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Paleo and Atkins Diets: Low-Carb for Different Reasons

There are a lots of low-carb weight loss diets out there, but the two most popular may be paleo and Atkins diets. The Atkins diet, which first popularized the low-carb movement, is divided into four phases: The first two largely focus on eliminating carbohydrates, before gradually introducing them back in. And the paleo diet eats only what its creators think hunter-gatherers could access in the Stone Age, eliminating ingredients obtained from modern farming, such as wheat, legumes, soy and more.

Woman’s World spoke with Christine Byrne, MPH, RD, of Ruby Oak Nutrition in Raleigh, North Carolina, who says the main difference is that Atkins is explicitly low-carb, while paleo still includes starchy fruits and veggies: “Atkins is explicitly a low-carb, high-fat, high-protein diet, and the goal of the diet is to push your body into ketosis, a state where it burns fat for energy instead of glucose (AKA carbs),” she explains.

The paleo diet focuses on fruits, vegetables, meat, fish, eggs, nuts and seeds; and eliminates grains, added sugar, legumes, and processed foods. Most people who follow a paleo diet probably aren’t in ketosis, since the diet includes carb-rich (and also nutrient-dense!) foods like fruits and starchy vegetables.

Christine Byrne

Paleo and Atkins Diets: A Side-By-Side of Both Low-Carb Plans

Woman reaching into fridge for fresh vegetable
Atkins and Paleo both emphasize the importance of low-starch produce and protein.Getty
Permitted FoodsMeats; fish; eggs, low-carb vegetables; full-fat dairy; nuts and seeds; whole grains (during phases three and four)Fruits; vegetables; nuts and seeds; eggs; lean meats; fish; fruit and nut oils such as olive and coconut oil
Restricted FoodsCarbohydrates during first two phases; refined sugars and oils; alcohol; legumes, fruits, and starchy vegetables during phase oneRefined carbohydrates; legumes; dairy; processed oils and sugars; alcohol; artificial sweeteners and processed foods
Caloric Restrictions1,500 to 1,800 for women; 1,800 to 2,200 for menNone
Short-Term EffectivenessEffective for short-term weight loss, particularly in the early stagesSometimes significant, sometimes not at all
Long-Term EffectivenessCan help with weight loss long-term before hitting a weight loss plateauSomewhat significant fat loss over 24 month period
Short-Term Side EffectsThe low-carb flu, which is similar to “keto flu” — side effects include: constipation, headaches, halitosis, weakness, fatigueSimilar to Atkins, many feel flu-like symptoms from lack of carbohydrates
Long-Term RisksLarge amounts of fat can contribute to heart disease, kidney issues and certain types of cancersPossible increase in LDL cholesterol, risk of heart problems and less bone density
Cheat DaysOne “cheat meal” per week is permittedOne cheat day every one to two weeks
Annual Cost$4,319 per year, according to FinderAbout $3,900 per week, according to PaleoPlan

The Atkins Diet Phases Out Carbs Before Eventually Phasing Them Back In

Bowl of salad next to salt and pepper shakers
Loading up on vegetables and protein are key to adhering to the Atkins diet.Getty

The Atkins diet is divided into four phases, which get progressively more flexible over time: it starts with Phase one, which limits carbohydrates, including starchy fruits and vegetables to 20 grams per day for about two weeks. It also eliminates processed oils, sugars, and alcohol. Phase Two brings back limited amounts of starchy fruits and vegetables, allowing for about 50 grams of carbohydrates. This lasts until the dieter has made it to at least 10 pounds until meeting their goal weight.

Phase Three allows for up to 80 grams of carbohydrates, allowing for starchy vegetables and whole grains until the person meets their goal weight. And finally, Phase Four allows for up to 100 grams of carbohydrates per day, encouraging healthy habits “for life.” During each phase, 30 minutes of daily exercise and eight glasses of water per day are highly encouraged.

Short-Term, Many See Weight Loss — Mostly in First Two Phases

Nutritionist weighs young woman on scale
The most results from Atkins tend to take place during the first two phases, or the first four weeks.Getty

The early stages of Atkins are generally when dieters see the most results. While this may be encouraging for some to continue the diet, many speculate that it’s due to the loss of water weight. According to Atkins Facts, the quick weight loss generally stems from removing carbohydrates from the diet.

“The diuretic effect of low carb diets can result in people losing a gallon of water in pounds the first week,” the article reads. “This precipitous early weight loss encourages dieters to continue the diet even though they have lost mostly water weight… If one wanted to try to lose water weight, sweating it away in a sauna may be a more healthful way.”

Some Experience Unpleasant Short-Term Side Effects

Short-term, many dieters adhering to the Atkins diet tend to experience the keto or low-carb flu, which results from lowering their carbohydrate intake. The Atkins brand lists a number of possible low-carb flu symptoms, including moodiness, constipation, headache, nausea, dizziness, sleep issues and brain fog.

o remedy these symptoms, Atkins recommends adding light movement to your day, consistently hydrating, increasing electrolytes and loading up on vegetables and healthy fats.

Studies Find Positive Long-Term Impacts From Atkins

Doctor listens to older woman's heart beat.
Weight loss with Atkins comes can boost heart health.Getty

The benefits that come with losing weight on diets such as Atkins come with long-term benefits. A Stanford study looked at the impacts of Atkins long-term (more than six months). And over the course of a year, found that participants not only lost weight — but also decreased their risk of hypertension, increased HDL (good) cholesterol and lowered blood sugar levels.

“After 12 months, women following the Atkins diet, relative to at least one of the other groups, had larger decreases in body mass index, triglycerides and blood pressure; their high-density lipoprotein, the good kind of cholesterol, increased more than the women on the other diets,” the results read.

Weight Loss May Slow Down, Long-Term

And while the initial weight loss may be fast, dieters often see a plateau after the first few weeks. A Healthline article explains this is due to the fact that people are mostly losing water weight.

“Many people lose a lot of weight in the first week on a low carb diet, but this is mostly water weight. Weight loss will slow down significantly after this initial phase,” says Healthline. “Also, losing weight is not the same as losing fat.

Long-Term, A High Fat, High Protein Diet May Also Cause Health Issues

Doctor listens to man's heart beat.
More fat and protein can also lead to cardiovascular issues.Getty

Despite the initial benefits, low-carb diets may be linked to a number of health issues in the long run. Neal Barnard, MD, explains via WebMD that people who adhere to the diet long-term can face colon cancer, kidney issues and osteoporosis

They aren’t designed to work on an oil slick of fat

“The reason for the health worries is in large part due to red meat,” he tells WebMD. “People who eat meat every day have three times greater risk of developing colon cancer. And then there is the problem of the kidneys. They aren’t designed to work on an oil slick of fat.”

Atkins May Be Difficult to Stick With

Atkins eliminates entire food groups, and restrictions come with disadvantages. Aside from the fact that such restriction can lead disordered eating habits and yo-yo dieting, Barbara Rolls, PhD, tells MedicineNet the carbs aren’t even what helps with weight loss: it’s calorie restriction.

You can lose weight on anything that helps you to eat less, but that doesn’t mean it’s good for you

“No one has shown, in any studies, that anything magical is going on with Atkins other than calorie restriction. The diet is very prescriptive, very restrictive, and limits half of the foods we normally eat,” Rolls tells MedicineNet. “In the end it’s not fat, it’s not protein, it’s not carbs, it’s calories. You can lose weight on anything that helps you to eat less, but that doesn’t mean it’s good for you.”

The Paleo or “Paleolithic” Diet Emulates Stone Age Eating Habits

Man picks apples in an orchard
Paleo only includes foods accessible by hunting and gathering.Getty

The point of paleo is to eliminate whatever hunter-gatherers couldn’t get — anything that has become a diet staple as the result of “modern farming.” While allowing for fruits, veggies, meats, fish, eggs, and oils derived from fruits or nuts, it restricts grains, processed sugars and oils, dairy and alcohol.

Short-Term, Some See Weight Loss Results

Similar to Atkins, dieters are likely to see some sort of weight loss in the first few weeks — and possibly even the first few months — of adhering to the paleo diet. This may mostly be due to water weight, but a National Library of Medicine study points out that over a few months, paleo dieters loss not only weight, but also reduced their BMI and fat stores.

The Low-Carb Flu May Also Strike in the First Week, Though It’s Less Likely

Sick woman drinks water on the couch in her apartment.
The low-carb flu is less likely on a paleo diet — just don’t cut out starches.Getty

An article from Paleo Leap warns dieters that early side effects may include flu-like symptoms. Similar to the keto or Atkins diets, lowering one’s carbohydrate intake can trigger symptoms such as dizziness, moodiness, fatigue, headaches, nausea, constipation and indigestion.

Increasing water and electrolyte intake, and eating more healthy fats, may help avoid this unpleasant ailment. Also, eliminating starchy fruits and veggies unnecessarily will also prevent the low-carb flu, because the goal isn’t to enter ketosis. So, making sure to eat a wide range of fruits and vegetables is incredibly important.

Some of the Long-Term Paleo Effects May Also Be Negative

Long-term, paleo isn’t necessarily the best diet option. UC Davis explains that such a high-fat, high-protein diet can lead to high cholesterol and heart disease. Low dairy intake may also trigger osteoporosis and bone fractures.

The Restrictiveness of Paleo May Also Cause Issues

Person weighs themself on a scale
Restrictive diets like paleo can lead to yo-yo dieting and restrictive eating habits.Getty

Because the diet is so restrictive, it can be very hard to stick to. This can make consistent weight loss difficult, and therefore, may lead to people yo-yo dieting. Such restrictions can also lead to disordered eating habits, so those with a history of eating disorders should speak to a professional before trying the diet.

Paleo and Atkins Diets Aren’t Cheap

Filling your pantry with processed foods may be less healthy, but it’s certainly financially cheaper than cutting them out. That said, opting for meat, less carbs and sugars, and more produce is going to be more expensive than the average American diet. For example, Atkins costs about 17 percent more than the average American diet. And meanwhile, adhering to the paleo diet would require a 9 percent increase in income for low-income shoppers. Lowering the cost on both diets is possible, however, by buying frozen over fresh, shopping seasonally and opting for cheaper proteins.

Paleo and Atkins Diets Are Both Restrictive — Though Paleo May Be More Nutrient-Dense

An older man buying groceries and talking on the phone
Paleo doesn’t eliminate all carbohydrates, making for a more nutrient-rich diet with more variations.Getty

Both paleo and Atkins diets are quite restrictive, with Atkins eliminating carbohydrates altogether, and paleo eliminating all “modern farming ingredients.” And although paleo inherently restricts grains, it doesn’t eliminate all carbohydrates, keeping more nutrient-dense fruits and vegetables in dieter’s regiments.

“When it comes to lifelong health, I don’t typically recommend Atkins or Paleo since both are very restrictive and difficult to follow long-term,” Christine Byrne admits. “While I do like the paleo diet’s emphasis on fresh fruits and vegetables, it’s possible to eat more of these whole foods without totally eliminating other foods.”

How long should someone stay on Phase One of the Atkins diet?

Phase One of the Atkins diet, which allows for 20 grams of carbohydrates per day, lasts for two weeks. However, dieters can stick to any phase as long as they would like.

What should be avoided on the Atkins diet?

In the first two phases, starchy vegetables such as potatoes, and high sugar fruits like mango, should be avoided. Every phase also restricts refined carbohydrates, refined sugars, and processed oils.

How many carbs are allowed on the Atkins diet?

Carbs are almost entirely phased out in Phase One of Atkins, with only 20 grams daily. Phase Two allows for 50 grams, Phase Three allows for 80 grams, and Phase Four allows for 100 grams.

What are the rules of the paleo diet?

The rules of the paleo diet are to avoid any foods popularized by modern farming. This includes grains, processed sugars, oils and alcohol. People are allowed to eat anything that was easily accessible by hunter-gatherers, including meats, fish, eggs, fruits, vegetables, fruit oils, nut oils and nuts.

Are there risks to the paleo diet?

The risks of paleo include increased cholesterol, which can lead to serious cardiovascular issues over time. A lack of calcium can also lead to brittle bones, and over time, fractures and even possibly osteoporosis. Consulting a doctor before trying any diet is absolutely necessary.

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

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