My 5 Days on the Fasting Mimicking Diet

By Leigh Wagner, PhD, MS, RDN

If you follow me on Instagram, you may have seen that I did my second round on the fasting mimicking diet this past week, after doing it for the first time last November. I gave a few quick glimpses of it in my instagram stories but wanted to do a deeper dive into the program here. 

First, I want to give you the background and make it clear this is not a sponsored blog post (#ipaidforthis). I want to share with you the science behind the program, what it is, and who should and shouldn’t follow it. 

Three reasons why I did a second round:

1. I wanted to see what a second round felt like compared to the first one.

2. I like to try things that I ask clients to try so I have personal experience and empathy for the process.

3. To be honest, I just turned 35 and I want some of those anti-aging benefits that I’m supposed to get from fasting (fingers crossed). 

So, let’s get started. 

What is the fasting mimicking diet (FMD)? 

Dr. Valter Longo - a PhD researcher at USC who has studied longevity for 30+ years - designed the fasting mimicking diet based on his (and others’) research to provide the benefits of fasting without having to completely stop eating. L-Nutra is the company he started and ProLon is the 5-day (FMD) program he designed, studied and eventually made available to the public. I provide an overview of the diet below. 

How was the fasting mimicking diet created?

Dr. Longo (per his book) created the FMD based on 5 pillars of the “Longevity Diet,” which (as far as I can tell) are the dietary principles of the FMD. This is the scientific/evidence-based foundation upon which the FMD stands:

1. Basic research and juventology, which is the study of what keeps people young.

2. Epidemiological studies, or studies focused on certain populations of people.

3. Clinical studies: Studies testing an intervention like a diet or drug to see if it’s safe and effective. This would encompass the lauded “double blind placebo-controlled trial.”

4. Centenarian studies, which are studies on people who live high quality, high functioning lives until they’re 100 years and older.

5. In his words, “the study of complex systems.” He describes this as taking an “engineering approach” to characterize how our complex human body (system) can be reduced down to a model to help understand the interactions between food, cellular function/damage, and longevity and aging.

Before I go further, I want to clarify some important groundwork. I like to visualize his work and diet like a pyramid. At the base of the pyramid are these 5 pillars. Out of his in-depth research, he was able to characterize a dietary pattern for longevity. So, atop this 5-pillar foundation are general dietary characteristics of his “longevity diet” (summarized below). Finally, at the peak of the pyramid is the carefully formulated 5-day “fasting mimicking diet” that are the specific foods of his studied “intervention.”

What are the potential benefits of fasting?

The physiological benefits of fasting include anti-aging (and even anti-cancer) activity by turning on a process in the body called “autophagy,” which triggers the body to “clean up.” In this process, our cells remove damaged contents so they can be metabolized and excreted from the body. 

Autophagy is a natural way to get pathogens and abnormal contents in cells out of the body. You can find more background on autophagy at PubMed and Healthline. Autophagy provides anti-aging benefits and potentially even some anti-cancer benefits, because when cells act abnormally and replicate in an uncontrolled manner, that’s essentially how cancer develops. Autophagy removes these abnormal or damaged cells before they get out of hand. 

So, fasting turns on autophagy and the fasting mimicking diet seeks to engage that process without having to stop eating completely. In short, you still eat food but calories are limited (800-1100 calories per day), and in theory you may still get the benefits of fasting.

Overview of the Longevity Diet Principles and the Fasting Mimicking Diet:

As I mentioned, Dr. Longo based his very specific FMD on the principles of what he calls the “Longevity Diet.” The general gist is that it’s very low protein, high complex carbohydrate, and moderate intake of high quality fats and oils. Here are the basic principles on which he bases the FMD:

• Mostly vegan/plant based: High intake of whole grains, vegetables, root vegetables, beans.

• Protein sources are mostly plant based: Beans, seeds, nuts, infrequent animal protein, fish or seafood.

• Small amounts of fish, seafood and mollusks: These are some of the most nutrient-dense foods on the planet, not to mention they contain essential omega 3 fatty acids that our bodies cannot make, so we have to eat them.

• Rarely animal protein/meat and small amounts of dairy: Mostly sheep or goat’s dairy.

• Naturally low in saturated fats because you’re eating primarily plants.

• Eat like your ancestors when possible.  

Unlike his above-described Longevity Diet, which is more of a lifelong eating style that he suggests most people adopt most of the time, the fasting mimicking diet is a very specific, calculated 5-day program (a kit of packaged food) that emulates the principles of his Longevity Diet above. You can get more details in his book, but I’ll give an overview of his 5-day FMD here:

• Day 1 (transition day): About half the food is complex carbohydrates and healthy fats (remember, low protein) in the form of packaged bars, soups and olives. You take a couple supplements (omega 3 and multivitamin). You have a few options for tea and can drink as much water as you want.

• Days 2-5 (noticeably less food): The same balance of complex carbs and fats and tea or water to drink. These 4 days you also drink a glycerol concentrate combined with water. In an interview with Dr. Longo, he explained the inclusion of glycerol was due to their discovery that glycerol is elevated in the body during fasting, and he also suspects glycerol may have to do with why the body doesn’t breakdown muscle during fasting. 

Can I create my own DIY fasting mimicking diet? 

Dr. Longo summarizes the general principles of the FMD in his book but encourages people to use his specific diet. I’m sure that’s partially because he designed his exact plan very intentionally to meet his guidelines and also because – at least in part – money, right? 

So, yes, you could make a calorie-restricted, plant based, very low protein, high quality fat diet that you follow for five days. You can actually get a free copy of his book to see what his guidelines are for this and create recipes based on that. 

Who might benefit from FMD?

First off, I want to advise that if you’re considering the FMD or any other version of fasting, you should consult with your healthcare provider(s) to ensure you’re healthy enough to do so. Ok, so Dr. Longo would likely suggest that most of us could benefit from some form of fasting and certainly the FMD. I would agree that most of us would do well to give our bodies a break through FMD or a monitored fast. 

I love that, historically, fasting has been a part of many religions and cultures. Also, humans have naturally gone through seasons of plentiful food (i.e. fall harvest) and famine (late winter). Our bodies have adapted to these seasonal variations in food intake. 

For my clients, some of the best results have come from clients who have cardiometabolic (pre-diabetic and/or cardiovascular) disease risk factors. It is also easy because the program is clear and simple; everything you need is in a box. I know Dr. Longo is working on finalizing FMDs specifically for autoimmune disease and other conditions, but those aren’t yet available. I’ll be curious to test them when they are released.

My own experience with the FMD

Read on below for a bit about my own experience with FMD, what the food is like, how I felt, and all those soups.

Fasting Mimicking: Days 1-3 

The food and drink: It’s prepackaged food, but for prepackaged food, it’s pretty good. For breakfast you eat a nut/granola-type bar, which is small but good. 

Lunch and dinners are always soups and sometimes olives and/or flax crackers. At the end of a couple days you get some kind of weird chocolate thing with inulin in it, which I called the “fart bar.” The inulin is a prebiotic (fiber), which keeps the digestive tract moving along, but bloated me something fierce.  

On days 2-5, you start drinking the proprietary glycerol concentrate with water. I put mine in the bottle they provided and added the bags of hibiscus tea to steep throughout the day. I found an interview with Dr. Longo where he says that the glycerol (which is the backbone of triglycerides - a type of fat) is elevated in people who are fasting and may be the reason that muscle is spared (very little to no muscle loss) during periodic fasting. 

Supplements: They give you an omega 3 algae supplement and a multivitamin, which were fine, although I wouldn’t have put folic acid in the multi, but that’s a blog post for another day

Energy/hunger: The first time I did this last November (2018), I felt fine, at least on days 1-4. I couldn’t believe how well I transitioned into the fast. I didn’t notice any blood sugar crashes or hangry moments. 

This second round, I had more headaches because I stopped caffeine (coffee), after day 1 because caffeine can kick you out of fasting. By days 4 and 5, I was clear headed and felt really good. 

Mindset/food obsession: The first time around, I was really busy on days 1 and 2. I saw clients all day each day and had some evening activities, so I didn’t have much time to think about it, which helped. The second time, I made more intentional effort to keep busy and check a few things off my to-do list I had been putting off. I also asked for some personal cheerleading from friends.

One other random thing: I had some really vivid dreams and slept very deeply for the first 3 nights.

Fasting Mimicking: Days 4-5

The food/drink/supplements: Same bars, soup, crackers/olives. Some of these meals are even more sparse (just soup), and I would eat like small spoonfuls to draw out the meal longer than 90 seconds. The first round, I enjoyed the food. Round 2, I couldn’t look at another spoonful of soup. Maybe the novelty wore off?

Hunger: Round 1 (last fall): I found myself talking a lot about food by this point. Upon reflection, it was interesting because I hadn’t been that obsessed with food since I was deep in my disordered eating. My husband, Rob, would tell you that I was talking about food a lot. Round 2 (last week): I was okay, but more just wanting to quit and eat real food. I didn’t feel like I was obsessing about food the way I was during round 1. 

Both rounds I was ready to quit on Day 4. I’m laughing because both times I was texting with my friend and colleague Amy who’s done FMD and had a good experience (herself and with her clients). I told her that I was going to quit and would maybe finish a day early. She encouraged me to keep going. She reminded me that the program was designed to mimic fasting and was an evidence-based approach to facilitate autophagy, which is basically the body cleaning up dead cells. She also reminded me that I’ve done other harder things in my life. So, thanks to Amy, I made it through day 5. 

Energy/temperature: The fifth and final day, I remember wearing an extra layer of clothes because I was cold during round 1 (during the fall/winter). And I cut my typical walking route with my dog short because I didn’t have the energy.

Round 2, it was a hot week in September, so I haven’t noticed temp changes as much as last fall. 

Day 6 “Refeeding” Day: They tell you to start by drinking liquids like broths and juices, which went well. Round 1: I tried some sweet potato and venison chili Rob had made a couple days before for lunch, and had a teeny bit of gurgling in my stomach, which was likely it waking up after several days. That evening I had some scallops and steamed broccoli and a glass of wine, which went straight to my head.

I was pleasantly surprised that my body adapted back to food so smoothly. I think one key is taking the morning slowly and not eating large amounts of foods or anything out of your typical norm of eating.

Round 2: I started transitioning a little bit on 5 day evening so that I would be able to eat mostly normally on Saturday. I’d say overall round 2 felt harder in some ways (sick of the food) and easier in other ways (kept myself busy and benefited from feeling clear headed and energized).

Final note: you must tolerate/like olives to do this. If you hate olives, you’ll likely be miserable because you eat them 4 out of the 5 days and sometimes twice a day!

Would I recommend the FMD?

Although I have done this two times and would likely do it again, maybe because I’m vain and want my skin to glow, and also because I want to live longer than my grandparents, I don’t think the fasting mimicking diet is for everyone. 

Some things to remember:

First, please make sure you have a healthy relationship with food if you are going to try the diet. 

Next, in terms of restrictions, this program should not be followed if you are pregnant, underweight, have low blood pressure, are generally “fragile” (Longo’s word), have diseases and/or are taking medications without first consulting with your doctor, people with diseases that inhibit their ability to make glucose (sugar) from protein, and athletes who are intensely training. 

Dr. Longo gives other warnings, but the best approach would be to work with a healthcare provider who is well-versed in the risks and benefits of the program. 

If you are already restricting caloric intake, then this may not provide the same benefits as someone who is eating a generally well-nourished, adequate caloric diet and then follows the FMD for only 5 days.

What the FMD is missing

As you can tell by its description, this is not a personalized nutrition program. If you’ve heard me speak, read my writing or followed me on instagram you know how important it is to get personalized nutrition advice. This program is a whole foods, evidence-based approach to fasting, but this boxed program is not able assess you and your individual needs. Remember, every single one of us has unique needs, not just at the biochemical or nutrient level but also from the perspective of our lifestyle, family and medical histories, emotional and mental health, cooking skill level, disease risk, metabolic health, genetics, financial health, stress, motivation, environmental and community support. The combination of all of these different needs within each individual make things a little more complex than a 5-day box of bars, packets of soup and a proprietary glycerol drink. Our nutritional needs are much more nuanced than that.

This program can never substitute for establishing a good relationship with a health care provider who can look at you, hear your story, assess your symptoms, measure your laboratory values and care about your wellbeing. As always, if you’re interested in working with me and live in the United States, you can request a discovery call. 

What have been your experiences with the FMD or what questions do you have?

Ketogenic Diet: Interview with a Keto Expert

The ketogenic diet ("keto") has gained significant popularity. I sat down with my friend and colleague, Dr. Matt Taylor, to get his take on FAQs of keto (including his research on the ketogenic diet among patients with early stage alzheimer's disease!).

I know I already wrote a blog post about why the ketogenic diet (keto) seems to be everywhere right now, but this article is going to give you tons more information from a ketogenic expert (Dr. Matthew Taylor has studied the ketogenic diet in people with Alzheimer’s disease). To catch you up on the basics of what’s going on with keto: the ketogenic diet is popular because a lot of people are finding it helpful for weight loss. In reality, it’s a new version of the Atkin’s diet, or at least the Atkin’s approach is based on the idea that our bodies will shift into burning fat when we deprive it of high amounts of carbohydrates. It’s an adaptive response our bodies have when we are faced with famine. It’s normal, natural, and generally safe… with a few asterisks, of course.

There was quite a bit of buzz around my blog post, so I wanted to follow up with some additional, in-depth background on the therapeutic use of the ketogenic diet.

So, I interviewed one of my former classmates and friend, Dr. Matt Taylor, who is a ketogenic diet expert and studied the diets (and did a keto diet intervention) among patients with Alzheimer’s disease (I’ll refer to as AD). His research used the ketogenic diet to see if it would improve cognitive symptom changes in patients with AD, and/or result in any measurable cognitive outcomes. Spoiler alert! Even though his study population was only 11 people, 10 of them had measurable improvements in their cognitive symptoms. That’s unheard of in comparison to AD medications. Typically AD meds will help with slowing the decline, but none of them actually result in improvement. Well, participants in Dr. Taylor’s study had actual improvement.

He's published a couple papers on the topic: the first found that a high glycemic (refined carbohydrate/likely processed food) diet was associated with higher burden of alzheimer's disease markers and the second study showed that putting people with mild (early) AD on a ketogenic diet was feasible. 

I sat down with Dr. Taylor a few weeks ago and picked his brain about many of the questions you have about the ketogenic diet, both related to cognitive health and AD, but I also asked him about who should and shouldn’t follow the diet.

Before I dive into the interview, a little background on the ketogenic diet. The keto diet is a very high fat (80-85% of calories), very low carb (5-10%), and moderate protein (~15%) diet. The idea behind it is that the body can shift, from burning primarily carbohydrates, into burning fat into what are called “ketones” or “ketone bodies.” Thus, the “ketogenic” diet.

Historically, the ketogenic diet has been used for epilepsy in kids when medications don’t work for them. Over time, the diet has been studied in brain cancer, and more recently there has been interest in its use for conditions involving cognition. Dr. Taylor’s study, as I already mentioned, is related to the ketogenic diet’s use in patients with Alzheimer’s Disease.

Here is my interview with Matt, condensed for readability and to avoid redundancy. I also made the more publicly relevant questions at the top and left the more science-heavy (nerdy) stuff at the bottom. Enjoy!

Leigh: So, why is keto so popular right now?

Dr. Taylor: Many researchers, physicians, practitioners, or people involved in the “keto movement” have seen improvement in weight or health conditions by following keto. Then, they encourage others to try it, and it spreads from there.

I think keto is most popular because of weight loss but I’ve also heard from many that follow the diet that they are following it because they believe it is best for their brain health. For weight loss, it’s a diet where you can eat and feel full most of the time – it consists mostly of fat, so it can be very satiating. Sometimes the diet causes people to eat fewer calories and feel satisfied. There is also evidence that some people can eat more calories and still lose weight. From a brain and focus perspective, ketones tend to give a sense of euphoria, so some people just like the way it feels and potentially feel like they have better focus.

Leigh: What are common misconceptions of the ketogenic diet?

Dr. Taylor: The biggest misconception is that this diet is a fix-all approach.

Also, there are many products touted to enhance ketosis, help with symptoms, or help with weight loss. Some of these may or may not actually work. The product consistently shown to be beneficial in this area is MCT (medium chain triglycerides). There is a lot of marketing for beta hydroxybutyrate (BHB) supplements, which research has shown that many don’t actually help raise ketones UNLESS given with MCT oil. With that said, a certain formulation of exogenous ketones has been effective at raising blood ketone levels after administration. I’ve seen posts on social media push products as “you have to be on these supplements follow the ketogenic diet properly” which is not true, some of it is gimmick.

Leigh: So what’s being portrayed in media that IS or ISN’T accurate?

Dr. Taylor: Once again, just the misconception that the keto diet is a panacea. Keeping focused on research, I try to stay away from what media is pushing out, but I do see what’s being marketed on social media. I’ve been asked to talk at conferences and seminars that companies have put on, but I haven’t taken those gigs, so can’t say for certain.

It’s funny, I know several people who research the keto diet that are surprised to learn how many people are following it. Listening to people who are actually DOING it and articulate some of the benefits and obstacles can be helpful for scientific messaging. Sometimes there is good info in the keto communities, but not always.

Side note: here’s my (Leigh’s) previous post about keto that explains more.

Leigh: Who would benefit from following keto?

Dr. Taylor: We use the ketogenic diet very successfully in childhood epilepsy. Evidence has shown potential for people with adulthood epilepsy, Alzheimer’s disease and other neurological conditions, Diabetes, and even Polycystic Ovarian Syndrome (PCOS). There is emerging evidence around people with malignant tumors (specifically Glioblastoma – brain cancer) on keto with a potential shrinking effect and improvement in symptomatology. Individuals who have those types of conditions may benefit from keto. The ketone metabolism research shows us that many of these conditions are metabolic in nature, which we haven’t always known. Where we’re seeing an effect of the ketogenic diet is on conditions driven by metabolic changes impairing our body’s ability to use glucose for fuel. Once that condition has occurred, it doesn’t matter how much sugar you provide, there it seems there is a preference for ketones instead of glucose for fuel. Even in situations when glucose isn’t as usable anymore, such as in Alzheimer’s, ketone metabolism stays intact. Traumatic Brain Injury (TBI) is another condition that I’m researching with the keto diet. 

Leigh: Ok so this sounds like it has potential for a lot of different situations right?

Dr. Taylor: In science, we’re conservative about using approaches that are this extreme because we’re concerned about any possible negative outcomes. It’s interesting, many people have started this diet for many different conditions, and so we’re sort of letting the population do tests on themselves. Healthcare professionals can see the results from an anecdotal standpoint and we can then use this as rationale for future studies.

Leigh: Who shouldn’t follow keto?

Dr. Taylor: First, people with carnitine deficiency should not follow keto (you would have discovered/been diagnosed with this in childhood if this were an issue for you). This deficiency means that it’s harder to get fat into the cell for fuel, and you no longer are providing glucose as fuel either, so this could be a problem. There is some evidence that supplementing with carnitine may be helpful. Really, it comes down to personalizing the diet, because there are different ways to do keto, and it’s not for everyone.

Secondly, people with an APOE4 mutation may want to stay away from keto diet. These people don’t seem as able to handle high amounts of fat, especially saturated fat. This can be tested via genetic testing. It’s suggested that following the keto diet can have adverse cardiovascular effects like increase cholesterol levels and many with the ApoE4 gene don’t seem to have the same cognitive response in research studies.

If you’ve given it a try, consider how you feel. There is an adaptation phase to diet that many people experience, often called “Keto Flu”. The symptoms while adapting vary by individual, I’ve seen people go on the diet and feel great immediately, and other people go a handful of days and feel kind of bad, and others that feel horrible. For many, they adapt and feel good after a few days. Some never adapt at all and never feel good, once again it’s about individualizing the diet for each person. There is some really interesting evidence that feeling this way mostly comes down to low sodium intake to replete the high amount of sodium excreted by following the diet. I recently saw data from a study that put several hundred people on the diet. By ensuring that those individuals consumed plenty of sodium, they were able to attenuate many of the side effects associated with “keto flu.”

Another individual component to consider is insulin level before starting Keto. People with higher insulin levels may take longer to shift into ketosis and possibly feel bad. Also, what is your nutrient status coming in? Many people already lack electrolytes and hydration and this diet requires more hydration. Burning more fat makes you excrete more fluid, so people who aren’t hydrating or replenishing electrolytes will likely feel awful. The diet isn’t for everyone, if you follow this diet and feel awful on it (and continue to feel awful) more personalization may be necessary, or it just may not be right for you.

Side note: people with history of (or current) eating disorder should definitely consult with their healthcare provider and eating disorder recovery/healthcare team before taking on any dietary changes or restrictions.  

Leigh: On a basic level, can we get people to follow keto long term? Should that be the goal? Can we see changes, metabolically, with just macronutrient changes (without focusing on fruits and veggies)?

Dr. Taylor: After the study of metabolic change builds more evidence, then we can ask that more complex questions. We see overall improvement in condition, but what we also want to consider personal experience? I think diet quality could play a part, but that hasn’t been studied yet.

Leigh: What would you tell someone who is thinking about starting keto?

Dr. Taylor: Seek out advice from someone with experience or background in this area, like a Registered Dietitian Nutritionist (RDN). You may run into RDNs who are hesitant to comment or advise on this diet if they don’t have experience with it. However, those with experience would be more apt to provide objective help.

Leigh: What’s one thing you would tell someone to expect?

Dr. Taylor: First, following a ketogenic diet is usually a big change from most people’s typical way of eating. It’s really counterintuitive for many to eat as much fat as is required to follow the ketogenic diet and carbohydrate restriction can be difficult for people who have carbohydrate food cravings. It’s also possible that you may feel crummy for a period of time while your body adjusts to a different type of fuel (shifting from carb-burning to fat-burning).

Leigh: How does one know if they’re just adapting to fat-fueling or that the ketogenic diet isn’t working for him/her?

Dr. Taylor: It could be either, but there are steps you can take in preparation for starting keto that can help you to know if it’s a feasible option before getting fully invested. It could be helpful to know your APOE status, personally I’m a proponent of genetic testing, but I realize that some people are hesitant to that for various reasons. It may be helpful to do blood work from a PCP or other physician who could look at APOE status because we’ve seen people with APOE4 who don’t respond as positively as others. If you don’t know your APOE status and go on this diet, it’s advisable to get your cholesterol checked periodically to make sure you aren’t doing more damage than good.

Another helpful tip is to be proactive with hydration and electrolytes like potassium, phosphorus, and sodium. Bone broth has been helpful for adaptation phase, patients have been using bone broth to feel better and it is becoming more widely available.  In my research, we provided participants a multivitamin and a potassium/phosphorus supplement. My current study in patients with traumatic brain injury (TBI) with a small sample size provides a multivitamin but not phosphorus/vitamin D. I’ve never used exogenous ketone supplements in my research.

Leigh: Is it bad to abrupty start or stop following a ketogenic diet?

No! Actually, with the research we’ve had some interesting findings. The researchers determine “compliance” as following keto about 70-80% of the time. This means that ¼ – ⅓ of the time not following keto, which is a way of cycling, whether it happens intentionally or organically. This indicates cycling or abrupt stopping would be ok. People who have stopped the diet can pick it back up and resume. Once you’ve started making ketones, there’s an idea (among keto experts) that ketone adaptation, where you switch over to ketone fuel metabolism, becomes easier. There isn’t really a concern unless you’re just generally yo-yo’ing (dieting) bouncing back and forth between ketogenic and Standard American Diet (SAD), which is not healthful. This is a lifestyle/behavior change that is so important, and moderation is also important. Extreme shifts may be problematic, but we don’t know because we don’t have the evidence. Variation is important, cycling with a plan is probably a good approach, but we still need evidence on this as well. All these assumptions are also focused on diet quality. If the shift is on keto I eat bacon, eggs, vegetable oil, cheese (not high quality) then shift to bacon, eggs, oil, cheese + carbs, this is a problem no matter what because in both cases the fats are unhealthy.

Another interesting area of research is in athletes and performance. If you wanted to look into it more, Jeff Volek has discussed the concept of cyclic ketosis, which is the idea that if you’re keto-adapted you can be a more efficient athlete because you’re good at using 2 different fuels whenever they’re available.

Leigh:  Are there actual benefits to being in ketosis or burning ketones?

Dr. Taylor: Ketones are not only providing energy but are also powerful messengers that are important for metabolism. A bunch of animal studies have also shown that ketones are anti-inflammatory. Inflammation is necessary for healing an acute injury, but long-term chronic inflammation is linked to chronic disease. So, ketones have been shown to suppress pro-inflammatory pathways over a long period of time.

Leigh: Tell me about your study/work for your dissertation or any of your other keto-related research? Summarize your findings (high level) any surprises? conclusions?

Dr. Taylor: My original exposure to this was a pilot research study with Alzheimer’s disease. One of the key findings in Alzheimer’s patients is that their brains refuse to use glucose as an energy source, so we’ve started to shift our thinking of AD as more of an energy crisis. Amyloid and tau proteins are involved, but it’s more that brain metabolism has changed. Most basic thought behind research was to provide the brain with alternative fuel source. One study he did put Alzheimer’s patients on keto for 3 months, there were 15 participants at the start and 10 of them completed the study. Of those 10, 8 of the patients had improvement in cognition and decreases in Alzheimer’s symptoms. One person worsened, but he had other variables with his health, so it’s difficult to know what was going on, or if it was related to the diet change. With our study, the ketogenic diet education focused a lot on diet quality. Actually, I’m currently writing a paper regarding the positive changes in nutrient density of this study’s ketogenic diet vs. the standard diet that participants were following. I’m convinced that this type of keto diet is very different from a diet that only focuses on macronutrient ratios.

I remember from the research, a story about a patient that would read the newspaper multiple times a day but wouldn’t retain any of that information. About 2 months into the diet/study, the study partner reported that the patient had started reading the paper only once per day and retained some of that information later in the day. This type of story gives me optimism that it might be helpful for Alzheimer’s patients.

Leigh: What surprised you from your studies?

Dr. Taylor:  I was surprised that older adults would follow it! To be honest, it was a challenge because these people have grown up through a low fat marketing era, and people are hesitant to increase fats to the level they needed on the study. Throughout, I had several shifts in perception. I had gone into it thinking it wouldn’t be too big of a challenge, but as I got feedback I realized how ingrained the low fat messaging was for these people. Also, I had no anticipation for the type of cognitive results that we saw. We saw improvements in patients that really compete with, or surpass some of the most successful Alzheimer’s research in the past. In Alzheimer’s research, a drug is considered to be successful if cognition decline is slowed, whereas in this study there was actually cognition improvement.

Leigh: What about the ketogenic diet for non-brain cancers such as Prostate and bladder cancers?

Dr. Taylor: There is some real interest in using it in these conditions, but there is currently not enough research to draw a conclusion. Based on results of other research it wouldn’t surprise me if it might help.

Leigh: Weight loss?

Dr. Taylor: Keto is one of the ways to do it. From experience of putting individuals on the diet, people have been able to eat a higher caloric amount and still lose weight. It has a thermogenic effect in that it boosts fat metabolism, which makes it effective for losing weight. After weight loss, like most other diets, you can’t go back to eating haphazardly because you’ll regain the weight. Surprisingly, it takes a lot of work for our bodies to store the fat that we eat as fat. Eating fat does not make you fat. (mic drop)

Leigh: So, would people with diabetes benefit?

Dr. Taylor: There is evidence that supports the use of keto in diabetes. Ketones are safe; it’s ketoacidosis that is dangerous.

Leigh: How can one be safe as a diabetic on a ketogenic diet?

Dr. Taylor: First, we should talk about the difference between type 1 and type 2 diabetes. Briefly, type 1 diabetes is an autoimmune disorder where the beta cells (cells that make insulin) in the pancreas have significant impairment or completely stop making insulin in response to sugar in the blood. Type 2 diabetes is when the cells of the body become resistant to insulin, meaning that the pancreas must produce much more insulin in response rises in blood sugar in order to transport it into the cell.

There is a very serious condition that can occur in uncontrolled type 1 diabetics known as ketoacidosis. Because of this condition, ketones are commonly thought of as bad or dangerous, but there is a big difference between ketosis and ketoacidosis. As we’ve discussed, our cells can burn either glucose (sugar/carbohydrates) or fat (in the form of ketones) for energy. Ketoacidosis is dangerous in uncontrolled type 1 diabetes in which blood levels of both glucose AND ketones are well above normal. This is a dangerous, potentially lethal, combination as high levels of glucose and ketones overwhelm the body’s ability to keep pH levels in a normal range. Ketoacidosis in type 1 diabetes is induced by the following:

1. Ingestion of carbohydrates elevates blood glucose (sugar) levels.
2. The pancreas does not produce insulin to drive the glucose into the cells, causing the body to think it is in a starved state.
3. To compensate for the body’s perceived starved state, fatty acids are converted to ketones to use as an energy source.
4. Because glucose is high and ketones are also being produced, the signal to shut down ketone production is severely impaired, resulting in extremely high production of ketones (~20+ mmol/L) and an overly acidic blood environment.

On the other hand, ketosis from following a ketogenic diet (without having type 1 diabetes) involves an elevation of ketones from what is normally ~0.1 mmol/L to anywhere between 0.3 to 1.5 mmol/L in the blood. The ketogenic diet provides a substrate that our cells can use and doesn’t result in the perceived energy crisis seen in DKA. Because ingestion of carbohydrates is low, glucose levels remain mostly normal while the brain and other tissue happily use the ketone bodies for energy. Ketones are more acidic than glucose, but that is okay at these levels since we are generally good at buffering the blood to normal pH levels.

It appears that the ketogenic diet may be safe and helpful in both type 1 and type 2 diabetes. First, a case study published a few years ago reported successfully treating type 1 diabetes in a 19-year-old male (Tóth & Clemens. Int J Case Rep Images. 2014). The patient previously utilized an insulin injection regimen and short-acting insulin for sporadic high glucose. Through 6.5 months on a vegetable-rich ketogenic diet, this participant maintained very tight glucose control and was able to incrementally reduce insulin usage until he came off of his insulin injections. (that’s insane, and unheard of) There were no adverse events reported. Interestingly, he also improved C-peptide production, which suggests that his pancreas regained some ability to naturally produce insulin. Similar findings have recently been published in a cohort of 11 type 1 diabetes patients (Leow. Diabetic Medicine. 2018). Disclaimer: This was all under STRICT supervision by a medical team. It is very important for an insulin-dependent diabetic to follow the recommended carbohydrate intake for their insulin dosage. Changes in eating patterns can affect insulin needs; therefore, making dietary changes like this must be done with a medical professional.

There was also this really cool study published by Stephen Phinney and Jeff Volek this year (Hallberg. Diabetes Therapy. 2018). Out of 349 type 2 diabetes patients, 262 patients were treated via a continuous care model that included a vegetable-rich ketogenic diet and 87 received usual care for type 2 diabetes. The patients on the ketogenic diet produced a blood ketone range of 0.5-3.0 mmol/L, demonstrated better diabetic control, and had significant reduction in diabetes medications when compared to the usual care group. The overall care model was labor intensive for the practitioners and researchers, but this study showed some pretty cool results for potential use of the ketogenic diet in diabetes treatment. They also, really focused on diet quality, which makes me think that there is long-term feasibility for the style of diet that the patients followed.

Leigh: So if someone is concerned about ketoacidosis, is it important to monitor ketosis and shift more slowly? 

Dr. Taylor: I can’t say that I’m currently a proponent for keto in type 1 diabetes as I feel there much more need for research, but the ketogenic diet itself should not induce ketoacidosis. However, if people with insulin-dependent diabetes did want to pursue this as a potential treatment, it would be imperative that they do so through a medical professional with significant knowledge in the area. Following a ketogenic diet will require adjustments in insulin dosage and strict adherence to the diet protocol.

There’s a line of thinking that if you’ve become unable to use glucose (sugar) as a fuel, which is what diabetes IS, then the ketogenic diet may be an alternative. Think of it like this: why give your body more fuel that you can’t use? In type 1, perhaps keto could serve as a therapy that would alleviate the need for insulin injections. In type 2, it seems that it is effective in bringing abnormally high insulin levels down due to decrease in need. 

Leigh: Does the ketogenic diet contradict the idea that a calorie is a calorie?

Dr. Taylor: On keto, the machinery used for getting glucose metabolism are reduced because you start using more of the fat and ketone metabolism machinery. Therefore, everything that we know about metabolism when we are primarily using glucose is turned on its head. One of the effects of the diet could be that we increase the number of mitochondria available, which is where the body makes energy.

Leigh: Is there a thermogenic effect?

Dr. Taylor: Ingesting more fat for energy makes you more likely to burn more of your stored fat as energy. Think of it this way: fat burning machinery is at its peak, so stored fat in our bodies become available as an energy source.

Leigh: Why do ketones make us make more mitochondria?

We still aren’t exactly sure why. Some theories include that ketogenic diets cause less metabolic stress allowing for more mitochondrial biogenesis or perhaps that ketones themselves have a signaling effect. It’s very important to keep in mind that all of the research available has been done in humans/animals with health conditions, not those that are generally healthy.

Leigh: Is there any evidence about the quality of the diet and efficacy of keto or is it all about the macronutrient balance?

Dr. Taylor: Right now, research outcomes have all been about macronutrient balance. I’d really like to see research go toward diet quality, which is coming. From a clinical standpoint (non-research), I’ve observed it is more feasible when people focus on quality, especially when following long term. A keto diet based on high quality foods would include beneficial fats, vegetables, and generally more of a whole food approach. These people seem to tolerate the diet better. They likely could go long term and have success, but we still need to learn if it’s feasible to follow a strictly ketogenic diet long term.

Leigh: Is there any effect on the gut while doing keto?

Dr. Taylor: Interesting new research about gut flora modulation suggests that some benefits of the ketogenic diet may be mediated/modulated by gut flora changes.

Leigh: What are the changes in flora?

Dr. Taylor: I’m not sure how it may affect people with an “optimal flora” but if you take, for example, epilepsy, MS, etc. it is suggested that the gut flora may be altered. In epilepsy, those changes in gut flora have associations with changes in seizure control. There are some animal studies where changing the gut flora can help halt seizures. This poses an interesting question: does diet quality in the ketogenic diet matter? Now we have to ask: do the microbes change by the macronutrient distribution, or does the food type matter (e.g. do veggies/fruit matter)?

What’s the Magic Health Pill?

My take on What the Health and The Magic Pill, two popular food and health documentaries

Over the past year, I’ve had people from all seasons of my life reach out to me and ask me what the H I think about the “What the Health” and “The Magic Pill” documentaries.

I have to be honest… I hadn’t even watched them. Although I’m obviously pretty interested in nutrition, health, and what we can do to reverse chronic disease, I sometimes need to just watch a binge-worthy documentary on Netflix (um… Wild Wild Country and Evil Genius anyone?!). I just need to shut off from all of that. Plus, I get to the point where I only need to watch 5 minutes of a documentary, see which “experts” they’ve interviewed, and I can already predict the bent to the show.

So, I finally bit the bullet. 

I picked these 2 out because they’re 2 of the most popular/high impact (people are making big health/diet decisions based on watching these), and they were both published in 2017. Other food and health-related documentaries I could have talked about include Fat Sick and Nearly Dead, Food Inc, Fed Up, Forks Over Knives, Cowspiracy, King Corn, That Sugar Film, and honestly more than I realized existed before watching each of these.

I had an intern working with me the past couple weeks, and we sat down to watch them (lucky her, right? Your assignment is to relax on my couch and watch movies with me). Together, we put this table (below) to compare and contrast the two documentaries. If you’re unlikely to read through the table, let me summarize it briefly here for you:

Ok, first before I go any further, I want to acknowledge that this is a very high level summary of what I see as the main themes, similarities and differences between the two documentaries. This is by no means comprehensive, and there is definite nuance to each.

So, now that we have that out of the way, here we go:

What the Health summary

What the Health (WTH) claims that a vegan, plant-based diet is the best health approach to eating. You should eat zero animal foods, and any chronic disease that comes from poor eating comes from foods derived from an animal. Sugar doesn’t matter. Eat all you want. You can see in the table that WTH is most concerned about processed animal products without concern for processed or refined carbohydrates. WTH would say that there is also no difference between organic or conventionally-raised foods.

The Magic Pill summary

The Magic Pill (TMP) claims that an ancestral “paleo” or ketogenic-type diet is the most healthful. Get back to the way we’ve historically eaten and let our genes lead the way. TMP would care more about highly processed/refined foods, overall. Quality of food is the higher priority over whether foods are animal or plant-derived.

Both documentaries hold big ag and big industry (pharmaceuticals and food) responsible for the cultural drive for this way of eating. They also both emphasize minimizing highly refined or processed foods (whether meat or carb). They both tell compelling stories of individuals who have dramatically changed their diet to follow the purported “best” way to eat, and you watch these people share how the diets have transformed their lives, leading to lower pain, less medication, and an overall better quality of life. Both documentaries tell compelling stories, and that’s what we all love. I can see why people choose to change their diets after watching either!

My take away: each of them emphasizes the importance of plant foods. Although they don’t address it in either movie we need to be mindful of the idea that you can eat a “healthy” version of either of these “diets,” and you can eat a less-healthy version (soda & chips are vegan and bacon & cheese are keto). So, using some common sense with their application is always important.

Is there a magic health pill?

So, What is the Magic Health Pill? I'm sure you can guess what I'll say, but there's no short cut to wellness. Eating more plants and less processed foods is always going to be a good way to approach your diet. The evidence is consistent in the literature that eating more plant foods is associated with better health outcomes. So, if you've never eaten your veggies, it's never too late to start.

I would say that if you’re unsure of what to do, just take a look at what you’re eating on a weekly basis (maybe keep a weekly log), and also pay close attention to how you're feeling. Do you have good energy, focus, good digestion? If not, your lifestyle may be playing a role in how you're feeling. As far as how you're eating, if half or more of what you eat is coming out of packages or windows (drive-thrus), then maybe a change would be worth it? If you’re eating mostly whole, minimally processed/refined foods, then you likely have a solid foundation. My only word of caution for the dietary approaches from each documentary is that they can both leave us vulnerable (similar to a Standard American Diet) to nutritional deficiencies if left unmonitored over a long period of time. There's no "one size fits all" approach to lifestyle changes, especially when it comes to diet. Integrative and functional healthcare practitioners are best equipped for monitoring and evaluating your nutritional status and would be a great sounding board for your efforts.

I know a really good nutritionist, if you’re looking for one.

So, what did you think about the documentaries? Have you made any changes since watching either or both of them?

View fullsize

Why Keto is Everywhere Right Now

By Leigh Wagner, PhD, MS, RDN

If you follow my Instagram, you know that I took a poll to decide whether I should blog about the ketogenic diet or the documentary “What the Health.” And, keto won, if only slightly. So, my hope is to give a really high level overview about keto with a few zoom-ins (without writing an entire referenced review article - but there are some references). I’m also hoping this will help you look good at dinner parties when someone’s diet endeavors inevitably come up.

So, here we go.

What are the potential benefits of keto?

As with most diets or “lifestyle changes” (as we love to call them in the biz 😜), diets often run in cycles, come and go. We have low fat, low carb, high protein, and every other nuanced permutation of different macronutrient (carb/fat/protein) amounts.

What’s different about the ketogenic diet, is that there’s some compelling evidence suggesting that it may be super helpful for some people with certain diseases (some, but not all, cancers, Alzheimer’s, and the OG therapeutic keto condition: epilepsy).

With that being said, one reason keto is becoming increasingly popular recently is because it can also help facilitate weight loss. And because of that simple reason, you can't escape it. Keto is everywhere right now. 

What is the ketogenic diet?

But before I get into that (and why), let me explain what the ketogenic diet, or “keto,” is.

The ketogenic diet is a diet that’s very high in fat (like 80% of your daily calories are fat), very low carb (like 5%) with moderate-to-low protein (like 15%). The idea (and reason it’s called “ketogenic”) is because the body, when restricted nearly completely of carbs, will shift into burning an alternative energy source called “ketones.” It’s like a flex fuel car.

What do ketones do?

So, ketones, which are sometimes called “ketone bodies,” are just tiny parts of fats that are broken down differently than normal (into 2 carbon molecules), and instead, they’re broken down into 3 carbon compounds called “ketones.”

INTERESTINGLY, (for a nutrition nerd), ketones can be burned by the body and the BRAIN - even though I was told in conventional nutrition school that our brains only run on glucose). The body is able to burn fats more easily that we have in reserve. Think stored fats… like in our bellies, butts, and thighs. I like to call this “fat burning mode.” So, our bodies can use this alternative metabolic process of ketone production and we don’t have to use sugar or carbohydrates to function.

Keto and the Atkins diet

So, the reason I brought up the idea of diets coming in and out of style is because, remember the Atkins diet? Atkins is basically a ketogenic diet.

To give you an analogy, Kleenex® is a brand of tissue, while Atkins® is essentially a brand of ketogenic diet. Does that make sense? And, apparently, (one of my clients told me), the original Atkins diet even instructed you to buy ketone strips (urine testing strips to measure if you’re making/burning ketones).

So, the “keto” diet in popular culture is really just the Atkins diet coming back as a new trend. Although, I would say that when I use the ketogenic diet therapeutically, I encourage clients to focus on high quality fats and oils (coconut oil, extra virgin olive oil, organic pasture butter, avocado oil, nuts and seeds) whereas I always remember people on the Atkins diet just eating cheese and bacon. Although, now as I'm looking around on social media at "keto" posts, it's confirming that there's a lot of bacon and cheese (palm to forehead).

Side note for the people who have diabetes or have family members who do: Don’t freak out on me too soon, you’re probably thinking about diabetic ketoacidosis.

Metabolic ketosis is NOT the same as diabetic ketoacidosis. Diabetic ketoacidosis is a very serious, dangerous problem and will lead to severe symptoms. Please work with your physician or integrative dietitian 😉 before you make any dietary changes.

The ketogenic diet and weight loss

So, here’s the deal with the weight loss stuff. With other “diets” (like low-fat or long-term low calorie diets), the body will adapt and lower its metabolic rate. On the other hand, with a very high fat, low-carb diet like keto, the body will maintain its metabolic rate (and lean body mass) and still allow weight loss.

From a 2018 article in the Journal of the American Medical Association (JAMA):

“… There are hints that the ketogenic diet may be different [than other diets]. A meta analysis of 13 randomized controlled trials suggested that people on ketogenic diets tend to lose more weight and keep more of it off than people on low-fat diets. People placed on these diets often report decreased hunger.”

But, before you go jumping on the keto bandwagon (really, I don’t encourage everyone to do this), remind yourself of how surprised you were that this diet is 5% carb and 85% fat. I’m not saying you should be scared of a high-fat diet (I eat a ton of it!), but I am saying that eating a really high fat, low carb diet in America in 2018 could be challenging to implement long term in your life, as a sustainable approach.

Instead, what’s most likely beneficial is that you not eat the same food all the time. Just like I told you that long-term calorie restriction can lower your metabolic rate (meaning our bodies burn fewer calories by adapting to protect itself from this contrived famine we’ve put ourselves on), if you eat more of a variety of calories, variety of macronutrients, variety of foods, at various times of day, and in various amounts… that’s probably even better for us.

If you’re a fitness junkie, you can think of this as “cross training” or always keeping your body guessing and not adapting to your 5-mile run you do every day. The body will adapt and may not benefit as much from the exercise – you always need to “switch it up.” 

As always, whole foods are best

As with any diet, you can follow a whole foods-based version of it (lots of plants, healthy fats and oils, and good quality protein) or you can follow a less healthy version. Vegans can eat potato chips and drink Coke and paleo dieters can eat bacon and cheese all day. That doesn’t make these diets healthy. I think you get the picture.

So, keto can absolutely be a helpful for certain people with guidance from someone skilled in using the diet therapeutically. I've seen it transform lives. There are tons of resources out there, but always keep in mind that often people are promoting what works for THEM and don’t get too tied up in that – you need to do what works for YOU.

So now that you have the basics of keto, have fun at your dinner party! And if you want more info on the keto diet, read my interview with a ketogenic diet expert.