A Dietitian’s Review of Whole Food Plant-Based, No Oil (WFPBNO)

February 16, 2022

The whole food plant-based, no oil diet has attracted some controversy.

The term ‘whole food plant-based’ is pretty much what it sounds like. It is a diet based on whole foods that limits/excludes animal products and processed foods.

Whole food plant-based, no oil (WFPBNO) takes this a couple of steps further.

It follows that initial food philosophy with the addition of excluding oils and eating other minimally processed and higher fat foods in moderation.

Foods to include and avoid on a whole food plant-based, no oil diet

Foods that you can eat freely

Fruit
Vegetables
Unprocessed wholegrains
Legumes

Foods that you can eat in moderation

Nuts
Seeds
Coconut
Avocado
Minimally processed soy products such as tofu and tempeh
Dried fruit
Added sweeteners (‘non-refined’) such as maple syrup

Foods that you avoid

Meat
Dairy
Poultry
Seafood
Oils and products containing oil
Processed grains
Refined sugars
Fruit juice
Anything else not listed above

Why are foods grouped like this?

Basically, foods are ranked or grouped based on their calorie density.

Calorie density refers to how many calories are in a food product in relation to its volume.

For example, 1 cup of mango has roughly the same amount of calories as 1 tbsp of olive oil. In this case, the mango has a much lower calorie density.

That is because the mango is made up of water, fibre and carbohydrates. Whilst the olive oil is almost exclusively made of fat.

Fat is also the most calorie-dense macronutrient.

Protein and carbohydrates contain roughly 4 calories per gram, whilst fat contains 9 calories per gram.

So gram for gram, fat provides more calories.

The only reason foods such as nuts, seeds and avocado are included in moderation is because they are considered ‘healthy foods’, in that they do provide a range of vitamins and minerals required by the human body, despite being more calorie-dense options.

Calorie density & weight loss

The idea that focusing on high volume, low-calorie foods for weight loss is not new.

Outside of the veganism and plant-based world, this is simply called volume eating.

Including a significant amount of high fibre and high volume foods that provide few calories can allow someone to feel full and satisfied despite reducing their calorie intake.

For weight loss to occur, you need to be in a calorie deficit.

This means eating less calories than what your body is burning. The body will then be forced to use its internal energy stores (fat & muscle) as a fuel source to make up for the energy deficit.

Over time this results in weight loss.

Volume eating makes maintaining a calorie deficit easier. For many, volume eating allows them to be in a calorie deficit without calorie counting.

The WFPBNO diet is simply a way to incorporate volume eating, albeit, a pretty extreme way to do it.

The whole food plant-based, no oil diet & weight loss

The WFPBNO diet is a diet created for weight loss and research has shown that it is actually quite effective.

The Broad Study from New Zealand, published in 2017, was a randomised control trial designed to investigate the effect of a whole food plant-based diet on weight and markers of chronic disease (1).

The study included 65 participants aged 35-70 that were diagnosed with obesity or were overweight and had at least one of the following: heart disease, type 2 diabetes, hypertension or high cholesterol.

Thirty-two participants received standard care as per current medical guidelines in New Zealand and the other 33 were put on a non-energy-restricted WFPB diet with vitamin B12 supplementation.

Researchers summarised their invention diet:

“We encouraged starches such as potatoes, sweet potato, bread, cereals and pasta to satisfy the appetite. Participants were asked to avoid refined oils (e.g. olive or coconut oil) and animal products (meat, fish, eggs and dairy products). We discouraged high-fat plant foods such as nuts and avocados, and highly processed foods. We encouraged participants to minimise sugar, salt and caffeinated beverages. We provided 50 μg daily vitamin B12 (methylcobalamin) supplements.”

Overall, the diet provided around 7-15% of calories from fat with a huge focus on plant-based, volume eating. So this is the WFPBNO diet in a nutshell.

Interestingly, at the 6-month follow-up, weight loss was much greater amongst the group that followed the WFPBNO diet versus the standard care group.

In fact, the intervention group lost on average almost 12kgs after 6 months, whilst the control group lost less than 3kgs on average.

Although the WFPBNO group would have definitely also benefited from the twice-weekly meetings, cooking classes, nutrition education sessions and other support they received in comparison to the other group, the diet would still have had something to do with these very clear results.

The study at least tells us that when the WFPBNO diet is implemented with support, it works for weight loss.

And honestly, it works quite well.

The issue with extreme volume eating

So we have established that the WFPBNO approach can work for weight loss.

That doesn’t mean that it is not without its pitfalls.

WFPBNO is volume eating on steroids. When we are splitting hairs over the caloric density of beans versus tofu, we know we have probably gone too far.

1. It doesn’t reduce appetite during weight loss

If you are eating WFPBNO for weight loss, you will likely have to continue eating that way for the rest of your life to maintain your weight loss.

Typically, when dieting, food portions are reduced. Even if you are using some volume eating principles and incorporating healthy amounts of fruits and vegetables.

This means that as you diet and lose weight, your appetite will also decrease over time. Meaning that you will need less volume of food to feel satisfied.

However, if you are taking an extreme volume eating approach, where large portion sizes are maintained throughout, you won’t be able to dial back on the volume eating without feeling hungry.

Therefore, you are kind of stuck on a WFPBNO diet because you never addressed the appetite problem when dieting.

Think of competitive eaters. Did you know that competitive eaters use this same approach to practice for events?

They don’t want to be overconsuming calories all of the time, so they will practice increasing their ability to tolerate large volumes of food with high fibre, low calorie density plant foods!

2. It may cause gut issues

Consuming an excessive amount of low-calorie options could potentially lead to gastrointestinal symptoms.

Regular vegan diets are often already high in fibre. It is not uncommon for vegans to be consuming double the amount of fibre recommended for health and well-being. That is without having a focus on volume eating and moderate to high-fat foods.

So the amount of fibre you would be getting on a WFPBNO diet would likely be well above that even seen in a typical vegan diet.

A very high fibre intake is likely to result in bloating and flatulence as a minimum. Some people may experience constipation, diarrhoea and abdominal pain as well.

Not to mention that the main source of protein on a WFPBNO diet is legumes.

Legumes are very fibre-rich but they also contain a certain type of carbohydrate called oligosaccharides.

Oligosaccharides are part of the FODMAP family. They are fermentable carbohydrates that are poorly digested and can cause gastrointestinal distress in some people.

In manageable quantities, legumes may cause no symptoms or potentially just a little bit of gas for most people. In significant quantities, severe bloating, flatulence and abdominal pain is quite common.

This isn’t to say that WFPBNO is bad for gut health, it just may cause unpleasant gastrointestinal symptoms.

3. Dietary restriction & disordered eating

With any extreme diet (and whole food plant-based, no oil would be considered extreme because of how many rules and restrictions it imposes), there are going to be drawbacks.

One potential flaw in this system is that it may actually contribute to a worse relationship with food and potentially some disordered eating patterns.

There are many effective ways to lose weight, this includes starving yourself but most health professionals are not going to recommend that.

Obviously, that is a very extreme example but dietary restriction to this extent is not often a good thing for a healthy relationship with food.

In online WFPBNO forums and groups, there is often a lot of moralising food and shaming other people for their food choices.

Foods are considered either good or bad. There is very little room for nuance. No room for having certain foods just because you enjoy them.

For some people, this type of diet legitimises food avoidance that stems from a form of disordered eating.

We know that there is a link between those who take on a vegetarian/vegan diet and eating disorders. In one study of over 150 women, those with a history of disordered eating were 40% more likely to be vegetarian or vegan (2).

And as things get more restrictive, it is safe to bet that there may be even more of a link.

Our Clinic Specialises in Eating Disorder Recovery For People Following Vegan and Vegetarian Diets

Plant-based diets are great for health, better for the environment and for many is a lifestyle choice stemming from ethical motivations. However, significantly restricting food choices is not usually a sign of a healthy and stress-free relationship with food.

So whilst a plant-based diet rich in whole foods is a great approach to nutrition, further restricting beyond that can be a red flag.

The importance of fats in a healthy diet

Having adequate fat intake is important for many reasons including the absorption of fat-soluble vitamins A, D, E & K.

Omega 3 fats specifically have an important role in maintaining structural membrane lipids, particularly in nerve tissue and the retina.

A very low fat intake can lead to deficiency of fat soluble vitamins, rough scaly skin and dermatitis amongst other things.

The recommended daily intake for fat in adults is 15-35% of daily calorie intake. However, in the Broad study using a WFPBNO, participants were only receiving 7-15% of their calories from fats.

The difference in fat intake likely comes from how strictly participants were avoiding higher fat foods such as nuts, seeds and avocados.

Some participants likely had these foods regularly in small quantities, whilst others tried their best to avoid them as much as possible.

From a health perspective, those who are getting ~15% of calories from fat and often consuming small portions of nuts, seeds and avocado are probably eating enough to meet their body’s basic needs.

But those who are avoiding those healthy, higher fat foods more strictly are less likely to be meeting their minimum fat needs.

Excessive dietary fat intake has been linked to increased risk of obesity, coronary heart disease and certain types of cancer.

So aiming for a moderate fat intake with a focus on healthy fats is probably a good choice.

Just don’t take it so far in the other direction that you are not meeting your basic requirements for fat intake.

Meeting your nutrient requirements on a whole food plant-based, no oil diet

Protein

Protein requirements for vegans are around 10-20% above the recommendations for non-vegans. This comes out to be ~1g per kilogram body weight per day as a minimum for health and wellbeing.

Whilst that is not a great deal of protein, many vegans struggle to meet this minimum. Vegans who then exclude or limit soy foods, nuts and seeds are likely to struggle even more.

Legumes are amazing. Protein and nutrient-packed powerhouses. But as someone’s main protein source, they can provide lackluster results.

To put this into context a 70kg person would require at least 70g of protein daily. In comparison, legumes contain 15-20g per standard 400g can.

Not too many people would be eating a full can of legumes daily, let alone 2-3 cans.

You would be eating some protein from whole grains and other foods, although it is likely not going to be a significant portion of your daily requirements. You will still need to eat a huge amount of legumes to meet your needs.

Nonetheless, vegan athletes and those interested in muscle building require anywhere between 1.8-2.2g of protein per kilogram body weight. That would be impossible to achieve on a diet that limits efficient sources of protein such as tofu, textured vegetable protein and seitan.

Calcium

Calcium is the most abundant mineral in the human body with 98% found in the bones, 1% in teeth, and 1% in other tissues. As well as building and maintaining strong bones, calcium is needed for muscle contraction, nerve function and blood clotting.

If you don’t get enough calcium from your diet for these functions, calcium will be drawn from your bones, which over time can lead to thinning of the bones, known as osteoporosis.

The best sources of calcium on a vegan diet are calcium-fortified plant milks and calcium set tofu.

These two foods provide a significant amount of calcium per standard serving size and are also well absorbed in the body.

However, both of these are limited on a WFPBNO diet.

There are a few other good sources of calcium on a vegan diet including sesame seeds, tahini, almonds and dark green vegetables.

Once again, 3 out of 4 of these foods are limited as part of a WFPBNO diet. Leaving you with only one option. Dark green vegetables.

For most adults, the recommended daily intake for calcium is 1000mg and 1 cup of cooked greens (asian greens, kale, broccoli etc) contains 150-200mg of calcium. Therefore, you would need to consume 4+ cups of cooked greens per day just to come close to the calcium recommendations.

On the other hand, if you weren’t excluding a wide range of calcium-rich foods you may have a cup of fortified milk with breakfast, a serving of tofu with lunch, tahini on crackers for a snack and some cooked greens with dinner.

Having access to a variety of calcium-rich foods makes the idea of getting enough calcium daily much less daunting and repetitive.

Iron

Iron is an essential mineral that is required by the body for a number of functions including transporting oxygen around the body.

Adequate iron consumption on a WFPBNO diet faces a similar problem to protein. Your main source will likely be legumes.

Other great sources of iron on a vegan diet would typically include fortified cereals and soy foods such as tofu, tempeh and textured vegetable protein.

But without those other great foods, you will be relying mostly on legumes.

Again for context, there is about 4-6mg of iron in a cup of cooked legumes. So let’s compare that to the recommended daily intake (RDI).

Those who don’t consume animal products actually have an iron RDI that is almost double (180%) that of the non-vegan RDI. That is because plant-based foods contain a type of iron called non-heme iron that is not as well absorbed by the body. Meaning you simply need more in your daily diet.

For non-menstruating individuals this translates to an RDI of 14mg per day, whilst people who menstruate need a whopping 32mg a day.

So for those who have a period, the idea of getting 32 mg of iron per day on a vegan diet can already be a tricky game to play. Let alone reducing your good sources of iron just to legumes alone!

It may be doable for those who do not menstruate, but again, 2+ cups of cooked legumes is a lot of food to eat daily.

Zinc

Zinc is found in every part of our body and has a wide range of functions. It is important for: growth and development, reproduction, vitamin A metabolism, night vision, appetite, taste sensation, a strong immune system, healthy skin, wound healing, and hormone interactions.

The best sources of zinc on a plant-based diet are nuts, seeds and soy foods. With tofu, sunflower seeds, pumpkin seeds, cashews and almonds being some of the best sources.

All of these foods are limited on a WFPBNO diet and zinc would be an extremely difficult nutrient to get enough of.

Not to mention that like iron, plant-based sources of zinc are also less bioavailable and you need 150% of the regular RDI on a vegan diet versus a non-vegan diet.

You will get some zinc from different kinds of legumes, vegetables and wholegrains but it is highly unlikely that it will be enough to meet daily requirements, particularly for men.

Omega-3

Omega-3 fatty acids play an important role in good health.

They are important in maintaining cell membranes, are required for brain and eye development, help regulate metabolism, reduce inflammation, blood pressure and cholesterol and may protect against heart disease. Omega-3 fatty acids are particularly important during pregnancy and breastfeeding.

Rich sources of omega 3 on a plant based diet include chia seeds, flaxseeds/linseeds and walnuts. One to two tablespoons of these foods daily can meet your omega-3 requirements for most people.

But once again, nuts and seeds are limited on a WFPBNO diet and sources of omega 3 fatty acids are not included daily. Therefore as you would expect on any very low fat diet, the WFPBNO diet does not provide adequate omega 3 fatty acids.

Are plant-based oils bad for us?

Supporters of the whole food, plant-based no oil lifestyle have a very strong stance against oil. Even oils that contain predominately healthy fats such as olive oil.

They claim that vegetable oils are energy-dense and nutrient-poor.

When we are comparing the nutrient density versus calorie density of oils, this claim does check out.

Vegetable oil doesn’t contain many micronutrients in comparison to the calories it provides.

Due to its caloric density, overconsumption of vegetable oils may also cause someone to eat too many calories and lead to weight gain in the long term.

But there is a large grey area in between having no oil in your diet and eating too much. It doesn’t have to be a black-and-white solution.

If weight loss or weight management is your goal, it is completely reasonable to limit oil in your diet. If you have a similar relationship to the olive oil bottle as Jamie Oliver, it could be worthwhile dialing back.

On the other hand, you can have a small drizzle of olive oil on your roasted potatoes to make them crunchy or a plant milk with a small amount of added oil for improved mouthfeel.

Summary & Final Thoughts

The whole food plant-based, no oil community does not have the completely wrong idea. The basic philosophy of focusing on high volume, low-calorie foods for weight loss is actually really helpful.

High volume, low-energy density foods that are high in fibre keep us full despite being lower in calories than other foods. This makes it easier to reduce our overall calorie intake, maintain a calorie deficit and lose weight over time.

However, this concept can be taken too far. Demonising foods solely based on their calorie density is not helpful. There are a lot of healthy foods that have higher energy densities such as nuts and seeds. There are also many minimally processed foods that are excellent sources of vitamins and minerals such as tofu, textured vegetable protein, fortified cereals and fortified plant milks.

By limiting these foods, you are making it harder to meet your daily requirements for certain nutrients and likely being unnecessarily restrictive.

But it is clear that the whole food plant-based, no oil community has a spectrum of what they consider moderation. For many, ‘in moderation’ can mean daily intake in small portions compared to other foods.

It makes sense to have small portions of high-calorie foods and larger portions of low-calorie foods if you want to lose weight. Just do so within reason, where you are not limiting your ability to meet your body’s nutrient requirements.

Completely avoiding all ‘fun foods’ is also not beneficial to a person’s relationship with food. It is completely reasonable to eat foods just because you enjoy them sometimes.

As for the complete exclusion of oil. You probably won’t be doing yourself any harm by excluding oils from your diet but it’s also not as beneficial as some would make it out to be. Nutrition is nuanced and any dietary pattern that labels foods ‘good’ or ‘bad’ is probably oversimplifying things.

Oil is very calorie-dense so if weight management is important to you, it is likely best not to go ‘full Jamie Oliver’ with the olive oil bottle but the small amount of oil added to your almond milk isn’t going to harm you in any way.