Comparing Three Popular Diet Trends: Paleo vs Keto vs Mediterranean

Comparing Three Popular Diet Trends: Paleo vs Keto vs Mediterranean
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If you’re looking to be the fittest you can be you’ve undoubtedly looked into the diets that are likely to support your goals. You’re interested in being lean, maintaining muscle, peak performance and blowing away your doctor every time at your yearly physical. Unless you really are a cave dweller, you have heard of the Paleo (or similarly named) diets before. If you follow biohackers and scientific diet research, you’ve heard of the Ketogenic diet. And, if you ever watch or read the news, you most certainly have heard of the Mediterranean diet.

Halibut over lentils
Halibut over lentils

Have you given any of them a try, maybe skimmed the surface or are considering which one might be best for you? When it comes to these three popular diets, Christopher Gardner, Ph.D. Professor of Medicine and Director of Nutrition Studies at Stanford University says, “the public health community should be open to these, and every other diet. We have an obesity epidemic that we haven’t been able to solve, and this goes hand in hand with a chronic disease epidemic that is crippling the health care system of the US.”

So let’s look at these three diet trends, two of which have reliable research to back them up. They all include a moderate to high amount of protein intake which Americans love (a topic Dr. Gardener will be lecturing on this week). They can each give you great results for losing weight and improving important biomarkers. The issue, as with any diet is, can you adhere to one of these long term?

Let’s start first with the newest of the trends – the Paleo diet - founded by Loren Cordain, Ph.D. and has branched off into a movement launching many other brands based on Dr. Cordain’s tenets of “eating foods you were designed to eat.” The belief is that when we switched from eating only foods we could hunt and gather, to an agricultural diet growing grains and drinking milk, we began our demise into a culture suffering from chronic illnesses like diabetes, cardiovascular disease and obesity. Therefore we should eat like our ancestors did before we started farming more than 10,000 years ago.

It’s a compelling platform, but unless you go the eccentric, bow-and-arrow, Ted Nugent-style of shopping for meat, or decide to move to New Guinea or Africa to study the life of tribal culture, you probably won’t be able to duplicate a truly Paleo diet. Our early human ancestors probably ate way more fruits and vegetables than we do now because getting meat every day was a bit more of a chore. Ever try to hunt and kill a bison then carve it up with a hand made tool? Talk about “Dirty Jobs.” Also, consider that the fruits and vegetables we have access to now are very different from the produce that grew wild back in the Paleolithic era. And, the meat we eat now isn’t exactly running wild and free. The food our Paleolithic ancestors ate had more nutrients like omega-3s, fiber, vitamins, minerals, and less saturated fat and salt. Plus, some recent findings suggest that ancient humans were eating grasses and grain at least 100+ thousand years ago, according to National Geographic, and, making flour too. It’s hard to deny those cravings we homosapiens have for bread and cereal!

Eating like a true caveman is probably not going to happen, however Paleo proponents subscribe to a diet that’s high in protein from meat, seafood and eggs. Fats, aside from that in meat, should come from healthy oils (olive, walnut, flaxseed, macadamia, avocado, coconut). Non-starchy veggies, fruits and nuts make up the rest of the diet. They avoid processed foods (aside from buying butchered meat and cooking it- both of which are technically “processes”), as well as refined sugar, legumes (including peanuts), potatoes, dairy, and cereal grains. Generally speaking, it is a low-carb lifestyle and is supposed to promote weight loss without counting calories as long as you stick only to foods that are allowed. The original book claims you can lose weight and prevent and treat heart disease, cancer, osteoporosis, metabolic syndrome, and many other illnesses by following this way of eating. As of today, there is very limited research and according to Dr. Gardner, the biggest problem in determining it’s efficacy is that “so many people who say that they are on the Paleo diet are doing it differently than one another therefore it’s difficult to really study what it means to be following it.” Reliable studies aside, the Paleo-style diet is still trending upwards.

Level of difficulty to adhere to long term: Moderate

Now let’s talk about a diet that has a substantial body of research, is more cutting edge and, highly controversial. The Ketogenic diet – the eating plan that enchants biohackers and is loathed by conventional dieticians – was first widely promoted in the 1980’s by Dr. Robert Atkins and it freaked many of us in the health industry out. Our diets should be mostly fat while carbs should be cut almost completely? Whaaaaaat the…? Well, studies do back up many of the positive benefits of the ketogenic, or what’s sometimes referred to now as the “Modifiied Atkins Diet”, including rapid weight loss, but it’s not without some risks.

The goal of a ketogenic diet, which is the strictest form of a low-carb diet, is to force the body into ketosis, which occurs when the body doesn’t consume enough carbohydrates and breaks down fat to use as energy instead. For that to happen, carb intake has to be around 20 – 30 grams a day. That is super low and not at all easy to do. Plus when your body is switching over from using carbs as it’s primary energy source to using fat, you feel like dirt for a few days at least. Headaches, fatigue, difficulty sleeping, brain fog and lethargy are just a few of the fun side effects you may experience until you’re fully in a state of ketosis. But devotees say once you are in it, you feel great.

Although it’s a difficult eating style to follow, the ketogenic diet has been shown in trials to significantly decrease body weight, lower total cholesterol, significantly increase high-density lipoprotein (HDL) and decrease both low-density lipoprotein (LDL) and triglycerides. Studies of varying length mostly show positive results like these, especially when compared to low-fat diets for weight loss. Overall most studies done on this diet, as well as low-carb diets in general, reveal positive outcomes. The ketogenic diet was originally designed to treat children with epilepsy and seizure disorders, but since has been quite successful in helping obese people lose weight (as do other low carb diets) and treat diabetes. Now, ketogenic diets are being tested as a cancer therapy.

But this diet is not without its detractors. Since the main emphasis is avoiding carbs which make up a huge part of the American diet, particularly in the form of sugar and white flour, Dr. Gardener says people start losing weight right away when they eliminate just those two things. And, if done in a ketogenic way, there is some water loss too, which isn’t true fat loss. “If this diet really was the solution, everyone would be on it and the obesity epidemic would be ended and reversed. Not so,” he adds, “the weight loss success has proved to be short lived.”

Obesity aside, other health professionals warn that not eating enough carbohydrates can lower your muscle building hormone and T3 thyroid hormone levels, increase cortisol levels (the stress hormone), contribute to muscle loss and prevent muscle gain, and mess with a woman’s delicate hormone balance. It may also negatively affect athletic performance as shown in a study on off-road cyclists, but the flip side from this small study on gymnasts, showed no loss in strength. Note that although the research so far suggests more positive than negative results, it’s still not for everyone and the side effects for many can be very uncomfortable.

Level of difficulty to adhere to long term: Hard

Lastly there’s the good ‘ol, not as sexy, Mediterranean diet. Tested and approved time after time as a healthy diet that promotes weight loss, lowers cholesterol, helps improve rheumatoid arthritis, and reduces the risk for developing Alzheimer’s disease, diabetes, and various types of cancer. Not a bad sales pitch! As for weight loss, a large 2-year study, comparing low-carb, low-fat and Mediterranean diets, researchers found similar results between the low-carb and Mediterranean diet participants. The low-fat diets showed the least amount of weight loss.

The Mediterranean diet is by far the least controversial diet in the health field and has been around the longest. Researchers became intrigued by this diet because adults living in regions bordering the Mediterranean Sea have the lowest rates of chronic diseases and longest life expectancies in the world.

The Mediterranean diet is based on meals containing plenty of fresh fruits, vegetables, whole grains (whole wheat bread, brown rice, quinoa and bulgur), olive oil, beans, nuts, legumes (lentils, dried peas and beans), seeds, herbs and spices. The lifestyle also includes daily exercise, sharing meals with others, and a deep appreciation for quality of life.

How to do it? The Harvard Medical School blog recommends following these guidelines:

  • Eat fish at least twice a week.
  • Eat moderate portions of cheese and yogurt daily to weekly.
  • Eat moderate portions of poultry and eggs every two days or weekly.
  • Eat red meat sparingly or limit to three-ounce portions.
  • Drink plenty of water each day, and drink wine in moderation—no more than one (5-ounce) glass a day for women, two glasses per day for men.

Level of difficulty to adhere to long term: Relatively Easy

The debate of which is the best diet has long fired up the health community and has done much to add to the confusion of people trying to get fitter, healthier or just lose weight. Dr. Gardener points out when it comes to these or any diet really, “all of them work for some people, short term. None of them work for all people.” When it comes to sustainable weight loss, no diet, he says, “that anyone has come up with so far, has worked for even 5% of the population…..long term.” In other words, when you go off a diet, the overwhelming majority of people gain the weight back. He says we need to stop discussing “best diet” and think about how to live healthier lifestyles for the rest of our lives.

If you’ve been successful (or not) at maintaining a long term diet change, please share your story below.

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