Home » Nutrition Wars: Is there such a thing as the best diet?

Nutrition Wars: Is there such a thing as the best diet?

Vegan, Paleo, Mediterranean, Carnivore, Keto, Plant-based, Flexitarian, etc. There’s a flood of different popular diets out there. Each one has a list of foods you should and shouldn’t eat. Each one also has a vocal group of followers saying their diet is the best. And many base their diets (rightly or wrongly) on what our ancestors ate. The debates become so heated they’re right up there with politics and religion.

But is there such thing as the ideal diet? Is one diet really better than any other? Or is it personal preference? And is there anything we can learn from what ancient humans truly ate?

is one diet better than another

Better in what way?

In order to know if one diet is better than another, we need to decide what better means. Does it mean better at preventing disease? Better for the environment? Or one that will make you live the longest? And the most common factor associated with any diet, is weight loss.

All of these outcomes are worthy of study. But when it comes to studying nutrition, it’s a messy process.

The most common method is the observational study. In these studies, people report their eating habits at a point in time and are followed for a number of years to see who develops disease or dies. However, these studies often don’t take into account changes in diet over the years. Plus, they use the unreliable method of self-report to determine food intake. Therefore, they only provide suggestions and not answers. Because of this, the nutrition debates can continue endlessly.

To truly determine which diet is the best, we need to do randomized studies. But these studies are incredibly expensive and hard to do. Only one diet has been studied to see its effect on preventing disease. This is the Mediterranean diet, a diet high in fruits and vegetables, with plant-based oils, fish and limited meat that reduced the chances of getting heart disease.

what is the best diet

Comparing Diets

Many studies have compared various risk factors. When low fat and low carbohydrate diets were compared both improved blood pressure and cholesterol levels compared to a general diet. Studies also suggest the Paleo diet reduces blood pressure and cholesterol too. But when compared to the Mediterranean diet, the Paleo diet was no different in improving blood sugar metabolism. Similar findings have been reported when the Keto diet was also compared to the Mediterranean diet. In addition, the Keto diet increased LDL-cholesterol.

But it’s weight loss where diets have been compared the most. Many of these studies don’t use popular diet names and instead adjust the amount of carbohydrates, fats and protein. For example, an early study randomized participants to diets of high and low carbohydrate, high fat, and high protein. After two years, there was no difference in the amount of weight loss. A later study comparing diets of low fat to low carbohydrate also found no difference. These studies demonstrate that when it comes to weight loss, it’s not as important what you eat, but how much you eat.

Few studies have compared plant and animal-based studies to each other. When vegan, vegetarian, pesco-vegetarian, semi-vegetarian and omnivorous diets were compared, the vegan diet resulted in twice as much weight loss after six months than the others.

However, what may work in a controlled research setting may not be the same as in the real-world. When a group of 20 adults were housed in a clinic and given free access to either a plant-based low-fat diet or a low-carbohydrate keto-type diet, the plant-based diet resulted in a greater reduction of calories, suggesting a plant-based diet may be more filling.

what did our ancestors eat

How Our Ancestors Ate

Often entering into the debate is how our ancestors ate. Advocates of Paleo or Carnivore diets often state our cavepeople ancestors ate meat for hundreds of thousands of years. And therefore, conclude humans are meant to eat meat. On the other side, plant-based advocates say we’ve descended from apes, whose diets are almost all plants.

But let’s not forget, the average lifespan of a caveperson ranged from 25 to 40 years. Less than half of what it is today. While there are many reasons for this shortened lifespan, one can’t ignore a lack of nutrition may be involved.

The earliest evidence of ancient humans eating meat comes from more than 2 million years ago. And it’s believed this meat was scavenged from dead animals. It wasn’t until 500,000 years ago the first evidence of hunting tools appeared, which were made of stone. While this opened the door to hunting, chasing down animals with primitive tools wasn’t that easy.

Hadza men on a rock with their bows and arrows
Hadza men on a rock with their bows and arrows by Katiekk

Hunter and Gatherer Communities of Today

Looking at the diets of the few remaining hunter and gatherer communities around the world can tell us a lot about what our ancestors ate. Apart from the Inuit, whose diet consists of almost exclusively of meat, most hunter-gatherer communities are more gatherer than hunter.

The Tsimane living in Bolivia have a diet with over 60% of calories from plants, with 30% from animals (predominantly fish). Similarly, the Hadza in Tanzania have a predominantly plant diet. And while both populations eat meat, their intake fluctuates as the hunting season changes. During the wet season in Tanzania, meat may comprise <15% of the Hadza diet. This is despite using equipment such as bows and arrows, and guns (Tsimane only). It’s likely to have been much harder for ancient humans to get meat using only stone tools.

These diets (and other aspects of their lifestyle) appear to ward of many diseases. The Tsimane have the lowest levels of heart disease in the world. And their brains exhibit slower ageing. The Hadza also have low levels of risk factors for heart disease.

In contrast, the Inuit have a high-fat diet consisting of almost entirely of meat (caribou, birds, marine mammals and fish). Traditionally, Inuit populations have been believed to have lower rates of diabetes and heart disease. What may be fine for Inuit people may not be fine for the rest of us. It’s believed a genetic adaptation in Greenland Inuit may help them process their high-fat diet. An adaptation that’s extremely rare in other populations.

is there really a best diet?

Is there really a best diet?

When 33 health and nutrition experts were asked to rate 24 different diets based on health, the Mediterranean diet came first. This was followed by other diets which were predominantly plant-based with fish as the main animal source. The Paleo and Keto diet were ranked 19th and 20th, respectively.

One thing common to all of these diets, is not what they have, but what they don’t have. None of these diets include the consumption of high and ultra-high processed foods. Making a switch from processed foods to less processed foods, is always a healthier choice. And keep in mind, for a diet pattern to work for you, it needs to be something that fits in with you life. Diets that are too restrictive are usually harder to maintain.

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10 responses to “Nutrition Wars: Is there such a thing as the best diet?”

  1. Roderick Huggins Avatar
    Roderick Huggins

    Really enjoyed this article. I had earlier this year read Brain Food Surprising Science of Eating for Cognitive Power: by Lisa Mosconi, PhD. It was a great read as well. As I have Afib I also have read other writings including Dr. Dean Ornish’s Undo and somewhat follow the advice but found the menu challenging to stick to.
    Thanks again.

    1. Thanks for the comment and glad you enjoyed it. I agree, the Ornish diet is tough for many to follow. It’s great if a person can, but not many people can. Keep healthy!

  2. Pat O’Connor Avatar
    Pat O’Connor

    Doctors whose patients consume the standard western diet see them only decline.

  3. Terrific read Scott. Makes it clear that what you don’t eat is more important in the long run, in our life, than what a diet includes.
    I’d like to know in the Mediterranean users how much of that is fruit compared to vegetables. Fruit used as a weight loss component and strategy is flawed IMHO.
    As you point out, our diets have changed over the years and may again depending on the source and the supply chain that brings food to us.
    Fascinating subject, thanks for doing the work for us.
    Cardiac rehab in the Comox Valley

    1. Exactly! Thanks Barb!
      The Mediterranean diet recommended >=3 servings of fruit per day, plus >=2 servings of veg and >=3 servings of legumes.

      1. Hello Barb and Scott, Angel J. Cuenca from Spain.

        I am a big lover of fruits and vegetables. Not as a diet strategy because I enjoy them!! I usually eat 5-6 pieces of fruit every day.(My wife and daugthers 3-4 pieces/day) The whole family take 4-5 days a week salad (vegetables) to accompany lunch and/or dinner. And 2-3 days we eat legumes (lentils, chickpeas and beans).

        Fruits, as we all know, have a lot of fructose (sugar) and calories. It is evident that, as you well say, the fruit used as a component and strategy to lose weight is defective due to fructose. But fruit is a healthy food despite the calories. Or is it not better to take the calories from the fruit than those from a sausage or an ultra-processed food?

        Any diet based on counting calories or only based on what we eat, or what we don’t eat, is useless if it is not accompanied by Physical Activity/NEAT (Non Exercise Activity Thermogenesis) or Physical Exercise or both.

        So, doing a maximal simplification exercise:

        1.-Eat as healthy, varied and not excessive amounts as you can.
        2.-Be as physically active as possible. It is not enough to do 4-5 weekly sessions of 30 minutes of HIIT, if the rest of the time you are sitting in the office at work, and also in your free time, you are sitting on the sofa watching TV.
        Here NEAT is just as important as HIIT or any other physical exercise you do.

        Kind regards Barb and Scott.

      2. Hi Angel

        This is a great plan for you and your family!

        Fruit, with all it’s nutrients, is a healthy choice. The only time I’ve seen a reason for someone to eat less fruit is in a person with type 2 diabetes and uncontrolled blood sugar. This person was eating five or more servings per day. But this was very rare. For most people, getting 2-3 servings per day is part of healthy eating.

        For weight loss, the research tends to show it’s more how much one eats rather than what. And as you mention, any weight loss plan should include activity.

        thanks for sharing the great advice!

  4. Excellent read, in my 20s thinness years,….50s bones, muscles, brain, eyesight, brain-gut-axis, body weight, blood pressure, cholesterol, glowing skin…..Mediterranean style diet I adhere to. I can consistently follow for life. I weaned myself off UPF in my 40s. Diet style will depend on why, what a person’s personal belief is, their goals.

    1. Glad you liked it and thanks for sharing. Keep up the great work!

  5. Excellent information, agree elimination of UPF is common amongst these diet styles. Also a restriction of some sort is required for body reduction ie, Calories consumed. Covering all of your nutrition needs for lifespan & healthspan. Personally Mediterranean & Mind diets I incorporate. A recent diet I heard of The Harvard diet I didn’t think the best as dairy was limited (? Osteopenia & Osteoporosis). 🤹‍♂️ juggling your diet, exercise, sleep, age need constant attention.

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