is the keto diet good for you

What you need to understand about keto, without the controversy

So this is why people keep flaming each other in your Instagram feed.

Nothing gets you called a “jackhole” faster than questioning the keto diet in a public forum. That’s what happened to Jillian Michaels recently when she was featured in a Women’s Health video calling the keto diet a “bad plan.” Despite the name calling, Michaels handled herself with aplomb and suggested a debate on the science of keto. If you’re trying to learn how to lose weight and keep it off, you’ve probably considered the low-carb plan. So if you’re wondering is the keto diet good for you, and don’t know where to begin on the science — start here. Here’s what you need to understand about not only the diet but also the hype and debate.

What is the keto diet?

First we need to clear up some confusion. Since keto went mainstream, several different variations, all referred to as “keto,” have emerged. And that can make things confusing. Very simply, the keto diet is a low-carb, moderate-protein, high-fat way of eating. It’s important to talk about protein, because the keto diet isn’t simply a low-carb plan. The goal is to keep your body in ketosis. When that happens, your body more efficiently burns fat for fuel.

The keto diet is a medical intervention that has been around for decades. The low-carb plan as we know it today actually dates back to the 1920s when it was used to control seizures in patients. Click To Tweet

This isn’t in question. Your body simply has to, and this effect is backed by science. Our bodies do burn carbohydrates for fuel first, which means you’re burning less fat if you include carbs in your diet. Your body has to burn through those first to even start tapping into fat. And, yes, researchers have looked into whether this holds true for athletes. More on that later. In order to force your body into ketosis, most of these plans keep carbs at roughly 5% of the daily diet. And yes, vegetables count toward that number.

But there are different types of keto diets

The standard ketogenic diet (SKD) is the foundation and what we’ll discuss for most of this article. But there are variations, which is why any debate about the keto diet and its health benefits gets confusing, and quickly. Here are the biggest types of keto diet you’ll hear people talk about as well as the macro breakdown for each of them:

  • The standard ketogenic diet (SKD) calls for 75% of daily calories from fat, 20% from protein, and a scant 5% from carbohydrates.

  • The high-protein ketogenic diet is pretty close to the standard version, except more protein is allowed. That causes some controversy, which we’ll get to later. This approach calls for roughly 60% of daily calories from fat, 35% from protein, and again, 20% from carbohydrates.

  • The cyclical ketogenic diet (CKD) uses the standard keto diet as its base, except carbohydrate refeeds are allowed. Patterns differ, but that could look like 5 days on a standard ketogenic diet followed by 2 high-carb days.

  • The targeted ketogenic diet (TKD) is harder to pin down for exact numbers. That’s because your day is spent on the standard ketogenic diet, but you add carbs to your meals around workouts (when your body most efficiently uses them).

And there’s something you need to understand about keto

Yes, the rise in popularity of the keto diet makes it look like a fad. But it’s not. The keto diet is a medical intervention that has been around for decades. The low-carb plan as we know it today actually dates back to the 1920s when it was used to control seizures in patients. There’s strong medical evidence that the keto diet is an effective intervention for people living with epilepsy. In many cases, the diet allows patients to reduce or even stop their use of anti-seizure medication. (For the record, fasting and other dietary interventions have been used to treat epilepsy since at least 500 BC.)

There are other science-backed benefits of the keto diet

The problem with this debate is simple. Ask someone on either side and you’ll get a very polarized answer. Keto is the ultimate way or eating, or the worst thing you could do for your body. As with all things, the real answer lies somewhere in between. But because it’s a diet, it’s even more complicated since we all react differently to eating plans.

But there is science behind some of the health benefits of the keto diet. Briefly, here’s what they’ve found keto can do within scientific studies:

It’s important to keep in mind, though, that many of these findings aren’t conclusive. The studies were small, they need to replicated. Although these are reasons you might want to try keto, these results are far from guaranteed.

Are there side effects of the keto diet?

Positive and negative, yes. Carbohydrates have a water molecule attached to them. That means when you go on a low-carb plan or shun these foods for a while, you’ll lose some water weight right away. Don’t mistake this for actual weight loss, however. If you go back to eating carbs, even in moderation, that weight will return.

You’ve also probably heard of the keto flu. This refers to the group of side effects people suffer as they get used to the new plan. Although many sites will tell you it lasts only a couple days, talk to a couple people who have gone keto and it’s clear that window can last even a couple weeks. The severity of symptoms varies by person, so it’s hard to say what you might experience if you give the diet plan a try. You might not experience them all, but symptoms of the keto flu can include:

  • Nausea
  • Vomiting
  • Constipation
  • Diarrhea
  • Headache
  • Irritability
  • Weakness
  • Muscle cramps
  • Dizziness
  • Poor concentration
  • Stomach pain
  • Muscle soreness
  • Difficulty sleeping
  • Sugar cravings

Generally, taking it slow is best way to ease and even prevent symptoms of the keto flu. That means backing off of your workout intensity for a couple days or weeks. It can also help to log a couple of moderate-carb weeks before committing to low-carb to smooth the transition. Staying hydrated is also key since your body will let go of plenty of water in the beginning.

Why is there so much controversy around the keto diet?

Tracing the debate back to one reason isn’t possible. Detractors cite plenty of reasons for disagreeing with the low-carb plan, including Michaels who says it’s a bad plan “for a million reasons.” We’ll break down the biggest subjects of debate, though this doesn’t cover every reason people avoid the plan. And, yes, it’s undeniable that some of the online hate is a reaction to keto zealots who claim it’s the only way to eat. (Spoiler: It’s not. Calm down.)

Athletic performance

In athletic circles, you’ll see keto hotly debated. That’s because your muscles store carbohydrates as glycogen (unless your stores are full, in which case they’re stored as fat). Glycogen is what your muscles tap into during a workout, specifically those that are strength-based like weight lifting. Many strength athletes argue that keto hinders performance because of the lack of carbs and, therefore, glycogen.

There have been studies on athletic performance and the keto diet. Athletes in one study didn’t see any loss of performance from a 4-week keto diet. But it’s worth noting a couple things here. The participants were bikers, not weight lifters. The study was also relatively short-term. Maintaining performance for a month is different from trying to perform the same after a year on a restrictive diet plan.

In a different, more recent, study, a keto diet did hurt anaerobic performance of athletes. The participants’ strength dropped by 7% and running distance took a 15% hit. But, again, you need to take some notes about the study itself. Participants were only “carbohydrate starved” for four days for this study. That gives us very little insight into the long-terms effects of the keto diet on performance in the gym.


This seems to be what Michael was getting at in her Women’s Health video. She said the diet deprives your body of essential nutrients. “Your cells, your macro molecules, are literally made up of protein, fat, carbohydrates, nucleic acids. When you do not eat one of the three macronutrients — those three things I just mentioned — you’re starving yourselves,” she said. “Those macronutrients serve a very important purpose for your overall health and wellbeing. Each and every one of them.”

The keto diet can help you get your insulin levels under control. Maybe that means it’s right for you for right now. Sometimes diets, like friends, play an important role in your life for a short time, and then it’s time to let go. Click To Tweet

That’s exactly why she’s previously called keto a “fad diet” and urged, “don’t do keto.” She wants people to follow an approach with common sense, instead. “Balanced diet is key” to Michaels. The crux of the matter is it’s really hard to eliminate an entire food group for longer than a couple weeks. Giving up pizza doesn’t mean you stop liking or craving pizza. And cauliflower crust versions only take you so far.

Some health experts argue that burning fat for fuel is a survival mechanism of our bodies. It’s an amazing adaptation and essential, but not something we should willingly force on ourselves. And you can measure that stress on the body. Following a keto diet raises cortisol levels. Keto fans claim cortisol levels decrease again once you get into ketosis, but slip up on the diet and you’ll send your cortisol levels back on this roller coaster. Over time, elevated levels of cortisol can cause serious health conditions.

is the keto diet good for you eggs

What can we learn from the keto diet?

Completely separately from whether or not we’ll follow the plan, what can the keto diet teach us? It’s easy to either jump on or roll your eyes like a bored teenager at food and diet trends. (Again, it has a lot to do with zealots who try to tell you it’s the only way to eat or live.) But if you take the time to dissect the basic ideas, most have valuable lessons. In the case of the celery juice challenge, that was consistency with your nutrition and weight loss efforts. So what is it for keto? I think there’s a couple things everyone can take away here.

Food as medicine

First and foremost, that a diet can be a legitimate medical treatment and that holistic options should be considered in tandem with medication. Go to your doctor regularly — seriously, I know many of you don’t — and keep an eye on your blood levels. You can catch if you’re creeping towards conditions like prediabetes and actually reverse the trend with your diet. Food can be transformative. The keto diet can help you get your insulin levels and insulin resistance under control. Maybe that means it’s right for you for right now. Sometimes diets, like friends, play an important role in your life for a short time, and then it’s time to let go.

Why is keto so controversial? It’s undeniable that some of the online hate is a reaction to keto zealots who claim it’s the only way to eat. Spoiler: it's not. Click To Tweet

Diets are individual

Related to that point, the controversy should really teach us all that dieting is personal. What works for me might not work for keto Kevin. Your friend might sail through the keto flu after a couple days, while you might suffer in this energy trough for two weeks. From our prefered eating patterns to our gut bacteria, we’re unique. Which also means we’re sort of in this weight loss thing alone, despite what cookie cutter dieting programs want you to believe.

One of the biggest studies done on the low-carb versus low-fat debate found that there was no statistically significant difference in weight loss achieved. And while that sounds like even researchers can’t find the best diet, it’s actually a good thing. It means that whatever you can stick to is what will work best for you. So if you like carbs, you’re better off passing on keto, even though there’s science behind some of its health benefits. (And despite all the memes your friend keeps sending you on Instagram.)

Is the keto diet good for you? The dirt on this diet plan

So, is the keto diet good for you? The long and short of it is this: If you enjoy the high-fat, low-carb diet, eat that way. But if it’s a struggle to give up carbs, you’re no worse off for passing on the keto trend. There are some health conditions, like high blood sugar and epilepsy, that may benefit from the diet. But some people will be able to follow keto for only a short time to course-correct their health issues. The best diet, at the end of the day, is the one you can stick to long-term.