- REUTERS/Henry Romero
- The ketogenic diet and Paleolithic diet both restrict whole grains and legumes, but the two have key differences.
- The paleo diet focuses on leaner proteins and cuts most dairy products.
- The keto diet encourages fattier proteins and cuts high-carb foods, including some vegetables.
The much-hyped diets have a few things in common – they restrict the consumption of whole grains and legumes, for one – but they have key factors that set them apart.
INSIDER spoke with registered dietitian nutritionists LeeAnn Weintraub and Amy Gorin as well as “Mom Hacks” author Dr. Darria Gillespie about the differences between keto and paleo and the benefits and problems with each diet.
The diets have different intentions
The paleo diet aims to follow the back-to-basics eating principles of cave people and encourages lean meats, fresh fruits and vegetables, and nuts while eliminating many whole grains, processed foods and sugars, and most dairy products.
The keto diet focuses on helping your body burn fat instead of glucose by significantly restricting your carb intake and forcing your body into a state of ketosis.
Both diets encourage cutting carbs, and while doing so can lead to weight loss, some experts warn against it.
Studies have shown that cutting out entire food groups can be detrimental to your health. An August 2018 study of almost 450,000 participants found that people who consumed carbs as at least half of their daily intake tended to live longer than those who ate less than that. The study’s authors posited that this could be because people who cut out carbs cut out many mineral- and fiber-rich fruits and vegetables in favor of proteins and animal fats. Vegetables and fruits like carrots, green peas, and mangoes are high in carbs, making them something to avoid on the keto diet.
“Whole grains are something that have been shown to reduce mortality,” Gillespie told INSIDER. “I think that any diet that cuts out legumes and whole grains – many which have been shown to be an excellent source of protein and contain many beneficial nutrients – is too restrictive.”
You can eat more carbs on paleo, and fat is more important on keto
People on the paleo diets are welcome to eat as many carb-rich fruits as they want, including sweet potatoes, corn, squash, apples, and bananas. Meanwhile, eating just one apple, which has about 25 grams of carbs, on the keto diet could take you out of ketosis, as many keto participants try to consume about 30 grams of carbs a day.
Gillespie recalled being in medical school and trying the keto diet. “I remember by day three, seeing a buddy of mine who was not on the keto diet – he was eating an apple, and I was viscerally jealous of him because I wanted that apple so badly,” she said. “When you’re on the keto diet, you’re eating protein and you’re eating fat, and you can only eat so many fruits and vegetables, as they tend to be high in carbs and can get you out of ketosis.”
Both diets favor healthy fats. Gillespie said, “When it comes to oils, they tend to be ‘good fat,’ as they’re usually from nuts and seeds or from fatty fish, which is omega-3.”
While “lean proteins like chicken breast are acceptable in paleo, its low-fat content makes it incompatible with keto,” Weintraub told INSIDER. Considering that followers of the keto diet are aiming to get about 80% of their daily caloric intake from fat, fattier cuts of meat like steak, pork belly, and bacon are fair game. Processed meats like hot dogs and sausage can also be part of the keto diet.
“That’s the main problem with the keto diet,” Gillespie said. “You’re eating very high amounts of saturated fat and you’re not eating those things that we know are beneficial for health, like produce, whole grains, and legumes.”
Because hunter-gatherers didn’t milk animals, people on the paleo diet often don’t eat dairy, though some make an exception for butter. On the other hand, keto participants can consume certain low-carb hard cheeses, including blue cheese, Gouda, and Parmesan, and some full-fat dairy options, including sour cream, grass-fed butter, ghee (clarified butter), and heavy whipping cream, according to Perfect Keto.
The keto diet requires you to count your macros to ensure your body is constantly in a state of ketosis
- Melia Robinson/Business Insider
If constantly keeping track of your caloric intake is a deal-breaker, the keto diet might not be for you. Because the diet works by forcing your body into ketosis, it’s essential that you count your macronutrients – the main nutrients your body needs – to make sure you’re consuming the right amounts.
Gorin said: “Keep in mind that there are no cheat days. Once you send your body into ketosis, you need to consistently follow the keto diet to keep your body in ketosis. This amount of inflexibility does not work for many people.”
Because the diet is so restrictive, it can be difficult to follow for a long amount of time.
“I think many health experts would agree that the ketogenic diet is a clinical diet with roots in treating epilepsy and is quite extreme for long-term use when not medically indicated,” Weintraub said. “It restricts major food groups including most fruit, starchy vegetables, grains and beans, and, of course, sugar and other sweeteners. This likely results in a low fiber intake.”
The paleo diet acts as more of a guideline to help you make decisions about nutrition
“The problem with trying to recreate what our ancestors ate is we don’t know entirely what they ate,” Gillespie said. “The current branded paleo diet tends to lack legumes and whole grains, and it’s probably a far cry from what our ancestors ate. They probably did have a diet low in saturated fat, but they took in over 50% of their calories from produce and probably had up to 100 grams of fiber a day, which is a ton.”
While the paleo diet can be done healthfully as long as you’re consuming enough vegetables and fruits, it can be difficult to get the fiber you need if you completely cut out legumes and whole grains.
“Pulses [chickpeas, lentils, beans, and dried peas] are not part of the paleo eating plan, and for the keto diet they are often pushed aside because of their carbohydrate content,” Gorin said. “These foods are a good source of filling protein and an excellent source of fiber, which also helps to satiate you and can help keep your digestion healthy.”
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- Spain was just ranked the healthiest country in the world, and the Mediterranean diet could have played a role
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