oneโs own body- women are instead instructed to ignore their desire to share food with โbuddiesโ and listen to their hunger cues and are instead instructed to rely on Pelzโ opinion, which doesnโt seem to be rooted in clinical data.
We all apparently also need to get new friends who fast. That is ridiculous.
The opening line of a chapter in this section titled How to Break a Fast is โto eat or not to eat- some people think fasting is that simpleโ. I canโt stress enough that EATING can be this simple- and by NOT following a fasting lifestyle, you would be able to SIMPLY decide if you want to eat or not eat based on your bodiesโ hunger cues.
Pelz goes on to tell readers that โas someone who loves to let the science guide me, I was left with little to go on and decided to do my own research. I turned to my community to see what worked best.โ
Pelz is admitting here that she doesnโt actually do proper research; she just decides what works based on the outcomes from her own work, because she has โtestedโ on her own community of thousands of people. This is NOT how research works, and it proves a lack of understanding and huge bias in her work and her opinions.ย
Instead of suggesting we eat food when we feel hunger (because according to Pelz, โhunger is the elephant in the fasting roomโ), she suggests three hacks which I have summarised here: 1) am I hungry or am I bored? She suggests distracting yourself to find out. 2) if you are truly hungry and not bored, try a packet of minerals. 3) try a fasted snack such as an MCT fat bomb. 4) lastly, she suggests a prebiotic powder in water, coffee, or tea.
So if I feel hungry, I should try four different ways to ignore the messaging my body is sending me, instead of just eating a meal. This is an interesting spot to address the next topic: the very last page of this section discusses eating disorders.
Rather than advising anyone who has a history of disordered eating, or an ongoing eating disorder to NOT participate in fasting, Pelz states that โif you have an eating disorder you need to involve your doctor in the process of building a fasting lifestyleโ.
Excuse me? How incredibly harmful. If you’ve ever had disordered eating at all, you shouldn’t go near any type of fasting.
Fast Like a Girl review, in short
I understand how appealing it can be for women to believe that a 30-day fasting reset followed by a lifetime of following a cycle of starving and eating with limitations will change their lives and waistlines, but I canโt stress enough how important it is to think critically whenever you come across books like this one.
This book checks all of the boxes used by every โfunctional alternative health expertโ, including assigning words like clean or toxic to safe foods, mimicking eating patterns of primal ancestors (because they all lived to the ripe old age of ~30), imposing restrictions and rules to eating, encouraging women to ignore their hunger cues in the name of โstarving off diseaseโ, failing to provide high quality evidence for claims, and quite frankly, attempting to undo all the anti-diet work that so many of us are working so hard on.ย
It doesn’t empower women to give them more restrictive diets and unproven information about eating and their bodies. In fact, just the opposite.
I donโt ever recommend these types of self-healing diets, but if Fasting Like a Girl ever gets real clinical trial approval, and the results show that her protocol is safe and provides the results she claims it does, I will happily re-evaluate.