The Keto Diet Explained: Is the Popular Weight Loss Regimen Effective?

In the last decade or so, the Ketogenic — or "keto diet" — has garnered tremendous popularity among celebrities and everyday dieters alike because you can eat so many great-tasting foods. However, Woman's World interviewed dieticians who didn't necessarily think it was an effective long-term answer to weight loss.

Despite its recent fame, the low-carbohydrate, high fat regime has been around for over a century, according to a review from Harvard University — in the 1900s, it was used to treat epilepsy, among other conditions.

Decades after becoming widely recognized for its metabolic effects in the 1960s, though, it’s since risen to fame as a staple weight loss method. Why? Dietician Stephanie Graziano, RD, CDN, CDCES explains it’s because a high fat diet means tasty food is allowed.

The Keto Diet Is Appealing Because The Foods Taste Great

Grilled meat and vegetables
A keto-friendly meal might include grilled meat and vegetables.
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“The main reason why the ketogenic diet approach has gained so much popularity is that it's very palatable,” Stephanie tells us. “Fatty foods taste good and let's face it, eating bacon, butter, cheese and meat appeals way more to most people than having to scale way back on all of those foods and choose low-fat versions instead, which often tastes weird.”

First, the Keto Diet Burns off Water Weight, Before Fat Stores

Those on the keto diet reduce their carbohydrate intake to 50 grams or less per day — replacing carbs with fat and protein for as little as three weeks, or for as long as 12 months, according to a study published to European Journal of Clinical Nutrition. Instead of using energy stored by carbohydrates, your body essentially starts to break down fat, resulting in weight loss, and the highly coveted “ketosis.” This can happen in as little as three days.

“Ketosis is when your body shifts to burning fat instead of glucose which then triggers an increase in ketone production,” Chrissy Barth, MS, RDN of Epic Biology in Phoenix, Arizona, explains. “Signs might include changes in breath odor, appetite, and energy levels.”

  • The Keto diet reduces carbohydrates to under 50 grams/day

  • Carbohydrates are replaced with proteins and fats for up to 12 months

  • The goal is to shift to ketosis, when your body starts burning stubborn fat

Weight Loss Rate Depends On Following the Diet

A woman steps on a bathroom scale.
Keto dieters sometimes see early weight changes due to water loss, rather than fat burning.
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But the rate at which dieters lose weight is contingent on several factors, Megan Lee, RD, adds. That includes on body type, and how strictly the dieter adheres to the rules of the ketogenic diet.

“The rate at which one may lose weight depends on a their adherence to a low carbohydrate intake and their total calorie intake and energy expenditure,” she says.

Ketosis is typically achieved when someone consumes less than 50 grams of carbohydrates a day – the equivalent found in two slices of bread or two medium sized fruits. If one is not stringent and consumes more than 50 grams of carbohydrates a day, ketosis will not be established or maintained, meaning the ability to prioritize the use of fat for fuel is diminished.

Megan Lee, RD

Related: MDs Reveal a Surprising Side Effect of the Keto Diet + Easy Ways to Sidestep It

Quick Short-Term Results May Just Be Water Loss

The short-term results may get dieters excited about the number on the scale, but not all of those pounds can be attributed to fat loss. According to a report published by the National Institutes of Health, although the diet seems to have a quick payoff, those following the diet are primarily losing water weight in those first two weeks, thanks to a diuretic effect.

Woman checks weight
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“Numerous studies on weight loss have demonstrated that transitioning to a keto diet can lead to both immediate and sustained weight reduction,” Chrissy Barth says.

In the initial week, rapid weight loss is often observed, primarily due to shedding water weight rather than fat loss. Following this initial decline in water weight, consistent fat loss should continue, as long as one adheres to the keto diet and maintains a calorie deficit.

Chrissy Barth, MS, RDN

Long-Term, Keto Can Be Tricky To Stick With

Long-term, the keto diet is said to reduce BMI and body weight. According to a study published to the National Library of Medicine, tests have shown the diet has can also decrease LDL cholesterol, blood sugar, and triglycerides, while raising HDL cholesterol in obese patients.

Dieters should also continue to avoid processed foods and large amounts of sugar, to keep the weight off.

In terms of maintenance, Kayli Anderson, RDN of Everyday Health recommends lowering the amount of fat you’re consuming post-diet, while re-incorporating whole grains, complex carbs, and low-sugar fruits and vegetables back into your regime, and also maintaining a high protein diet. Dieters should also continue to avoid processed foods and large amounts of sugar, to keep the weight off.

For Some People, the Keto Diet Is Just a Starting Point

Woman exercising with water bottle in the woods
Although exercise isn't imperative for keto results, it's an important aspect of healthy living.
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Chrissy Barth says keto might not be a great long-term diet plan, but it could be a good starting place for someone just starting out on their weight loss journey.

The keto diet might not be realistic for many people but might be helpful as a jump-start for weight loss. Sticking to a keto diet for a long time worries some. Any strict diet is tough to keep up with. When transitioning back to eating more of a balanced diet, the weight usually comes back especially when people do not take a lifestyle approach to weight loss including changing habits and behaviors. For those people that want to lose weight and keep it off, it’s all about finding the right balance of nutrients for them and their body.

Chrissy Barth, MS, RDN

Related: Dr. Eric Berg: If Keto Hasn’t Worked For You’ll, You Want To Try *This* For Easy Weight Loss

The Keto Diet’s Long-term Results Are Widely Debated

Woman grocery shopping with headphones stops to read ingredient label
Reading ingredient labels is a large part of adhering to any diet, including keto.
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In addition to some long term risks, some dieticians believe keto isn't a long-term answer to weight issues: "Weight loss hinges on a calorie deficit being in place. What makes a diet more or less effective in achieving weight loss is the ability of one to maintain the diet and remain in a calorie deficit," Megan Lee explains.

Restrictive diets themselves tend to be inherently unsustainable by nature

That's why, she adds, restrictive diets themselves tend to be inherently unsustainable by nature.: "The human body houses intricate weight-regulation mechanisms that fight against weight loss in an attempt to promote survival," she says. "Dieting has been found to be a consistent predictor of weight gain, making all diets ineffective for long term weight loss."

Keto Diet Success Depends on Preparation

  • Meal prep is a great way to stay on track

  • Meal prep is especially important when travelling

  • Carrying keto-friendly snacks whenever you’re out is a great way to stay on track

If taking the time to cook and prepare keto-friendly snacks sounds like too much of a time suck, this diet might not be for you, Stephanie Graziano said.

“Maintenance of the ketogenic eating pattern really demands a lot of meal planning especially when you will be traveling or away from home for any length of time,” added Rachel.

But, in addition to meal prep, she emphasizes that support is crucial.

Having keto-friendly snacks on hand in your bag and looking ahead at menus when you will be dining out may be helpful. Using an app to track what you are eating and having urine ketone test strips to check your levels can ensure you are eating the appropriate foods and amounts.

Stephanie Graziano, RD, CDN, CDCES

The Keto Diet Can Be a Viable Short-term Solution

Person gets their blood pressure measured
The keto diet can help lower blood pressure, long-term
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Anyone looking to start their weight loss journey might want to consider the keto diet as a starting point. The low-carbohydrate, high fat diet burns off water weight relatively quickly, making it a quick fix for those looking to lose a few pounds in a short amount of time.

Additionally, studies have shown success in using the diet to lower cholesterol and blood pressure. But based on expert opinions, it may not be great long-term, for the sake of weight loss and physical health. It is also quite costly, and limiting for those with allergies, restrictions, and aversions — making it inaccessible for certain people.

FAQs

How long does it typically take to lose weight on the keto diet?

For many, the first week on the diet often results in significant weight loss, because the dieter is shedding water weight. But the rate at which one loses weight depends on body type, and how closely the dieter adheres to the diet.

How long does it take to enter ketosis?

For some, it can take as little as three days to enter ketosis, which means the body is relying on fat, rather than carbohydrate storages, for energy. With ketosis, dieters may feel symptoms of headaches, indigestion, dizziness, or moodiness.

How long should someone stay on the keto diet?

Dieters should definitely speak to their doctors to determine how long they should follow the keto diet. Some follow the regimen for a few weeks, while others may stick with it for up to 12 months.

This content is not a substitute for professional medical advice or diagnosis. Always consult your physician before pursuing any treatment plan.