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In 2012, when I began writing this blog, the paleosphere was what I am now thinking of as  “old school paleo.”

Paleo bloggers then focused on leanness, fitness, biohacking, and generally being a hard guy (taking baths in ice water was a thing). We were told to never eat legumes or other carbohydrates. We were told that it was better to starve than to have a meal that wasn’t paleo. We were admonished to never snack. We were told that fasting was a lifesaver, and ketosis, a miracle.

But in the years since 2012, in small part due to my own advocacy and in large part due to the wisening up of the whole sphere, paleo leaders opened their eyes to the larger picture. They realized that women’s bodies might need some more calorie nourishment than men’s. They realized that carbohydrates can sometimes be helpful – and eventually appeared to embrace them entirely. They realized that fitness is different for everybody, and maybe some people should do less of it. They recognized that body fat percentage doesn’t dictate the quality of someone’s health. Major parts of the paleosphere relaxed into an atmosphere of love and encouragement and relaxation.

All of this means that I was very surprised rounding the corner  into 2017 when all of the sudden everybody was talking about fasting  and ketosis again. I will write about fasting in another post. Today, I will focus on the return to ketosis. I will talk about what’s bringing it back, and then re-examine what this can mean for your body and your mental health.

What is ketosis?

I am going to steer clear of giving you a long, technical definition of ketosis. I do however think it’s worth learning the biochemistry if you plan to experiment. In that case, I highly recommend Dr Peter Attia’s posts or Dr Chris Masterjohn’s.

In short, ketosis is a state the body enters when there is an excess of molecules called acetyl groups over oxaloacetate. This happens when there is a shortage of glucose supplied to the metabolic processes that create energy–ie, when you eat a very low carbohydrate diet. Yet interestingly enough the body will also produce ketones when medium-chain fatty acids enter the metabolic processes. Most people do not know this, but it’s very important, and I will return to it later.

So then, when there is this excess of acetyl groups relative to oxaloacetate, the body produces something called ketone bodies. Ketone bodies come from fatty acids that the body has liberated from fat tissue, which can be used as an alternative fuel to carbohydrates. This is important because the body (and specifically the brain and heart) literally need carbohydrates or ketone bodies in order to function. When carbs are gone, basically, ketone bodies step in to do their work.

People typically achieve ketosis by fasting or by eating diets very low in carbohydrate (high fat, moderate protein). This calls for at least fewer than 50, and maybe more like 20, grams of carbohydrate a day. This depends on your age, body type, activity level and the like.

You can verify how deeply your body has gone into ketosis by peeing on a stick, which reveals the level of ketone bodies being circulated in and used by your body.

Why do people do ketosis?

The supposed health gains of ketosis are different depending on who you ask. Some will call is a miracle that cures all ailments, some will be more circumspect.

In general, there are two many categories of benefits that people talk about: metabolic health and weight loss, and performance gains. There is some truth to each of these categories.

For metabolic health and weight loss, ketosis can be helpful for people who struggle with insulin resistance. Now, to be clear, ketosis does not cure the underlying problems that cause insulin resistance such as poor gut health and inflammation. 

But ketosis can provide a way to circumvent the issue. If insulin levels are chronically high and you eat a moderate carbohydrate diet, you may find that you never lose weight, because the body always has a surplus of sugar to burn instead of dipping into its fat stores, which it really only does once the body’s glucose and glycogen stores have been burned through. If however you keep your body’s carbohydrate intake to an absolute minimum, it will more consistently be able to reach into fat stores to burn fat (and make ketones to burn), given that there is a caloric deficit. This is something everybody, and especially ketosis aficionados, should keep in mind; calorie deficits need to be present in order to lose weight.

This being said, there is debate about whether or not there is a “metabolic advantage” to being in a state of ketosis. It is possible that, given how much energy it takes to create ketone bodies, the body actually burns slightly more calories in ketosis than otherwise. Unfortunately this matter is not altogether settled. Though it is worth noting that even if this is the case, the difference is relatively small. For the most thorough discussion I’ve seen of this issue in a blog, see Dr Attia’s write up here.

Ketosis may provide metabolic benefits. They include: 

-Regulation of blood sugar levels for people who are sensitive to blood sugar swings (as the body produces its own blood sugar in a state of ketosis so there are fewer fluctuations)

-A reduction in circulating insulin levels for those who were previously insulin resistant; an increase in insulin sensitivity

-Potential weight loss due to increased insulin sensitivity and ability to burn fat

-Potential weight loss due to decreased caloric intake from eliminating an entire food group

The other main category of improvements people discuss have to do with performance. Many people say they think more clearly or have more mental or physical energy while on ketosis. This does not seem an altogether unreasonable claim since the brain burns ketones efficiently, and ketosis can help keep blood sugar levels stable.

Importantly, however, I would like to draw attention to the fact that the adrenal glands can get involved in ketosis – as they play a role in regulating blood sugar, among many other things. When the adrenal glands are active, typically cortisol, adrenaline, or norepinephrine (or any myriad of other stimulatory chemicals) are released into the bloodstream. Norepinephrine, notably, is released in a state of fasting at 2x the rate of regular body metabolism. This can create great feelings of energy. And it can help preserve muscle mass. But it is important to note that it can also lead to disruptions to circadian rhythm, or a feeling of being over-wired.

Specific Health Conditions

Finally, there are also specific health conditions for which ketosis appears to be therapeutic. Certain neurological- and degenerative diseases such as Alzheimer’s, dementia or Parkinson’s may be helped by ketosis, as may seizures and chronic migraines. Ketosis can also starve tumors which thrive on glucose as a fuel source, and therefore be helpful for cancer, specifically that of the brain or blood.

Importantly – we should be clear about which types of benefits we are chasing

So you may decide that ketosis seems like a good idea, something worth trying. But it is important to note something that often goes neglected in conversations about ketosis: there is more than one way to achieve the presence of ketone bodies in the blood. In fact, there are two main ways, and they correlate to the two different types of benefits discussed above: the metabolic, and the performative.

The traditional way of achieving ketosis is to eat a low carbohydrate diet. This has two types of benefits: 1) it can increase insulin sensitivity and can therefore help remediate insulin insensitivity and diabetes. It can also help stabilize blood sugar, and, importantly, if one is eating fewer caloriess since one’s diet is almost 100% fat, then one will be in a  calorie deficit and may lose weight. 2) Ketosis can increase mental performance given that ketone bodies are produced as a result of carbohydrate restriction.

But there is another way to achieve ketosis. You can get ketone bodies into your bloodstream simply by consuming MCT oil. Chris Masterjohn addresses this masterfully in this podcast (linked to transcript). I stated earlier in this post that ketosis is widely misunderstood as a result of low carb dieting. While low carb dieting does lead to the acetyl group excess over oxaloacetate in the fuel burning process that leads to ketosis, so do medium chain fatty acids. So if you cook with or add MCT oil to your diet (coconut oil contains MCT’s but is far from 100% MCT, so if you’re looking for a ketosis effect it may be wise to purchase an MCT oil such as this one), you can achieve the performance-enhancing effects of having ketone bodies in your bloodstream without subjecting your body to the rigors of a low carbohydrate diet.

Exogenous ketones

You can also get ketone bodies into your bloodstream by consuming exogenous ketones. This is a fancy way of saying “eating ketones.”

In fact, exogenous ketones are I think a big part of why ketosis has made a come back in recent months. There has been an explosion in the market for selling ketone bodies, especially with MLM schemes. I can’t tell you how many facebook posts I see from paleo friends talking about how great their exogenous ketone supplements are. I am sure they really are. But it is also a part of an industry wide boom, so I’d step very carefully about choosing a brand and making sure you know what you’re buying into.

Importantly, if you take exogenous ketones, a) know that you are taking exogenous calories as ketones are calories, and b) know that you will be getting the performance enhancing effects of ketosis but not the insulin sensitizing effects of a very low carbohydrate diet. I do not caution you because I think this is a bad thing. In fact, this is a great option for many people, as I do not think the low-carb aspects of ketosis are important to strive for unless it is an experiment you choose to conduct for the sake of managing diabetes or etc.

How to achieve ketosis performance gains without sacrificing metabolic health

I talked at length before about how low carb ketosis poses potential metabolic gains. This is especially true for people who suffer from diabetes or insulin resistance and/or also have high body fat percentages.

But I would be remiss if I did not also point out – especially as Paleo for Women – the many different groups of people who may be hurt by ketosis.

Women of reproductive age who are attempting to conceive or are pregnant should probably not undergo low-carb ketosis, as carbohydrates play an important role in A) pregnancy, and B) assuring the hypothalamus that the body has been properly fed. In fact, insulin is actually an important satiation hormone. For women who want to conceive, it may be best to err on the side of caution and make sure you get bountiful carbs.

Women with sensitive reproductive systems may want to step carefully. If you have a history of low hormone levels, hypothalamic amenorrhea, dieting, or irregular menstrual cycles, the hormone changes invovled in low carb ketosis as well as the uptick in stress hormone levels may hinder your reproductive hormone production.

People (mostly women) with sensitive thyroid systems may also be in jeopardy from low carb ketosis. Ketosis is well known to downregulate thyroid production. T3 (the form of thyroid hormone that is actually active in cells) decreases, and reverse T3, a molecule that blocks the activity of T3, increases. Ketosis advocates may bend over backwards trying to make this phenomenon seem hunky dory, but I would advise anyone with thyroid issues to step carefully around ketosis. If you have clinical hypothyroidism I would consider consulting a doctor first.

People with adrenal issues or a lot of stress. Adrenal glands may become more active with low carb ketosis, which can exacerbate  feelings of being wired, stress, and all the attending symptoms that come along with it.

People (especially women) with sleep issues. Low carb ketosis may up-regulate the production of stress hormones, which can have a negative impact on sleep.

In general, low carb ketosis is another stress on the body. For people who can handle that stress – it may go off without a hitch. But  if your body is predisposed to adrenal, thyroid, or hormone issues, you may wish to at least step carefully.

What about my psychological health?

I will be publishing a post on the concept of “ketosis freedom” next week. In the meantime, it stands to note that this is obviously a highly restrictive diet. If you have a history of punishing yourself for falling off the wagon, feeling guilty about food, engaging in cycles of over- and under- eating, or confining yourself to strict dietary rules, I would not recommend ketosis. In order for someone to truly achieve wellness, then psychological health must be prioritized, perhaps above whatever ketosis-based goals you may have (and of course this varies by the individual. If you have brain cancer then please feel free to try ketosis regardless of how much you love your body).

All of which is to say that…

Ketosis is very complicated. It has a common practice of very low carb dieting that has been shown to benefit some people, but it certainly does not benefit everybody. It is different for every person – so if you decide to try it, please simply be aware of potential pitfalls that may result and adjust your diet accordingly.

You can also achieve ketosis a less well-known way, which is by consuming a tablespoon or two a day of MCT oil. If you are seeking simple psychological and physiological performance gains, and are not trying to starve your body of carbohydrates, then this may be a much more safe route with which to experiment. (It would also be compatible with recommendations I make in my program for weight loss – in which you can choose to be low carb or low fat Weight  Loss Unlocked.)

In the end, however, ketosis may be good for some conditions, but is not good for everybody. Every time a new fad roles around, it is best to step around it with caution, as hype (at least in my experience of observing the health world) typically vastly overemphasizes actual results. The only way to truly know if a diet works for you is to try it – but also to do so armed with as much healthy skepticism and and self-awareness as possible.





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