It’s been a while since the last reader’s request post, and today’s topic is a meaty, somewhat controversial and currently very hot one. Nothing like some good old nutrition geekery to kick off your Monday morning, right?
If you listen to health podcasts, read nutrition blogs or otherwise keep yourself in the know about what’s trending in wellness, you’ve probably seen the ketogenic diet pop up a lot recently. A few of you have asked for my thoughts on it, and while I can’t speak from personal experience on this one because I’ve never tried the diet myself, I wanted to provide you with all the things I feel are most important to know. I’ve included my opinion of ketosis for fat loss at the end of the post, so if you’re just here for a quick skim, that’s where you’ll find it. If you’d rather take things from the top, let’s dive right in!
Disclaimer: As a reminder, I’m not a doctor and none of the material in this post is intended to be interpreted as medical advice. I would recommend checking with your doc before choosing to adopt a new dietary protocol or make other significant changes that affect your health.
The basics: What is ketosis?
In a nutshell, a ketogenic diet is a high fat, low carb, moderate protein approach to nutrition. For most of us, we break down carbohydrates from food into glucose, and our cells use that as energy. However, when a person restricts carbohydrates to a certain point, the body shifts into a state called ketosis. This is where ketones produced from stored fat are used as the primary energy source instead.
How does the body produce ketones?
Interestingly, you don’t have to consume carbohydrates for the body to find energy. Using a process called gluconeogenesis, the liver can take stored body fat and convert it into ketone bodies (a fancy name for a group of 3 molecules). After about a month(ish) of eating in this way, ketone bodies become the energy source that our cells begin to use instead.
Is it a new diet?
Nope, not at all. In the past, the ketogenic diet has been suggested for people with epilepsy. Doctors recommended it prior to the introduction of some of the drugs that many people now use to manage their seizures.
Why does it seem to be all the rage now?
The ketogenic diet is definitely in the spotlight, especially in three groups:
- Endurance athletes
- People wanting to shed body fat
- Doctors, scientists and self-proclaimed biohackers interested in the anti-inflammatory, cognitive and long-term health benefits of using an alternative to glucose as a the body’s preferred energy source.
As far as endurance sports go, the idea is that the body becomes conditioned to access and make efficient use of additional fuel that a person who isn’t ketosis wouldn’t be able to use. (Studies with supporting evidence for this have been done on endurance athletes, and if you’d like to read the more, I recommend checking out this article from Outside Online. At the time I’m writing this, I’m not sure much evidence exists in sports that demand anaerobic energy or huge muscle capacity, but I could be wrong. Feel free to correct me if you know better.)
How low is low carb?
Depending on the person, usually less than 50g per day. In the example I’m about to give you for a person on a 2,000 calorie diet, it’s 25g but what puts someone’s body into ketosis depends on the individual.
And what would this look like when it comes to daily meals?
Precision is really important, especially for beginners on a keto diet who may not have a strong understanding of how many grams of carbs are in the foods they eat. Because of this, food tracking and weighing is fairly common, as is peeing on fancy sticks (yep, you read right – measurements of ketones in urine is used as an indicator of whether you’re in ketosis or not.)
To explain how this works out in terms of macronutrient ratios, go, I made you a pretty picture:
As you probably know, carbohydrates don’t just come from starchy foods like bread, rice, quinoa and other grains, but also fruits and vegetables – everything from sweet potatoes and carrots to lettuce and green beans. Depending on how low carb a person decides to go, there is a risk of falling short on the valuable vitamins and minerals our bodies need for optimal health. I’ll pause on that though – more on the limitations of the ketogenic diet in a second.
In addition to following those general macro ratios, if fat loss is one of your goals, you’d need to also ensure that you’re at a caloric deficit. Otherwise, the fat loss benefit just won’t happen. (How large a deficit depends on a number of factors including your gender, current weight, activity level and weight loss goals.) Said another way, you can’t just eat bacon, cheese, avocado and coconut oil until your heart is content – calories matter, just like they do in any other weight loss approach.
Of course, if you decide to try adopting a ketogenic diet you’ll want to do your own research to fully understand what’s involved. These are the main things I’d want you to know:
1. There’s potential for nutrient deficiency.
Because the diet is so restrictive on carbohydrates (including fruit + vegetables), without proper supplementation, you could miss out on the valuable vitamins and nutrients your body needs for optimal health.
Here’s an example to demonstrate: Say a woman eats about 2,000 calories per day, as shown in the diagram above. We can see there that if she was restricting carbs to 5% of total daily calories, that would translate to 100 calories or 25g from carbs per day. In real food terms, check these out:
- 1 Granny Smith apple has about 22g carbs
- ½ cup strawberries = 12g carbs
- 1 cup broccoli = 6g carbs
- 1 cup of chopped zucchini = 4g carbs
As you can see, 25g adds up very quickly – and that’s just with a couple of servings of produce – not the recommended daily 10.
2. Cutting back on carbs can make you feel like crap initially.
You may have heard the term ‘keto flu’ commonly cited by people who embark on a ketogenic lifestyle. It describes the moodiness, irritability, sleep issues, fatigue, sugar cravings, crappy workouts and lack of mental clarity that often comes as a result of carb restriction and the body’s adaptation to a new energy source. From what I’ve heard, it typically lasts about a week but this varies by person. There are things you can do to make it less terrible to deal with, including:
- Ensuring you’re eating enough calories + fat – Fat is incredibly satiating, so if you suddenly switch to loads of higher-fat foods, there’s a chance you just won’t feel hungry as often and therefore may not be consuming enough calories.
- Drinking enough fluids + supplementing with salt – Insulin drops when you go low carb because less glucose in the bloodstream means less insulin is needed to balance blood sugar. This means your body will release excess water (and if you often feel bloated, this should not be the case any more.) Salt can help the body retain some of that water, keeping you more hydrated. Salt aside, drinking fluids is extremely important for hydration.
- Not trying to work out to your ‘usual’ intensity/duration – Workouts will likely already feel rough, and adding further physical stress during the adaptation phase isn’t going to do you any favours from a health perspective.
3. Your digestive system might not love it at first…
As noted above, in order to hit the macro targets AND the number of calories your body needs to sustain its basic functions (which you might not even feel the need for since fat is incredibly satiating), you’ll need to add a lot more fat to your diet than you’re used to eating. This can have implications on digestion while you adjust… and that might not be much fun!
4. Ketosis, stress + menstruation – do they play well together?
When it comes to women and ketosis, any female knows that dealing with periods, hormonal fluctuations, cramps etc that go along with it all can be enough to handle on their own without having to layer in the implications of ketosis. There’s definitely a reason why we love starchy carbs during the luteal phase of the menstrual cycle, and that’s because the rise and fall in estrogen and progesterone can bring on crazy mood swings. B-vitamins can counter that because they trigger the production of our happy hormone, serotonin. You’ll find B-vitamins in quality carbs like whole grains, avocado, nuts, seeds and dark leafy greens – all of which also contain fibre to help remove excess estrogen from the body.
Outside of menstruation, we all go through other stressful times in our lives. Again, many foods that are carbohydrate sources also provide vitamins and minerals that support the nervous system and help our bodies respond to this stress. Magnesium for example, helps us sleep and there’s tons of it in dark chocolate, a commonly reached-for food under stressful times. Sleepless and stressed does not bode well for long term compliance!
As you can see, food sources of carbohydrates have their role and stressing further about food choices without being “allowed” to consume them can add undue stress on top of what you’re already carrying. Chronic stress is not a good thing to be dealing with, so I think it’s really important to be honest about whether the time is right. This depends a LOT on your own relationship with food and how well you know yourself, and for some, it can be risky territory.
5. Maintenance can be a challenge, and tough in social situations.
Yes, restaurants these days are used to making tweaks for their customers, but like the note about macro precision above, it’s difficult to be sure when you’re not preparing the foods yourself. Failure/lack of desire to comply to the restrictive nature of the ketogenic diet is one of the reasons very commonly cited in studies done so far.1,2,3
6. It’s more of a lifestyle, not a short-term tactic.
While it doesn’t have to be a forever thing, getting fat loss results from being in ketosis isn’t an approach you can expect results with if you only try it out for, say, 2-3 weeks. The body needs time to adapt to using fat efficiently as a fuel source, and depending on a number of factors including your current carb intake and the levels of insulin your pancreas is used to cranking out, it can take longer.
Ok, so who could it be helpful for?
With all those caveats explained, there are plenty of people who have seen awesome results from going keto. Generally, they:
- Are willing to commit to this eating approach for a longer period of time
- Have been trying to shift stubborn body fat but other methods haven’t worked
- Could be dealing with epilepsy or other serious health condition and want to try an alternative/complimentary approach to medication. (Obviously this is something that should be discuss with a doc – I’m definitely not a specialist in this area.)
[Tweet “Reader’s Request: Ketogenic Diet Basics #nutrition”]
My opinion on keto for fat loss
I’ve been asked a few times lately what I think about this, and again, can’t fully say yes or no because it’s not an eating style I’ve experimented with. There are a lot of cautions above, which probably makes it look like I’m against keto but that’s not the case.
To be clear, what I do believe is that by following a ketogenic diet or any other diet rooted in real whole foods – that could be paleo, vegan, vegetarian etc – naturally, the processed foods that many seeking to shed fat currently eat get crowded out. Of course, when that happens, positive results are far more likely regardless of the macro ratios.
Bottom line: What’s best for you is a matter of what fits with your lifestyle. Food should be fun, delicious, and nourishing. As mentioned earlier, if following this way of eating (or any) causes you a lot of stress and potentially jeopardizes your relationship with food, I’d caution against it. If it fits, then rock on!
So with allllll that said, now I’d love to hear your thoughts too. What do you think about the ketogenic diet? Tried it? Not a fan? Still not sure? Chime in below!