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ASK THE NUTRITIONIST: Is a plant-based diet the best choice?

In this week's column, Nonie De Long continues her series on the top 10 nutrition questions with a look a diet that's a growing trend

Dear readers, this week’s column features the sixth of the top 10 nutrition questions I get asked. Tune in over the following weeks for the remainder, and see the related content at the bottom this page for the previous columns. 

This week we’re going to look at the trend toward a plant-based diet and whether that’s actually good for our health.

The Plant-Based Trend

A plant-based diet has gained momentum as a health trend for a couple of reasons:

  • It’s promoted as more ethical
  • It’s promoted as more sustainable
  • It’s promoted as more healthy

So let’s look at these in turn.


The choice to avoid animal flesh as an ethical issue is, to me, religious in nature. Some people find it disturbing to think of consuming another living creature for sustenance and that fuels their move to a plant-based diet. It’s an expression of compassion and love for creation and also, I think, an attempt at responsible stewardship.

This is a very personal decision and it’s not really about health. It’s about a conviction that humans shouldn’t eat other animals because we can now survive without doing so. Because this is more about one’s religious beliefs than health, I don’t debate it. Everyone is entitled to their religious beliefs.

I do, however, support learning how to maintain optimal health when opting for this lifestyle and therefore highly caution parents around letting children and teens make this decision without professional nutritional coaching to ensure they get all the nutrients needed for proper brain and body development.


The idea that a plant-based diet is more sustainable than an omnivore diet that contains meat is based on a lot of slick marketing, but is actually a lot more complex than cow farts vs. green goodness.

Measuring carbon emissions is only one factor in assessing the real impacts of any human activity. Converting vast swaths of land into the crops that are popular in vegetarian and vegan diets often involves mass clear cutting and mono-cropping, both of which have been shown to be extremely destructive and unsustainable.

Topsoil is lost, animals are displaced, natural habitats are destroyed, water systems are disrupted, and soil fertility and resiliency declines. The land, water, (and food) are poisoned with pesticides and herbicides unless it’s grown organically and sustainably and these comprise a very small portion of all crops grown. In turn, these poisons impact all animals that drink from the water table and all insects in the area, as we are seeing with pollinators and the ever increasing rates of human cancers.

Additionally, the foods that are produced from these crops are often heavily processed in factories - like soy products, corn and wheat products, and vegetable oils.

We have been conditioned to believe that plant-based foods are the solution to our environmental issues. Perhaps surprisingly, some scientists are studying how livestock animals can play an important role in reversing environmental damage and desertification.


There is no doubt that eating less processed foods is good for our health. And eating more veggies is usually good for us, too. However, plant-based is not always as healthy as it’s promoted to be. It doesn’t necessarily equal less processed.

Watch this video to see how much processing is involved in creating canola oil. Watch this video to see what’s involved in creating commercial butter. This one shows how to make homemade butter. And this is how traditional olive oil is made. I share these to demonstrate something that isn’t self evident: plant-based is not always healthier OR more natural. It can be. But it isn’t always.

Consider this:

  • Fruit loops and fruit roll-ups are plant-based.
  • Chips and chocolate bars can be plant-based.
  • Beer and veggie pizza are plant-based.
  • White bread and chocolate cake can be plant-based.

It would be silly to think these foods do anything to improve our health.

Now, let’s consider some whole, plant-based foods.

Sweet potatoes are plant-based. One cup of sweet potato contains 27g of carbs. It contains only 2.1g of protein. One cup of quinoa contains 39g of carbs and only 8g of protein. One banana contains 27g carbs and only 1.3g protein.

Do you see the problem here? In terms of our metabolic health, these “healthy plant-based foods” are largely composed of carbs. Carbs in the mouth are all converted into sugars in the body. Given that insulin resistance is the number one health crisis today, affecting at least 50% of the adult population in some form or other, this is a grave concern.

How do you know if you’re insulin resistant? Well, it often happens years before we’re diagnosed diabetic. There is a simple test, though. The easiest way to measure is taking our waist to hip ratio. Measure the waist (around the belly button). Now measure the hips (around the largest part of the bum). If the waist is larger than the hips, you’re insulin resistant and on your way to type two diabetes, if not there already.

Nothing costs our healthcare system more or damages overall health more than insulin resistance. It fuels cancer. It fuels heart disease. It fuels mental health issues. It fuels dementia. It fuels inflammatory and auto-immune conditions.

It stands to reason then, that this one health issue is of particular concern when determining the health of food products. This is why seemingly healthy whole foods like fruit, which are plant-based, can be damaging in excess. They are high in fructose, which has been shown to be at least as bad as glucose for causing insulin resistance.

Conversely, meat, poultry, fish, seafood, eggs, high fat dairy, and insect food products are very protein and nutrient dense with little to no carbs to speak of. They create healthy muscle tissue and healthy neurotransmitters. They create healthy bones and teeth. They fuel enzymatic reactions in the body. Almost every bit of them is used for building something or breaking something down inside the body.

Carbs (sugar) on the other hand, are used only for energy and creating fat stores. Any more than 30-50g per day is enough to instigate the beginnings of insulin resistance in sedentary adults. That’s all it takes to make us fat, sick, and addicted.

So when it comes to plant-based foods, I can’t say as a food group that they are healthier. Vegetables I endorse whole-heartedly, unless you have an autoimmune condition or leaky gut, in which case they may be provoking your symptoms. But this is the exception, not the norm.

However, processed plant-based foods I do not endorse. Processed foods are treats, not foods, whole grain bread and rice included.

Fruit is a bit more complex. It’s case specific. If you’re overweight or don’t pass the waist-hip test then no, I don’t recommend it. If you’re athletic and slim I think it’s fine after a meal or with something to slow digestion like a handful of nuts or seeds or a piece of natural cheese or some unsweetened yogurt. Then it does not spike the blood sugar and stimulate the same insulin response. In this case, fruit is healthy. Can you see the difference?

I realize this may not be the nutrition information you’re used to seeing, but if that’s the case I invite you to ask where conventional nutrition advice has gotten us. Look around.

Are people in better health than they were 50 years ago? Do children and young adults look better or worse? Are we experiencing fewer chronic health conditions or more as we age? How many people had diabetes back then? How many had mental health issues and Alzheimer’s? (Both metabolic issues linked to insulin resistance, by the way.) Are we really getting information that’s helping us?

In terms of health I think the question isn’t whether or not the food comes from a plant, but the nutrients it contains. How nutrient dense is it?

Look at the ratio of carbs and proteins. Look at the quality of the fat in it, if any. Look at the minerals and vitamins it contains. Certainly look at how processed it is. Does it come directly from a farm or does it need to be crushed or milled and ground and processed first? In my opinion, these tell us much more about the health of food than if it’s plant-based. And using this metric, I have to recommend more (naturally raised) meat and seafood, not more grains, for health.

I hope this is helpful. As always, if you have your own nutrition related question, send me an email at [email protected]. If you’d like to read more articles like this, you can find me at


Nonie Nutritionista