One of the more esoteric but much beloved tools in the paleo dieter’s tool-kit is intermittent fasting.
What is intermittent fasting? I.F. is the practice of maintaining overall caloric intake while consuming those calories in fewer meals or in reduced time windows throughout the day. The goal is to create conditions of fasting in the body, but not for extreme lengths of time.
Some examples of intermittent fast strategies include 10, 8, or 5 hour eating windows throughout the day, or perhaps eating just two meals each day: one in the morning, and one at night. The evolutionary premise — the argument that proponents of intermittent fasting make — is that humans evolved to optimize their health under less-than-optimal conditions. Intermittent fasting, they say, is a natural and perhaps even necessary part of being human.
The modern-day scientific correlate appears promising, too:
Most people are nowadays aware that a calorie-restricted diet has the ability not just to decrease body weight but also to lengthen a human life. Emerging research is beginning to show, however, that intermittent fasting is just as effective as calorie restriction in ensuring these health benefits! Amazingly enough, this happens without any of the psychological crippling side effects of cravings and food obsession that practictioners of calorie-restriction often experience.
Intermittent fasting, proponents say, also may benefit the fight against cancer, diabetes, and autoimmunity. Here is an excellent, up-to-date review of the “benefits” of fasting. It is wholly understandable that fasting is all the rage these days.
Intermittent fasting women is a specific interest of mine because of what I have witnessed both in myself and in working with literally thousands of women in the PfW community.
Many women report to me (read more about that in this awesome book) that intermittent fasting causes sleeplessness, anxiety, and irregular periods, among many other symptoms hormone imbalance, such as cystic acne.
I have also personally experienced metabolic distress as a result of fasting, which is evidenced by my interest in hypocretin neurons. Hypocretin neurons have the ability to incite energetic wakefulness, and to prevent a person from falling asleep, in reaction to the body detecting a “starved” state. Hypocretin neurons are one way in which intermittent fasting may dysregulate a woman’s normal hormonal function.
After my own bad experience with IF, I decided to investigate intermittent fasting. I looked into both a) the fasting literature that paleo fasting advocates refer to, and b) the literature that exists out in the metabolic and reproductive research archives.
Intermittent Fasting Women: Problems in the Paleosphere
What I found is that the research articles cited by Mark’s Daily Apple (and others), focus on health benefits such as cancer-fighting properties, insulin sensitivity, and immune function.
However. I was struck by what seemed like an egregious sex-based oversight in that MDA post I linked to above. MDA cites this article as a “great overview” of the health benefits of intermittent fasting. This startled me because the article MDA cited was for me one of the strongest proponents of sex-specific differences in response to fasting.
Sex differences were relevant in two striking areas:
1) women in studies covered by the review did not experience increased insulin sensitivity with IF regimes and
2) intermittent fasting women actually experienced a decrease in glucose tolerance.
These two phenomena mean that women’s metabolisms suffered from IF. The men’s metabolisms on the other hand improved with IF across the board. Recall that the review was reported by MDA as “a great overview of benefits [of IF].”
Secondly, in another fasting post at MDA, of which there are many, the health benefits of fasting are listed and reviewed, but the sex-specific aspects of the hormonal response go unmentioned, and reproduction/fertility/menstrual health isn’t mentioned at all.
This is not to say that Mark is not attentive to who should and who should not be fasting. He knows very well and cautions people against the dangers of fasting while stressed. Still, the mere fact of being more sensitive to fasting simply by being a woman is, I would assert, pretty important for a woman who is contemplating or already practicing IF.
This goes nearly unmentioned in the blogosphere.
Intermittent Fasting Women: Problems in the Literature
Beyond reporting biases in the blogosphere, there remains an even greater problem of a significant testing bias in the fasting literature. Searching “men” + “intermittent fasting” in a Harvard article database yields 71 peer-reviewed articles. Searching “intermittent fasting women” yields 13, none of which are a) solely about women b) controlled studies or c) about more than body weight or cardiovascular benefits.
The animal studies are more equitable, but also a bit less applicable to human studies.
It is well-known in both the research and the nutritional communities that caloric restriction is horrible for female reproductive health. This is not news. There is an infertility condition – called hypothalamic amenorrhea – that millions of women suffer from due to being overly restrictive. But what of fasting?
Intermittent Fasting Women: Should we Fast?
The few studies that exist point towards no.
It is not definitive, since the literature is so sparse, and it necessarily differs for women who are overweight versus normal weight (and who have different genetic makeups), but when it comes to hormones, women of reproductive age may do well to err on the side of caution with fasting.
What follows first is a brief review of what can be gleaned in sex-specific responses to fasting in animal studies. Afterwards I talk about what has been concluded by the few relevant human studies.
Mice & Rats
First up is a study that demonstrates the hippocampal changes of calorie restriction and intermittent fasting for both male and female rats. In this study, they do alternate day fasting, which entails free eating on one day and a fast day on the next.
The study found that brain states while fasting were different for male and female rats. For male rats the change in hippocampus size, hippocampal gene expression, and ambulatory behavior was the same no matter what kind of restricted diet they were on – but for female rats, the degree of change in brain chemistry and in behavior was directly proportional to degree of calorie intake, demonstrating the unique sensitivity of female rats to the starvation response.
” The organization of the females’ response to the energy restricted diets is suggestive of some underlying mechanism that may allow for an organized, pre-programmed, response to enhance survival in times of food scarcity. Comparatively, the males’ genetic response was less specific, suggesting that the males respond to a general stressor but they seem to lack the ability to discriminate between a high energy and low energy stressor.”
Moreover, “IF down-regulated many gene pathways in males including those involved in protein degradation and apoptosis, but up-regulated many gene pathways in females including those involved in cellular energy metabolism (glycolysis, gluconeogenesis, pentose phosphate pathway, electron transport and PGC1-α), cell cycle regulation and protein deacetylation.” In this study, both male and female rats gained small amounts of weight on IF diets.
For female rats, even in the most innocuous form of restriction–intermittent fasting–significant physiological changes take place. Male rats do not experience as dramatic hippocampal and general brain chemistry change as female rats do, and their behaviors, specifically their cognition and their dirunal and nocturnal activity, do not change.
Female rats, on the other hand, “masculinize.” They stop ovulating and menstruating. They become hyper-alert, have better memories, and are more energetic during the periods in which they are supposed to be sleep. Theoretically, according to these researchers, this is an adaptive response to starvation. The more the female rats need calories– or at least the more their bodies detect a “starvation” state– the more they develop traits that will help them find food. They get smart, they get energetic, they get active, and they stop sleeping.
In a follow-up study conducted by the same researchers who explored the masculinzation of female rats, the researchers analyzed the gonadal transcription of male and female rats subjected to IF regimes.
This study found that male reproductivity up-regulates in response to metabolic stress. Female reproductivity down-regulates.
Completely opposite to the female rats becoming infertile while fasting, male rats become more fertile. In the researchers’ own words: “our data show that at the level of gonadal gene responses, the male rats on the IF regime adapt to their environment in a manner that is expected to increase the probability of eventual fertilization of females that the males predict are likely to be sub-fertile due to their perception of a food deficient environment.”
In the final relevant IF rat study I could find, researchers subjected rats to the same diets– to 20 and 40 percent Calorie-Restricted (CR) diets, as well as to alternate-day fasting diets, and monitored them over the long term for hormonal responses. The results were striking. Below is the abstract in full because it’s so powerful:
Females and males typically play different roles in survival of the species and would be expected to respond differently to food scarcity or excess. To elucidate the physiological basis of sex differences in responses to energy intake, we maintained groups of male and female rats for 6 months on diets with usual, reduced [20% and 40% caloric restriction (CR), and intermittent fasting (IF)], or elevated (high-fat/high-glucose) energy levels and measured multiple physiological variables related to reproduction, energy metabolism, and behavior.
In response to 40% CR, females became emaciated, ceased cycling, underwent endocrine masculinization, exhibited a heightened stress response, increased their spontaneous activity, improved their learning and memory, and maintained elevated levels of circulating brain-derived neurotrophic factor. In contrast, males on 40% CR maintained a higher body weight than the 40% CR females and did not change their activity levels as significantly as the 40% CR females. Additionally, there was no significant change in the cognitive ability of the males on the 40% CR diet.
Males and females exhibited similar responses of circulating lipids (cholesterols/triglycerides) and energy-regulating hormones (insulin, leptin, adiponectin, ghrelin) to energy restriction, with the changes being quantitatively greater in males. The high-fat/high-glucose diet had no significant effects on most variables measured but adversely affected the reproductive cycle in females. Heightened cognition and motor activity, combined with reproductive shutdown, in females may maximize the probability of their survival during periods of energy scarcity and may be an evolutionary basis for the vulnerability of women to anorexia nervosa.
They also found this:
The weight of the adrenal gland was similar in rats on all diets; however, when normalized to body weight CR and IF diets caused a relative increase in adrenal size, the magnitude of which was greater in females, compared with males.
The testicular weight was unaffected by any of the diets. In contrast, both CR diets and the IF diet caused a decrease in the size of the ovaries.
And this, bearing in mind that “daytime” for nocturnal rats is “nighttime” for humans:
The daytime activity of females was doubled in response to IF, whereas the IF diet did not affect the activity level of males. Nighttime activity levels of males and females were unaffected by dietary energy restriction.
Uterine activity was monitored daily with vaginal smear tests; cyclicity was scored as regular, irregular, or absent. The mild energy-restriction diets (20% CR and IF) significantly increased the proportion of animals displaying irregular cycling patterns, whereas the 40% CR animals displayed an almost complete loss of estrous cyclicity.
In males, corticosterone levels were elevated only in response to the 40% CR diet, whereas in females corticosterone levels were significantly elevated in response to all three energy-restriction diets, suggesting a relative hyperactivation in females of the adrenal stress response to reduced energy availability.
For lipids, all the rats did well: “Collectively, these data suggest that atherogenic profiles of both males and females are improved by dietary energy restriction.” Interestingly, too, as they pointed out in the abstract, human females also perform cognitively much “better” (memory and alertness) on CR and IF diets than on normal feeding schedules.
There are of course some caveats to this study: A) They are rats. B) They are somewhat “metabolically morbid” rats, which may make them more susceptible to disease. C) The rats were allowed to eat ad libitum on the IF days, but they simply did not meet their caloric requirements this way. So while it is a somewhat natural form of IF, it is still calorically reduced, such that that must be taken into account when gasping in horror at the hormonal responses of IF-ing female rats.
The Few Human Studies
I mentioned above that through the same review that MDA used as a “great overview” of IF benefits for all sexes, I found harmful metabolic effects for women subjected to alternate-day fasting regimes.
This is the study:
Heilbronn et al found that with IF, insulin sensitivity improved in men (21 participants) but not in women (20 participants): after three weeks of alternate day fasting, insulin response to a test meal was reduced in men. Women experienced no significant change. “It is interesting that this effect on insulin sensitivity occurred only in male subjects,” they report.
With respect to other health markers female health actually declined, specifically with respect to glucose tolerance:
“Another diabetes risk factor that has shown a sex-specific effect is glucose tolerance. After 3 weeks of ADF, women but not men had an increase in the area under the glucose curve. This unfavorable effect on glucose tolerance in women, accompanied by an apparent lack of an effect on insulin sensitivity, suggests that short-term ADF may be more beneficial in men than in women in reducing type 2 diabetes risk. ” The opening line of their discussion reads: “Alternate day fasting may adversely affect glucose tolerance in nonobese women but not in nonobese men.”
In a follow up study, Heibron et. al studied the effects of alternate-day fasting on cardiovascular risk. When human subjects fasted on alternate days for another three week period, circulating concentrations of HDL cholesterol increased, whereas triacylglycerol concentrations decreased. This is a good thing. However, the shifts in lipid concentrations were shown to be sex specific: ie, only the women had an increase in HDL-cholesterol concentrations, and only the men had a decrease in triacylglycerol concentrations.
The most recent review of IF agrees with my conclusion: sex-specific differences in metabolism exist and need to be studied further.
This study of alternate day fasting included 12 women and 4 men. In eight weeks, body weight decreased by about 10 pounds, and body fat percentage decreased from 45 to 42. Blood pressure decreased, total cholesterol, LDL cholesterol, and traicylglycerol decreased. These people were significantly obese, which limits the results of this study to an obese population. However, “perimenopausal women were excluded from the study, and postmenopausal women (absence of menses for >2 y) were required to maintain their current hormone replacement therapy regimen for the duration of the study.” (Their words, my emphasis)
The one, big study of intermittent fasting conducted on men and women looked at differences between isocaloric feeding schedules: 3 meals/day feeding versus 1 meal/day.
The study focused on body weight composition, blood pressure, and body temperature in subjects. Subjects were fed isocalorically either one meal each day or three meals each day. All subjects were between 40 and 50 years old (excluding women of reproductive age), and between BMIs of 18 and 25. They ate, so far as I can tell, a healthy diet with 35 percent fat, PUFA < MUFA < SFA. Only 15 of the original 69 completed the study (which goes to show just how fun everyone thought fasting was). As for the results,
“Systolic and diastolic blood pressures were significantly lowered by ≈6% during the period when subjects were consuming 3 meals/d than when they were consuming 1 meal/d. No significant differences in heart rate and body temperature were observed between the 2 diet regimens. Hunger was enormously larger in the one meal/day than in the three meals/day group. “The 1 meal/d diet was significantly higher for hunger (P = 0.003), desire to eat (P = 0.004), and prospective consumption (P = 0.006) than was the 3 meals/d diet. Feelings of fullness were significantly (P = 0.001) lower in the 1 meal/d than in the 3 meals/diet.” Body weight dropped only four pounds after several months. Cortisol dropped, but Total, LDL, and HDL cholesterol were 11.7%, 16.8%, and 8.4% higher, respectively, in subjects consuming 1 meal/d than in those consuming 3 meals/d.
In sum: patients on the one meal/day regiment were unhappy, hungry, lost a little bit of weight, increased cholesterol. This was a small sample, included somewhat menopausal women, and all people of normal body weight.
Intermittent Fasting Women: In Conclusion
All that being said, that’s it. That’s all that exists! Women don’t have much to go on.
There are a few rodent studies. They found that when alternate-day fasting,female rats and found significant negative hormonal changes occurring in the females.
There are even fewer human studies. Human studies on alternate day fasting have not been conducted on women of reproductive age at all, nor have any studies analyzed reproductive responses to fasting.
Moreover, the few studies that have been conducted on non-obese women have demonstrated that their metabolic responses are not nearly as robust as those of men, and may in fact be antagonistic to their health.
This post has focused on sex-specific responses to fasting, specifically intermittent fasting women. Another important distinction to make is between different body weights. Overweight and obese patients appear to experience significant improvements with IF regimes, but normal weight patients do not show the same across-the-board benefits. For women this may be a particularly sensitive issue. Overweight women may experience metabolic benefits, whereas normal weight women do not. I suspect that that may roughly be the case, but who knows. Honestly, no one at this point.
The practical solution, then, I believe, is to look at options, to be honest about priorities, and to listen to one’s body with awareness and love.
Is fasting worth trying if a woman is overweight and trying to improve her metabolic markers, and so far hasn’t had much success? Perhaps. Should it be undertaken if a woman is of normal weight? What if she is a light sleeper? What if her periods begin to dysregulate? Or stop? What if she starts getting acne, getting a stronger appetite, or losing her appetite altogether? These things happen, and I see them in women who fast and contact me time and time again.
We women (people!) should be honest with ourselves about our priorities, and act constantly with our mental and physical health foremost in our minds. All women are different. But the literature is so sparse in this area that we cannot make any real statements or predictions about the effects of fasting, other than that we just don’t know, and that we should continue to emphasize the centrality of awareness, caution, and loving nourishment in moving forward.
IF is one realm in which the female body has unique characteristics and needs that demand attention. There are boatloads of others. If you’re interested in reading about the collective set of them and learning how to optimize female skin, weight loss, and hormone balance, for a few examples, you could do worse than my best-selling book, Sexy by Nature, here.
And that’s a wrap! What do you think?
I would say about ⅓ of the questions that come through for our podcast or email have something to do with understanding why our eating patterns are restricted. Or, questions regarding restricting and really, deep down knowing restricting is harmful to our health, but being unable to reflect or accept that fact without the feedback or acknowledgement of others. Which is OKAY. I have been there so many times before, too.
For example, when there is a question along the lines of, “I exercise “x” times a week and eat 1200 calories a day, but have “x” health problems, could this be originating with my calorie deficit?”. A lot of these inquiries are answered by the person asking in the question, but sometimes we need to hear confirmation from others that these things are affecting us negatively.
That is also why referring to ourselves as third person is a common way to gain perspective and insight on things that may be troubling us or if we are looking for insight on what we really need.
I too, have reached out to doctors, research, and my friends or family to understand why my body responds the way it does, or more importantly, why my body isn’t responding the way I want it to. We need to understand why our bodies don’t want to shed weight, recognizing that things like stress and inflammation can cause our bodies to enter a state where shedding weight isn’t the priority in keeping our body functioning. In a way, our bodies have a mind of their own and will make decisions to take care of themselves, even if we think we already are.
Processing and challenging our disordered thinking is not an easy task; in fact it is one that requires consistent work. I have to be mindful daily to make sure I am not falling into my past negative restrictive habits. This journey is a long one, and may often feel like you are taking 8 steps back and only a half step forward some days.
As with most people, I find that there is an ebb and flow of my moods and habits, and surrounding myself with positive people, eliminating negative social media outlets, and incorporating techniques like Cognitive Behavioral Therapy into my daily life can be grounding.
So – how can we use CBT to manage disordered eating?
What is CBT?
CBT is an evidence based treatment model focused on how our thoughts, feelings, environments, and behaviors are intertwined, and that they can be restructured to support better habits and actions. This type of treatment has been used for anxiety and depression in the past, but more so has been used for eating disorders and disordered eating patterns recently.
There are three phases to CBT – Behavioral, cognitive, and relapse/ maintenance. Each phase is targeted on different approaches to break down our existing thoughts surrounding restrictive or disordered eating. If you are interested in reading more on the specific phases, check out this book.
So How Can CBT Help?
The first portion of CBT is understanding why we have developed the patterns that we have. This stage is to gain a grasp on why we have developed the patterns that we have, and educating ourselves on the science behind disordered eating. In order to proceed with healing, we must understand how and why our brain’s have become wired to restrict the way we do.
- Setting Meal Times
This may seem counter intuitive, but it is an effective step in CBT. When we have regularly scheduled meal times at realistic intervals, we know when we will be eating again and as a result are breaking up the controlling binge restrict cycle that so often is in place.
- Challenging Our Dietary Rules
This one is commonly discussed on our podcast, and I find so many women have some sort of dietary rules in place. A few of mine included : eating heavier meals in the morning in order to have the rest of the day to burn it off, not eating after 9 PM, eating carbs throughout the work day, etc. So with these rules we need to challenge them by reversing our thoughts on them. This can include eating a light breakfast and heavier dinner, in my situation. What dietary rules do you have that you are willing to challenge? Did you ever tell yourself a food was off limits, and if so, why? Try eating that food and really reflect on how you feel in that moment. This brings me to our next item.
- Confront and Expose Fear Foods
After the above steps have been incorporated, the next gradual step is to give yourself the permission to expose our fear to food. Part of this is removing the fear from food itself, and understanding food is just food. There is no evil cookie out there, the reason we see the cookie as evil is because of the negative connotation WE place on the cookie. If we remove the fear of eating the cookie, it becomes just that again.
This helps often with those that experience binging or purging. If we got caught off guard in the middle of an area that we are wanting to binge or purge, say by a call from a loved one, or an unexpected immediate deadline, we usually are able to push back our binging which can often lead to no longer feeling the need to binge after the stressor has passed. I would recommend creating a list of things to pull out of your back pocket that can intercept restrictive behaviors. This article has a great list to start with that includes doing your nails, playing with a pet, calling a friend, or listening to music. By allowing yourself to complete this task before indulging the negative behavior, we can catch and stop that negative behavior from happening.
- Continue to Self Monitor
By journaling (this is a great workbook) and keeping track of consumed foods along with emotional feelings we can reflect on what ultimately is causing us to feel restrictive patterns in that moment. For instance, journaling at lunch time at work describing your current mindset and what your eating can allow you to see if you are stressed out about a project at work. Over time, journaling can show us what patterns we have surrounding our mindset. Maybe we only feel binging behaviors when we are stressed at work, or maybe the binging is at home before bed. This step is about maintaining self awareness and really “knowing thyself”.
By no means am I a registered, educated or licensed professional when it comes to CBT. I write purely from my own personal experience and research, and from my research working with women through PfW. All of these tips can be extremely helpful while navigating the world of CBT. However. CBT doesn’t work for everyone, especially when trying to complete on your own.
I was able to utilize CBT to manage disordered eating in the most effective way by utilizing a local mental health professional. CBT takes consistency to be fully optimized; by working with a professional you are more likely to have a successful experience with CBT. To locate a therapist that specializes in CBT, click here.
This website is the holy grail of resources. It contains informative handouts on eating disorders and disordered eating habits, as well as handouts, worksheets and exercises. There is also an extensive further reading page.
This website has a series of in depth modules that walk you through the CBT process.
As always, let me know if you have any questions or concerns or if I can help in any way. Everyday we are one step closer to eliminating restrictive eating if we consistently work towards improving. Keep an eye out for a few future posts on additional ways you can work to eliminate disordered eating tendencies.
One of the most common problems I encounter in my audience is binge eating. This is also one of the most common concerns Noelle and I field for our podcast. Everybody wants to know: How do I stop?
I have written about overcoming binge eating at great length before. In the article Binge/Restrict: The Most Common Pattern of Overeating and How to Stop, for example, I argue that while most people think the solution to binge eating is simply to be disciplined enough to get over it, the answer is actually the opposite. The answer, I argue, is to allow yourself abundance. The answer, I argue, is lots of food. Once you stop restricting your diet, you no longer feel the deprivation and obsession that inevitably cause you to overeat later on.
I do still believe that this is one of the most important things you can do to overcome binge eating. But I would like to discuss here the great, biochemical heft behind these processes.
Because here’s the thing: as much as society (and you!) may call you undisciplined, stupid, lazy, gluttonous, fat, insert demoralizing adjective here, for bingeing on whatever kind of food has hooked you, it’s wrong. It’s just plain wrong. You’re up against a huge set of biological, habituated compulsions. Bingeing behavior has now been proven to have potent biological motivators. And you must know it. I believe — I hope — that as you know it, so you may forgive yourself. Then you may more easily walk the path of healing.
To that end, I am going to describe two separate studies. These were both done on rats, so of course we cannot assume they to apply to humans. But there are human analogues and other human studies (such as on the science of sugar addiction – a topic for another time), that indicate the models may well apply.
Binge-Like Consumption of a Palatable Food Accelerates Habitual Control of Behavior and Is Dependent on Activation of the Dorsolateral Striatum
This study investigates the difference between constant, non-restricted access to palatable foods versus restricted access to palatable foods. It ends up revealing that just a few weeks of occasionally being exposed to bursts of sweetened milk cause rats to binge on it, as well as to maintain these eating habits even after the time restrictions have been taken away. It happens because of neural changes that have taken place during the “burst” period. These changes cause long-term habits to form.
Teri Furlong and colleagues at the University of Sydney gave rats a diet of either normal chow or chow plus sweetened condensed milk. The “normal chow” rats were the control group. The rats that received the sweetened milk were divided into two groups: half got milk all day every day, as much as they wanted. The other half got access to the sweet stuff for only two hours every day.
After five weeks, the scientists trained all of the rats to press levers. There were two levers: one for sweet sugar pellets and one for simple grain pellets. In the test, the animals feasted on one of the types of food (either the sugar or the grain) and then exposed to a lever. In the first scenario, rats saw the lever for food they hadn’t yet had. If they had eaten sugar, they got grain. If they had eaten grain, they got sugar. In this scenario, all the rats ate a lot of the new food. Tastebuds like variety.
In the second scenario, the rats were given access to levers for the food they had already eaten. So if they had eaten sugar, they got a lever for sugar, and if they had eaten grain, they got a lever for grain. And this is where things really get interesting: rats who had had constant access to the sweetened milk in the training phase ate to satiety. They stopped pressing the lever. They had no interest in either the grain or the sugar. But, rats who were only allowed access to the sweet milk for two hours a day (and for the rest of the day, as much unsweetened food as they wanted), responded differently. They kept pressing for grain, even though they were already full of grain, and they kept pressing for sugar, even though they were already full of sugar. They weren’t pushing these levers because they were hungry. They were pushing these levers because having restricted bouts of access to sweet foods rewired their brains.
Interestingly enough, the researchers found that the obsessive lever-pressing was associated with an area of the brain called the dorsolateral striatum–an area of the brain associated with habitual behaviors. The researchers therefore hypothesize that rats develop long-lasting bingeing behaviors because of the repetitive training they had from the easier phase of the study. In that phase, they simply learned that the sweet stuff was rarely available, so they stuffed their faces when they could. This imprinted in them a long term habit.
Importantly, chemicals injected into their brains that interfered with glutamate and dopamine activity in the dorsolateral striatum caused the bingeing behavior to stop.
In this study, MM Hagan and DE Moss subjected rats to four different patterns of 12-week restriction-refeeding cycles. The animals were either food restricted–constantly on a diet–or restricted plus some free-access binge days. After 12 weeks all rats underwent a re-feed period.
There were four different groups of rats: 1) “normal diet” eating with normal chow in the refeed period, 2) cyclical restricted eating (bingeing) with normal chow in the refeed period, 3) “normal diet” eating with palatable food in the refeed period, and 4) cyclical restricted eating (bingeing) with palatable food in the refeed period.
The rats that ate the “diet eating” consistently received 75% of their normal calorie intake. The rats with cyclical restricted eating went through 4 days of restriction of 75% of their normal intake, then two days of a refeed where they could eat ad libitum.
After 12 weeks of this kind of entrainment, the rats were given 3 tests: 1) 24 hour deprivation and chow feeding; 2) 24 hour deprivation then chow and cookie feeding; 3) spontaneous chow and cookie feeding.
In the first test, with 24 hour deprivation and chow feeding, the rats which had gone through restricted cycles of feeding (on both normal and sweet food) ate 10% more food than the control rats. Interestingly enough, the rats that had been conditioned on sweet food were not all that interested in the chow feeding, and actually ate 20% less chow than the control group.
In the second test, with 24 hour deprivation and cookie feeding, rats that had been in sweet restricted cycles ate almost 20% more food than the control group.
In the third test, in simple spontaneous feeding without a 24 hour deprivation window, rats conditioned by sweet foods ate more than rats on normal chow, regardless of whether they had been restricted or not. The rats who ate non palatable chow and were on normal “diets” were perfectly fine; the rats who had eaten sweets but were on a normal diet ate about 20% more; the rats who had been in restricted cycling patterns and refed on sweets ate 80% more than control mice on normal diets. 80% more.
Researchers in this study conclude, therefore, that “of all the conditions, the restricted/palatable group showed the most bulimic-like eating behavior. That is, a history of restricted eating (dieting) and refeeding on palatable food (bingeing) predicted a persistence of bingeing-eating behavior even after a 30-day period of normalization.”
Other Studies and implications
Of course, these are just two studies, and have been conducted on rats. There are plenty of indicators that similar phenomena are at play in human beings. Recall perhaps most strikingly of all the Minnesota semi-starvation experiment in which “normal men” were food restricted and showed binge eating and insatiable appetites for sweet foods even after many days of unrestricted eating during the rehabilitation phase (Franklin et al 1948). In the 90s, Polivy et al “found that uncontrollable bouts of binge eating were significantly more common among prisoners of WWII who had, over 50 years earlier, experienced severe food restriction compared with nonrestricted combat veterans” (1994).
Via experiments on rats, we can see more clearly mechanisms by which this takes place. Apparently, pleasure neurotransmitters (such as dopamine) are definitely involved, as are, to a significant extent, the parts of the brain that are associated with habit formation.
The bottom line is this: your history of dieting, of binge eating, of restricting and refeeding, has had a concrete affect on the functioning of your brain. I can’t tell you how many thousands of women have expressed terrible guilt and shame with respect to their bingeing behaviors. They are all incorrect. If you feel this way, you are also incorrect. Your biology compels you, and powerfully so.
As I indicated in the start of this post, literally the best thing you can do for yourself is to forgive yourself. Give yourself access to food, and unlimited. Accept your body and delight in how hard it tries for you. Provide it with the nourishment it needs to develop new habits. It may feel rough at first, but over time the body can actually learn to eat well. You may also find that staying away from sweets or certain palatable foods is important. So long as this does not cause you to develop obsessions with these foods, that could be good. It would remove the biological trigger of habit that you have imprinted in your brain. Even switching to a different set of palatable foods could help (so long as your access is unrestricted). They key here is developing a positive, loving, forgiving attitude and helping your body create new habits.
You may also wish to supplement with low doses of l-tyrosine and/or l-tryptophan. These are precursors to dopamine and serotonin, respectively. They have been demonstrated to sometimes be quite potent for curbing people’s compulsions to overeat (an argument famously made by Julia Ross in The Diet Cure). I have personally noticed that when I take L-tryptophan (I take it for sleep) my constant feeling of “I could eat” disappears, and I feel more like a “normal person.”
Do you have experience that lines up with what I’ve discussed here? Contradicts it? I’d love to hear about what you’ve gone through, and anything you share could be a great help to someone else in the community.
Did you know that there are actually three different major types of eating issues?
There are eating disorders, disordered eating, and then something similar to disordered eating called ‘problematic eating behavior’.
One of the interesting types of problematic eating behavior seems to describe MANY of the people that I talk with in the nutrition world and many of my readers- they are called restrained eaters.
Restrained eaters are eaters who struggle with chronic restrictiveness- either eliminating foods or chronically dieting.
If you are a yo-yo dieter or find yourself continually in the cycle of losing or gaining weight, you may be a restrained eater.
When restrained eaters are confronted with weight gain, they feel negative emotions which can then cause them to overeat. They also feel guilt when they eat a food they’ve deemed “bad”. Restrained eaters also have an obsession with body shape and weight and may use self-judgement as a tool to spur their weight loss goals.
Sound a little familiar?
In the paleo community, we eliminate certain foods for health reasons. In other forms of dieting we restrict processed foods or calories to help lose weight.
Research shows that these things DO help people lose weight. But research also shows that restrained eating can actually promote eating disorders.
Approaching weight loss from a perspective of restraint and negativity- the “i’m getting so fat I’ve got to lose weight” mentality, is a moving target. Nothing will ever be good enough. And when/if it is, it won’t last, because the way we get there is unsustainable.
Now, I know some people who do make restrained eating a lifelong change and feel great.
But there’s a difference.
These people restrict certain foods not because they are afraid of them (i.e. GRAINS and CARBS), but because they are making other choices that are healthier for them.
They are thinking about what foods they can eat to be as healthy, happy, and energetic as possible. They are approaching restraint from a POSITIVE perspective.
With these people, it’s not about eating as few carbs as humanly possible, it’s about eating how many feel right.
Of course there’s always the disclaimer that our modern world of processed, hyperpalatable foods makes knowing how many carbs are right difficult. And some people struggle with conditions like insulin resistance that make unhealthy carb cravings REAL.
But for most eating all whole, unprocessed food, there’s no reason to be afraid!
Research shows that these positive eaters have higher self-esteem and better long term weight management success.
My friends will tell you that they have an emotional freedom they never had before as well.
It just worries me in this day and age of “keto”, which is basically paleo circa 2011, being masqueraded as the all-powerful life changing, freedom giving lifestyle, that so many of these people are just restrained eaters on another diet.
25 grams of carbs is not right for many women. It’s just not. And obsessively tracking and counting them is just the kind of behavior that leads to chronic dieting.
How do we break that cycle?
It’s both easy and hard.
It requires turning to a type of eating called intuitive or mindful that focuses on listening to the body, to what it needs and what it wants, listening to the emotions that so often control us and taking everything in without judgement.
From there, we make food choices. We don’t count macros. We just listen and lovingly try to make each meal and food choice about HEALTH and NOT about weight.
That sounds too easy for most restrained eaters. They want to track, count, weigh, obsess and ruminate. I’ve been there too.
But the truth is, it sounds too easy because it actually is really, really hard.
A restrained eater is often not as self-aware or in touch with themselves as they think they are. They don’t know how to navigate health without a map of good and bad foods to guide them. The vast world of food choices is scary and they are afraid, above all, of gaining weight or staying in one place.
But it does represent a way out. Still restrained? Sure. No one’s recommending you binge on twinkies. That’s not the point. A mindful body will rarely ask for twinkies.
But if it does ask for chocolate sometimes or an apple? Or even *gasp*, a potato? A mindful eater will eat, without self-judgement. They will also probably choose more fruits and vegetables and crave less fast food.
Want to give it a try? I made a program to help you do just this. It’s called Weight Loss Unlocked and you can find it here.
Either way, I want you to know that I’ve fought this battle and I know how it feels.
I know the pain of those self-judgments and I can tell you I’d rather be the weight I am now, whatever it is, and be this happy and free, than be constantly angry and mean to myself for not being a weight that isn’t right for me.
True diet freedom is never having to be on a diet, even one cleverly disguised as a lifestyle, again.
Do you struggle with restrained eating? How do you overcome these issues?
Today I want to talk to you about a very sensitive and challenging issue.
It’s an issue I see constantly. I get emails daily from women who struggle with this stuff.
And it SUCKS.
I see too many women in my life constantly battling with food and their weight.
Is that you?
If it is, I want to talk to you!
I want to talk to those of you who are constantly searching for the perfect diet, and constantly falling off the perfect diet.
Are you constantly swinging between “this time I’ve got it,” and “what the hell is wrong with me that I can’t stop eating peanut butter out of the jar?”
Are you always judging yourself based on what you ate that day or whether or not your skinny jeans fit?
Do you generally let food and weight concerns rule your world — the ups and downs of the diet-binge cycle dictating your “good” or “bad” days.
I’ve lived this stuff.
I’ve lived a life that revolved around the food I put in my mouth, the exact quantity and macronutrient profile.
I’ve lived a life of food obsession and poor self-esteem.
Isabel Foxen Duke, my friend and founder of Stop Fighting Food, calls this “feeling crazy around food.”
Isabel is one of the most well-respected pros in the emotional eating world, contributing some very new ideas about how we can change our thought-patterns around food and weight, and finally break out of the exhausting diet-binge cycling behaviors that too many women find themselves trapped in — behaviors like, sneak-eating ice cream in the middle of the night; yo-yo dieting; emotional eating, and emotional eating’s painful cousin:binge-eating.
Many of my readers have worked with Isabel and her programs and have found her to be uniquely supportive and able to help them understand what is going on in their minds, and get back on the right track.
She’s got a wonderful, witty perspective that will keep you laughing and she drops truth bombs like nobodies business.
Isabel’s offering a free video training series this month, (Find it here) covering some of her most important concepts in changing women’s relationship with food on an emotional and psychological level.
If this is a topic that speaks to you, I highly recommend you sign up to get her free vids.
You don’t have to live your life clinging desperately to diets, only to end up with your fingers in a jar of Nutella at the end of the day.
You don’t have to live the rest of your life feeling bat-shit crazy around food.
Here’s the link again to sign up for this free training.
Let us know how you try to fight feeling crazy around food!
Woah, 2017. I can’t believe you are almost here!
At the writing of this blog post I’m pondering the making of new years resolutions. Are they healthy? Are they harmful? Are they something in between?
I’ve gone back and forth, but concluded that, like them or not, new year’s resolutions are a part of our culture, exciting and important motivators that can give someone the push they need to make valuable and lasting changes.
I’m not into crash dieting (or “diets” of any kind really) and I’m not into resolutions that end up making people feel worse about themselves when they fail to live up to unreasonable standards.
But health IS important, and focusing on feeling better and doing better in the new year is something admirable, after all.
So here’s my list of 5 Paleo for Women Approved New Years Resolutions!
#1 Cook More
Cooking is something I usually despise doing and avoid if I can help it. But it gets old eating canned salmon all the time.
As the new year begins, take some time to plan a daily schedule.
If you’re a detailed list maker, you’ll love it and if you’re not, you might feel caged in, but sketching out your time might show you ways you can be more efficient and leave room for home cooked meals.
Try buying books with meal and shopping plans already inside for you. Practical Paleo (find it here) is one of my favorites, because it contains meal plans for every possible variation of paleo.
There are other great books too. Stick with ones that focus on easy recipes that can be made quickly like Well Fed Weeknights (find it here). Or try books that utilize less dishes for easier cleanup like One Pot Paleo or Paleo Slow Cooker.
Cooking more will mean eating more veggies, one of the biggest indicators of a healthy lifestyle, and will cut down on the amount of rancid oil, sugar and Omega 6 you eat, making you feel healthier, improving skin and cardiovascular health, and probably helping you lose some weight.
#2 Lose Weight
Speaking of losing weight…
I might catch some flack here. You see, I believe strongly in body positivity and the body positive movement. That means I do hold firm to a belief in health at every size.
However, I also believe that weight loss can be a valuable goal for certain people.
Excessive adipose tissue does produce inflammatory responses in the body and does contribute to a range of health issues. And whether we like it or not, it IS something that we need to consider in our modern world of convenience foods and obesity related illness.
If you’ve become out of sync with your body, feel you need to lose excessive body weight (and remember that doesn’t mean you need to be stick thin!) the only real difficulty is finding a way to do it gently, positively, and with as little guilt and shame as possible.
That’s where my weight loss program, Weight Loss Unlocked comes in.
It’s designed to help you lose weight efficiently but mindfully, learning to listen to the natural signals of your body, rather than the mean girl in your head.
It can help you follow those New Years Resolutions without the fad dieting that normally goes with it. I’d suggest pairing it with a great paleo cookbook with meal plans like the ones I mentioned above.
Find Weight Loss Unlocked Here.
#3 Focus on Self-Love
While most people choose to lose weight at the beginning of the new year, it’s just as important to choose to love.
We often become our worst enemies and meanest critics, beating ourselves up and tearing ourselves down.
Disordered eating, low self-confidence, so many things stem from not loving ourselves.
To give and recieve love in the new year, we’ve got to start with healing our own hearts.
There are many, many people out there happy to help you do it.
To discover the sexy, confident woman you really are, try reading my book Sexy By Nature.
If you’ve strugged with disordered eating and are ready to take control of negative thinking, try my friend Kayla’s program Starting the Path to Recovery and Discovery here. Try reading When Food is Love (find it here), a classic for any emotional eater.
If you’re shy, perhaps try pushing yourself to do something that sounds fun but makes you a bit nervous- go out dancing or join friends at a party.
And if you’re always out to avoid being alone at home, perhaps try a night in of reflective thinking and journaling (Let it Out is a great resource) and sit with some of those emotions.
You’ll gain self-awareness and balance which we all could use in the new year!
#4 Breathe More
Breathing is something we do far too often without really thinking about it.
Most of us don’t even use the full capacity of our lungs, but only a tiny portion of them.
And breathe, just like food, is so important to life itself, and quality of life.
Improper breathing can do damage to the body just as poor food choices can.
Proper breathing, taking deep, long breaths, and long, smooth exhalations, can also be a form of meditation that has been shown to reduce stress, calm the nervous system and relax the mind.
It’s an imperative especially for those with anxiety, and may help anyone with stress-flaring conditions like Irritable Bowel Syndrome, autoimmune conditions, and more.
With the new year, I’m vowing to remember to breathe in positivity and breathe out negativity. I hope you’ll do the same.
#5 Let Go
And as I work to breathe out negativity, I’m going to be trying my best to let go of anger, expectations, and arbitrary standards I place on myself and others.
2016 was a hard year for many and it’s easy to pick out the bad things that happened and let them stew and boil within us.
We can focus on that negativity, that anger, and let it fester.
Or we can consciously make the choice to let it go.
I don’t have a 3 step program to help you do that (though I’m sure one probably exists!) but I think we should try it nonetheless.
Let’s focus our hearts and minds on the good in 2017 and work for peace, justice, and positivity in the new year.
I will. I hope you will too.
What are your new year’s resolutions?