5 of the worst keto diet side effects

The keto diet can help with weight loss, but at what cost?

  • In addition to weight loss, there are a few well-known side effects of the keto diet, some of which can be unpleasant.
  • Some side effects of the keto diet are bound to occur, though others only happen when the diet is implemented poorly.
  • The keto diet doesn't have to lead to a host of negative side effects, but anyone considering undertaking the diet over the long term should be especially careful.

The keto diet is often called a fad diet. Make no mistake: it is. But unlike other trendy diets, the keto diet is unique because it actually pushes the body into an alternate, natural metabolic state called ketosis. When this happens, you can reliably expect a few negative side effects, notably those that come with the "keto flu." But other side effects emerge only when people implement the keto diet poorly, typically by failing to eat balanced, nutrient-rich foods as a part of a high-fat, low-carb diet.

Here are a few of the worst side effects of the keto diet, most of which can be avoided with some careful planning.

​Constipation

What's likely to happen when you cut out common sources of fiber from your diet? Constipation. A 2015 study involving children on the keto diet showed that regular constipation was extremely common among participants, affecting about 65 percent of them.

"Many of the richest sources of fiber, like beans, fruit, and whole grains are restricted on the ketogenic diet," registered dietician Edwina Clark told Everyday Health. "As a result, ketogenic eaters miss out on the benefits of fiber-rich diet such as regular laxation and microbiome support. The microbiome has been implicated in everything from immune function to mental health."

Still, the keto diet doesn't need to lead to fiber deficiency: avocados, flaxseed, almonds, pecans and chia seeds can all provide fiber while still keeping you in ketosis — when consumed in the right amounts.

Vitamin deficiency

Any diet that prohibits you from eating many types of fruits, vegetables and other foods is bound to leave you vulnerable to vitamin and mineral deficiencies, and it's for this reason many doctors only advise going on the keto diet over the short term.

"Keto is not a great long-term diet, as it is not a balanced diet," Nancy Rahnama, M.D., M.S., an internal medicine and bariatric specialist, told Reader's Digest. "A diet that is devoid of fruit and vegetables will result in long-term micronutrient deficiencies that can have other consequences. The keto diet can be used for short-term fat loss, as long as it is under medical supervision."

On the keto diet, your body begins to shed fat, water and glycogen, and as this happens you lose key electrolytes, such as sodium, potassium and magnesium. When you're running low on these electrolytes, you might experience headaches or extreme fatigue. These losses are most pronounced during the first few weeks after you enter ketosis, so if you're going to start the keto diet it's best to plan ahead to make sure you get healthy amounts of these electrolytes — and other vitamins and minerals — either through supplements or a thoughtfully-designed meal plan.

​Muscle loss

Some research suggests that the keto diet can lead to the loss of lean body mass, which includes muscle protein.

"Muscle loss on the ketogenic diet is an ongoing area of research," Clark told Everyday Health. "Small studies suggest that people on the ketogenic diet lose muscle even when they continue resistance training. This may be related to the fact that protein alone is less effective for muscle building than protein and carbohydrates together after exercise."

The website sci-fit, which compiled a survey of the research on the keto diet, found:

"We generally see greater lean body mass (LBM) loss in ketogenic diet groups. Note that lean body mass contains water, glycogen, and muscle protein, by definition. It is hard to say with certainty that LBM loss implies greater "dry" muscle protein loss. "Wet" LBM can come and go quickly because it consists of water and glycogen."

In terms of gaining muscle, it seems protein alone doesn't do as well as it does when paired with complex carbs. These carbs don't become part of the muscle fiber, but they do help speed up the process, in part by helping cells regain glycogen — a key source of fuel during exercise.

The 'keto flu'

One of the most immediate side effects of the keto diet is the "keto flu," a suite of symptoms that many experience in the first couple weeks after entering ketosis. Similar to the flu, these symptoms can include fatigue, brain fog, dizziness, vomiting, nausea and stomach pain.

"The keto flu is definitely real," registered dietician Scott Keatley told Everyday Health. "Your body functions really well on carbohydrates — that's what it was designed for. When it switches to fat burning, it becomes less efficient at making energy."

The keto flu — and the accompanying sugar cravings – often leads people to give up the diet and begin scarfing down carbs, but those who stick it out usually report that the symptoms clear up after a few days or a couple weeks.

Kidney damage

Some people inflict damage on their kidneys when they switch to the kidney diet because they eat too much meat and don't drink enough water. This can lead to an increase in uric acid, which is known to cause kidney stones.

"If you're going to do keto, there's a better and a worse way to do it," registered dietician Kim Yawitz told Everyday Health. "Loading your plate with meats, and especially processed meats, may increase your risk for kidney stones and gout... High intake of animal proteins makes your urine more acidic and increases calcium and uric acid levels. This combination makes you more susceptible to kidney stones, while high uric acid can increase your risk for gout."

Of course, a responsible keto diet plan need not result in damage to the kidneys. In addition to monitoring meat consumption, a 2007 study on kidney stone development within young participants on the keto diet found that taking oral potassium citrate tablets seemed to be effective at preventing kidney stones.

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Why Epicurean ideas suit the challenges of modern secular life

Sure, Epicureans focused on seeking pleasure – but they also did so much more.

Antonio Masiello/Getty Images
Culture & Religion

'The pursuit of Happiness' is a famous phrase in a famous document, the United States Declaration of Independence (1776). But few know that its author was inspired by an ancient Greek philosopher, Epicurus. Thomas Jefferson considered himself an Epicurean. He probably found the phrase in John Locke, who, like Thomas Hobbes, David Hume and Adam Smith, had also been influenced by Epicurus.

Nowadays, educated English-speaking urbanites might call you an epicure if you complain to a waiter about over-salted soup, and stoical if you don't. In the popular mind, an epicure fine-tunes pleasure, consuming beautifully, while a stoic lives a life of virtue, pleasure sublimated for good. But this doesn't do justice to Epicurus, who came closest of all the ancient philosophers to understanding the challenges of modern secular life.

Epicureanism competed with Stoicism to dominate Greek and Roman culture. Born in 341 BCE, only six years after Plato's death, Epicurus came of age at a good time to achieve influence. He was 18 when Alexander the Great died at the tail end of classical Greece – identified through its collection of independent city-states – and the emergence of the dynastic rule that spread across the Persian Empire. Zeno, who founded Stoicism in Cyprus and later taught it in Athens, lived during the same period. Later, the Roman Stoic Seneca both critiqued Epicurus and quoted him favourably.

Today, these two great contesting philosophies of ancient times have been reduced to attitudes about comfort and pleasure – will you send back the soup or not? That very misunderstanding tells me that Epicurean ideas won, hands down, though bowdlerised, without the full logic of the philosophy. Epicureans were concerned with how people felt. The Stoics focused on a hierarchy of value. If the Stoics had won, stoical would now mean noble and an epicure would be trivial.

Epicureans did focus on seeking pleasure – but they did so much more. They talked as much about reducing pain – and even more about being rational. They were interested in intelligent living, an idea that has evolved in our day to mean knowledgeable consumption. But equating knowing what will make you happiest with knowing the best wine means Epicurus is misunderstood.

The rationality he wedded to democracy relied on science. We now know Epicurus mainly through a poem, De rerum natura, or 'On the Nature of Things', a 7,400 line exposition by the Roman philosopher Lucretius, who lived c250 years after Epicurus. The poem was circulated only among a small number of people of letters until it was said to be rediscovered in the 15th century, when it radically challenged Christianity.

Its principles read as astonishingly modern, down to the physics. In six books, Lucretius states that everything is made of invisible particles, space and time are infinite, nature is an endless experiment, human society began as a battle to survive, there is no afterlife, religions are cruel delusions, and the universe has no clear purpose. The world is material – with a smidgen of free will. How should we live? Rationally, by dropping illusion. False ideas largely make us unhappy. If we minimise the pain they cause, we maximise our pleasure.

Secular moderns are so Epicurean that we might not hear this thunderclap. He didn't stress perfectionism or fine discriminations in pleasure – sending back the soup. He understood what the Buddhists call samsara, the suffering of endless craving. Pleasures are poisoned when we require that they do not end. So, for example, it is natural to enjoy sex, but sex will make you unhappy if you hope to possess your lover for all time.

Epicurus also seems uncannily modern in his attitude to parenting. Children are likely to bring at least as much pain as pleasure, he noted, so you might want to skip it. Modern couples who choose to be 'child-free' fit within the largely Epicurean culture we have today. Does it make sense to tell people to pursue their happiness and then expect them to take on decades of responsibility for other humans? Well, maybe, if you seek meaning. Our idea of meaning is something like the virtue embraced by the Stoics, who claimed it would bring you happiness.

Both the Stoics and the Epicureans understood that some good things are better than others. Thus you necessarily run into choices, and the need to forgo one good to protect or gain another. When you make those choices wisely, you'll be happier. But the Stoics think you'll be acting in line with a grand plan by a just grand designer, and the Epicureans don't.

As secular moderns, we pursue short-term happiness and achieve deeper pleasure in work well done. We seek the esteem of peers. It all makes sense in the light of science, which has documented that happiness for most of us arises from social ties – not the perfect rose garden or a closet of haute couture. Epicurus would not only appreciate the science, but was a big fan of friendship.

The Stoics and Epicureans diverge when it comes to politics. Epicurus thought politics brought only frustration. The Stoics believed that you should engage in politics as virtuously as you can. Here in the US where I live, half the country refrains from voting in non-presidential years, which seems Epicurean at heart.

Yet Epicurus was a democrat. In a garden on the outskirts of Athens, he set up a school scandalously open to women and slaves – a practice that his contemporaries saw as proof of his depravity. When Jefferson advocated education for American slaves, he might have had Epicurus in mind.

I imagine Epicurus would see far more consumption than necessary in my own American life and too little self-discipline. Above all, he wanted us to take responsibility for our choices. Here he is in his Letter to Menoeceus:

For it is not drinking bouts and continuous partying and enjoying boys and women, or consuming fish and the other dainties of an extravagant table, which produce the pleasant life, but sober calculation which searches out the reasons for every choice and avoidance and drives out the opinions which are the source of the greatest turmoil for men's souls.

Do you see the 'pursuit of happiness' as a tough research project and kick yourself when you're glum? You're Epicurean. We think of the Stoics as tougher, but they provided the comfort of faith. Accept your fate, they said. Epicurus said: It's a mess. Be smarter than the rest of them. How modern can you get?Aeon counter – do not remove

This article was originally published at Aeon and has been republished under Creative Commons. Read the original article.


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