Philosophical Vegan Forum

Let's talk about eating ONLY fruit for a certain amount of time. Why on earth would anyone want to do this? I haven't done much research but I'm pretty sure most people can clearly tell that it's not a balanced diet. So, what do you think?

Two friends that I love DEARLY who are both vegan and two of the greatest people I know are eating only fruit for about a month. "Mono-meals" and "brain fog" are what I keep seeing them post. They're both really smart and I'm just unsure what made them think that this is healthy to do. Yes, I'm sure they could be eating worse but this doesn't seem sustainable for even a month. Why not incorporate healthy cooked foods and vegetables too? Note that one of my friends is doing this as a "detox." Unsure how to approach the situation or if I should just completely stay out of it. However, from what I do know, there really is no reason to just eat fruit

Ask your friend these three questions;

1. What “toxins” is this fruit diet supposed to clean you of?

2. How (specifically) does this fruit diet cleanse you of these toxins?

3. Is there any evidence to support this?


Chances are, they won’t be able to answer the first question. They may cite some random quack, but be skeptical of that person as well. Check their credentials and fact-check their claims. If what they’re saying seems to go against the majority of professionals in that field, they’re likely a charlatan motivated by their own interests.

If you don’t want to intrude too much, I’d advise them to consult with a registered dietitian before adopting such a restrictive diet. Fruits tend to be a poor source of calcium, iodine, iron, zinc, protein, and many more nutrients. Fruitarian diets can work for some, but they need to be carefully planned and followed. Something that a dietitian can help to design. That being said, I doubt any dietitian would see the need to cut out vegetables, legumes, beans, nuts, etc. unless they have some rare medical condition. I imagine this would be incredibly wasteful too.

As with many of the over-the-counter detox supplements and “cleanse” diet plans, be very skeptical. There’s little evidence any of these things remove “toxins” from the body. https://nccih.nih.gov/health/detoxes-cleanses

Some of the diet regimens are effective at helping you loose weight, like some fruit-based diets, but that’s to be expected when all of what you’re eating is not very calorically dense.


We should take great care to distance these extremely fringe diets as far from veganism as we can, in the exact same way that we should distance racism from veganism as far as we can. I suspect that occasionally, people suffering from diet-related obstacles (eating disorders, orthorexia, body image, insecurity etc.) seek solace in these fringe diets. They delude themselves, or are deluded by others, into thinking that veganism will somehow be a “cure” to their problems.

Moving forward, if you don’t want to outright tell your friend not to be stupid, I’d just warn them to consult a dietitian before making such a change. The dietitian will probably set them straight for you.

A diet consisting of just fruits and vegetables is probably going to be low in calories overall. Diets that are too low in calories, including those under 1,200 calories per day for women and those under 1,800 calories per day for men, can slow your metabolism and if followed long-term, can increase your risk for heart problems, osteoporosis and other health conditions. If you're interested in trying this type of diet to lose weight, keep in mind that a slower metabolism also makes weight loss more difficult. Not getting enough calories can also cause headaches, dizziness, fatigue, emotional issues and fainting.

invincibleIJIN wrote: ↑Mon Jun 18, 2018 5:57 amDiets that are too low in calories, including those under 1,200 calories per day for women and those under 1,800 calories per day for men, can slow your metabolism and if followed long-term, can increase your risk for heart problems, osteoporosis and other health conditions. If you're interested in trying this type of diet to lose weight, keep in mind that a slower metabolism also makes weight loss more difficult. Not getting enough calories can also cause headaches, dizziness, fatigue, emotional issues and fainting.

The "metabolic damage" thing is a myth. It could potentially lower your metabolism a tiny bit, but not enough to impede serious weight loss, and it will spring right back; long term reduction in metabolism isn't a thing.

Health problems typically come from inadequate nutrition (search calorie restriction with adequate nutrition). So, if you're going on a low calorie diet, you can do it and it can help with weigh loss, but you have to avoid low nutrient foods so you can get enough protein, vitamins, minerals, etc.
You'd need to base it around legumes and vegetables, mostly, and limit fruit (which are richer in calories than most nutrients).

That said, some people react to very low calorie diets with a binge, so it doesn't always work due to psychology.
Moderate calorie restriction over a long time (100 - 200 calories less than maintenance) is likely to be more effective long-term. Think the tortoise and hare story -- slow and steady is the best.

brimstoneSalad wrote: ↑Mon Jun 18, 2018 3:13 pm Health problems typically come from inadequate nutrition (search calorie restriction with adequate nutrition). So, if you're going on a low calorie diet, you can do it and it can help with weigh loss, but you have to avoid low nutrient foods so you can get enough protein, vitamins, minerals, etc.
You'd need to base it around legumes and vegetables, mostly, and limit fruit (which are richer in calories than most nutrients).

I agree, but there’s another important factor.

I imagine a strict fruitarian diet, or any diet consisting of excessive amounts of fructose, could overwhelm the liver (causing it convert fructose into fat) and put some people at risk of gaining weight. In addition, fructose does’t suppress appetite as effectively as glucose, and this can lead to overeating, further exacerbating weight issues. https://www.ncbi.nlm.nih.gov/pubmed/23280226

Fruit can be a double-edged sword. It’s low in calories, and high in some nutrients and anti-oxidants, but limiting your diet solely to fruits can lead to a decrease in overall nutrient intake, spurring excessive food cravings, and weight-gain (as a result of high-fructose intake).


I’d recommend to the OP’s friend to focus more on vegetables and low-carb, high-fiber fruits like berries and kiwis.

I think the concept of eating raw food as a detoxification process is problematic, because raw plants (and those involved in home canning) cause half of the food poisoning outbreaks, according to the Centers for Disease Control, and there is an ongoing one caused by raw melons lately. Eating too many fruit seeds can cause appendicitis, phytobezoars, and perforate bowels too. Generally it's safer to eat the more acidic fruits raw, without ingesting seeds. Frozen fruits are possibly prone to listeria or other contamination, like the vegetables, which have warnings on the package to cook them for this reason. Cooking food is more detoxifying, according to the recommendations for food safety, and the extra nutrients preserved by not doing so wouldn't prevent disease in the case of contaminated raw food. Otherwise I don't presume it impossible to sustain a well planned fruit diet for as long as any other, but maybe that would be impractical. Although fruit bats outlive cats and dogs and cows, so you never know, someone has to try it.

brimstoneSalad wrote: ↑Mon Jun 18, 2018 3:13 pm The "metabolic damage" thing is a myth. It could potentially lower your metabolism a tiny bit, but not enough to impede serious weight loss, and it will spring right back; long term reduction in metabolism isn't a thing.

Whether its "damage" or not depends how you interpret it but caloric restriction results in various metabolic changes. To what degree those changes persist after a phase of caloric restriction isn't well known. There are a variety of studies on this.

For weight-loss there is an issue here as well, caloric restriction will lower your metabolism significantly overtime because it will at the very least result in a reduction in muscle mass and total body mass. Neither will spring right back, that is especially true of muscle mass. The body builds new muscle reluctantly and it becomes more and more difficult to add muscle mass as you age. So a period of calorie restriction can result in a new lower metabolic set-point that can difficult to increase. This can result in an increased rate of weight-gain because the amount people eat is often a matter of habit and not hunger.

Looks like someone tried it long term, and fruitarianism is considered an eating disorder as a result (according to a medical abstract).

Severe ketoacidosis secondary to starvation in a frutarian patient:
The present paper presents the first clinical case of a patient suffering from Frutarianism a new "Eating disorder" and severe Ketoacidosis. The life-style feed strictly only on fruits (not even other vegetables, since plant death is necessary previous consumption).This behavioural alteration frequently leads to starvation and the subsequent Ketoacidosis due to starvation. —Nutricion hospitalaria 2010