It’s been a while since I last wrote about keto, so I figured that it’s a good time for an updated keto diet review, since this diet is still wildly popular.

When someone comes to me and asks me if they should try a particular diet or eating plan, the first thing I assess is whether or not it’s a plan that’s physically or emotionally dangerous. The second thing I look at is whether or not it’s sustainable. Because really, those are the things that really matter the most: is it going to hurt you, and are you going to be able to stick with it for more than three days.

I guess we should throw in ‘why are you going on a diet in the first place?’, but that’s a whole other post (and my book, Good Food, Bad Diet)

A lot of people believe that because I’m a dietitian, I’m automatically against low-carb diets. That’s completely false! I’m pro any way of eating that makes you happy and healthy. 

What is Ketosis?

Ketosis is a state that your body goes into when it doesn’t get enough carbohydrate, either because you’re starving or, because you’re intentionally restricting carbs. 

The body’s first line for fuel is carbohydrate that it breaks down into glucose. When carbs are scarce, our bodies are adapted to break down fat for fuel so we don’t starve to death. 

To do this, the body starts a process called ketogenesis – essentially meaning ‘the making of ketones’, during which the liver converts fat to ketones. These ketones are used by your body as fuel instead of glucose, and this is how the ketogenic diet works: using fat for energy. 

We aren’t really sure how people end up losing weight on the ketogenic diet, but it could be multifactorial: likely because ultra-processed food isn’t allowed, so there goes that. Also, a diet that’s mostly fat is extremely satiating, so you’re not snacking every half hour, and your calorie intake naturally decreases, leading to weight loss.

Insulin levels drop when we don’t consume carbs, which some people believe helps us burn fat. This carbohydrate insulin hypothesis is just that – a hypothesis – and hasn’t been definitively proven by research (and here). 

We can’t talk about the ketogenic diet without mentioning DIETFITS, which was published in February, 2018. This year-long, comprehensive (and very well done, I might add) study pitted low carb and low fat diets against each other to prove various hypotheses. Click on the link if you want to see the study and its methodology, including carb and fat levels at each stage.

As always, my fave site has the best synopsis of the study I’ve read to date (here)

Here’s what the study found:

1. As far as the insulin-carbohydrate theory, DIETFITS found that insulin levels did not affect weight loss. And even though it was funded by a low-carb group, the study proceeded to poke major holes in their insulin theory. Ooops! 

2. For which diet caused more weight loss, DIETFITS found that while the low carb group lost more weight initially, the whole thing evened out over the course of the year, ending up with both groups within two pounds of each other. 

3. The best diet is the diet you can stick to. 

You’ll probably lose weight initially on the keto diet because you’re dumping glycogen, which binds several times its weight in water. Once all that water is gone, you’ll be down a few pounds, which can be inspiring.

The hard work begins when you achieve ketosis – usually in around 72 hours after starting the diet – and need to keep yourself there.

What is the Keto Diet?

While keto may be easy for some, it can be very challenging for most. That’s because to be in ketosis, you need to eat around 75+% of your calories from fat. That’s a load of fat, and if you break ketosis by having a piece of bread or more than a few berries, the diet stops working and the weight you lost becomes a sweet memory.

The level of carbohydrate that each person can eat and still be in ketosis varies – some people can’t eat more than 20 grams a day; some people can eat 50. It’s still going to be a hell of a lot fewer carbs than you’re probably used to eating on your normal diet.

The keto diet isn’t high-protein, and in fact, too much protein may kick you out of ketosis, so it’s not as though you’re going to be mowing your way through piles of steaks and meatballs all day long. 

What does a Keto Diet Look Like?

The keto diet macros look something like this:

Of total daily calories:

Fat: 75+%

Protein: ~15%

Carbs: ~5%

A typical day on the keto diet looks like this. 

Breakfast: Coffee with grass-fed butter and MCT oil, or eggs fried in butter with greens.

Lunch: Big salad made with greens and avocado, plus salmon or another sort of protein.

Dinner: Steak with asparagus.

Snacks: Nuts, seeds, cheese and vegetables, meat jerky.

There’s also what is aptly called the ‘dirty keto’ diet, which is comprised of low-carb fast and ultra-processed food. I’m not sure why anyone would want to eat this food three times a day, and I definitely don’t recommend this version of the diet simply due to its high levels of unhealthy fats. 

If you don’t reach your daily fat quota, there are ‘fat bombs’ comprised mostly of things like coconut oil, sweetener, and unsweetened chocolate to help you…sort of like a keto sweet of sorts. 

The meal plan above doesn’t seem too bad, does it? I mean, it’s mostly whole foods, and it includes lots of things that most of you probably love, like steak and cheese. 

Not allowed are dairy except for butter and cream; most fruits, legumes like chickpeas and lentils, breads, pasta, potatoes, real pizza crust, any sweets that aren’t keto, etc. You have to work hard to make sure that you’re getting adequate fiber in your diet, since many fiber-rich foods are off the table with this diet.

The issue comes when you start to want birthday cake on your birthday…or in the summer, when the peaches are ripe…or when you go out with friends and want a few glasses of wine…or when it’s pizza night…you get what I’m talking about. Are you going to be able to eat this diet and still feel fulfilled in other areas of your life? Think carefully.

As far as plant-based keto, it can be done, but it entails a shitload of nuts, some tofu, seitan, and protein powder. 

This panfried prosciutto is definitely a keto-friendly food!

Ketogenic Claims: Weight Loss and a Cure for Cancer?

The ketogenic diet has been used for years to treat people with epilepsy, in particular children.

It has only recently been discovered as a weight-loss diet, and there are other, more dubious claims for it as well, including that it prevents aging, ‘burns fat forever’, and effectively cures cancer and diabetes.

None of these are true, and the last two are just egregious. If you have type two diabetes, a low-carb diet may help lower your blood sugars, but it won’t put the disease into remission, since that would mean that you wouldn’t have diabetes even if you went off the ketogenic diet.

Nothing cures type one diabetes except for a pancreatic transplant, that’s that. 

The fat burning claim is a vastly overplayed dud; While ketogenic diets burn fat for fuel, they’re not proven to do so in the long term any more efficiently than low-calorie diets. If you’ve read my blog, you’ll know how I feel about ‘fat burning’ claims. Spoiler: I can’t stand them.

To say that a diet cures cancer is untrue and potentially harmful. If a cancer patient is convinced to try a diet or any ‘alternative’ treatment instead of chemo, studies show they have a decreased chance of survival. If they’re on chemo and also on a keto diet, the changes in blood work that may occur from the diet may prevent them from continuing on with their chemo, creating a dire situation in which they have to stop treatment until their blood work corrects itself. 

No diet cures cancer. No diet has EVER cured cancer. 

While we all sincerely wish this was the case, it’s unfortunately not. And no, I’m not ‘in the pocket of Big Pharma’.

In terms of exercise, regardless of what the people at your Crossfit box say, research lands squarely in the ‘carbs for fuel’ camp. (and here) Meaning, the keto diet probably does not improve most peoples’ exercise performance. In cases that it does, the athletes must be keto-adapted for several months before they see the benefits.

Losing weight on a ketogenic diet can also make exercise easier for some people, which can improve performance. 

There is emerging research for the ketogenic diet and brain cancer – not as a cure, mind you, and neurological diseases such as MS and Parkinson’s disease, as well as IBS and IBD. Many of of the studies done on disease and keto have only been done on animals, and many are small or single studies, so when I say that the research is ‘emerging’, that doesn’t mean ‘believe it like it’s gospel’.

It means, ‘more studies – big, human, and well-designed studies – are required’. But right now, there is some positive research coming out about keto being an adjunct to brain cancer therapy.

In terms of the resolution of IBS symptoms on the keto diet, it may very well be the elimination of fermentable carbohydrates, called FODMAPS, that is responsible for this outcome. 

Love peaches? Sorry, not allowed on keto.

Fat loss is I believe one of the most common reasons why people would choose a ketogenic diet, but because it’s so difficult to follow, and because it doesn’t work for everyone, it’s tough for me to make a blanket recommendation for this diet. But that’s not big news: I’ll never make a blanket recommendation for any diet. Why would I ever do that? You’re all different, and my job is recommending different things for different people.

That’s because I want to make sure that each individual eats in a way that works for them. 

There are hundreds of doctors, dietitians, and other professionals who recommend nothing but keto for everyone. I take issue with anyone in a position of trust who pushes one particular diet on every single person, because that behaviour completely disregards peoples’ unique preferences, lifestyles, and health histories.

Our jobs as professionals is to take all of that into account before recommending any particular eating plan. *end rant*

Like most things in life, with the keto diet, there are benefits and drawbacks.

The Benefits of the Keto Diet

Your blood lipids and blood sugars might improve. There is some evidence that harmful blood cholesterol levels may decrease with a ketogenic diet, but this doesn’t happen with everyone. In fact, some people on keto may experience higher cholesterol levels. As far as blood sugars, a ketogenic diet may help manage glucose levels.

You’ll most likely lose weight. Not everybody loses weight on a ketogenic diet, but many do. 

Some people report feeling an increased sense of wellbeing and more energy.

Unless you’re doing the ‘dirty keto’, you’ll be cutting out most ultra-processed foods. This is great! You might have to plan ahead in some situations – ie holidays and vacations, but forcing you to eat fewer ultra-processed foods is a definitely plus for keto.

The Downsides of the Keto Diet

It can be expensive. Buying a ton of animal protein and avoiding cheaper proteins can be costly. 

It can be socially isolating. It can be hard to navigate social occasions when you’re following keto and can’t eat a lot of what everyone else is eating…unless they’re also doing keto. Most of the time, making meals keto is an easy fix, but think of how it will make you feel to have to make those adjustments in different situations.

It can make you feel terrible. Keto flu, lack of energy, mood swings from no carbs…we all react differently, and some of these things disappear after a week or two, but sometimes not.

Sweeteners can make you fart. Keto relies a lot on sugar alcohols as sweeteners, and they can cause major gastro distress. The diet can also cause constipation and bad breath.

It can make your bad cholesterol levels rise. Just as cholesterol levels decrease in some people, some people have the opposite effect.

You can’t go on and off the diet – you must stick to it religiously. 

Saturated fats are still not healthy. There are plenty of people on the internet saying that saturated fats are healthy. Some of them even claim that olive oil is harmful. 

These people are wrong. If you do keto, make most of your fats the healthier type – avocado, nuts, and olive oil. 

It’s very limited. You can’t have most dairy, or bread, legumes, sweets, fruit, am I missing something? You get the point. 

It’s tough to maintain for the long-term. 

My Final Thoughts on the Keto Diet

The ketogenic diet may help some people lose weight and control their blood sugars, but it’s extremely restrictive, and it’s definitely not a ‘cure’ for disease. 

If you stray from the diet, you’ll gain the weight back fairly quickly. This can lead to weight cycling, which can be emotionally tough. Yo-yo dieting isn’t fun.

As with every diet, consider the cost benefit (read about it here). Emotionally, socially, financially, and physically – what is this diet going to cost you? Is it worth it? Can you deal with these costs for the long-term, especially knowing that the ‘benefits’ disappear as soon as you go off the diet? Is it going to destroy your relationship with food? How is counting carbs to the last gram – even in ‘healthy’ foods like vegetables – going to affect you?

These are valuable questions that you should be asking yourself.

And when you’re researching keto or any other diet online, please remember that n=1 doesn’t mean a hell of a lot. Even lots of n=1s doesn’t equal science…it just equals a lot of people who are telling you what you want to hear.

It’s easy to find favourable anecdotes about keto, but we don’t often hear from the people who aren’t successful on it or other diets. That’s because many people who fail at diets may feel shame at disclosing that.

Just so you know, I believe that there are far, far, more people who have failed at keto (and every other diet) than there are people who have managed to maintain this way of eating for over 5 years. Be objective, thorough, and realistic when you’re doing research on any eating plan.

Don’t just blindly jump into it telling yourself you’ll ‘make it work’; measure it against your particular lifestyle, preferences, financials, etc. 

And lastly, remember: If keto isn’t for you but you still want to try a low-carb diet, go ahead and do it! If you’re currently eating a high-carb, high ultra-processed food diet, you don’t necessarily have to go all the way into a keto diet in order to reduce carbs. Something with a bit higher level of (healthy) carbs might be more sustainable for you long-term, and whole lot more enjoyable.