Are Fruitarian Diets (80/10/10 or 90/5/5) Really Healthy?

“I am interested in following a fruitarian diet to detox and lose weight. Is eating nothing but fruit really healthy?” – Peter

I’m glad you asked this question because I’ve wanted to address this topic for some time. I have a lot to say about fruitarian diets.

A fruitarian diet consists of primarily fruit, usually sweet fruit such as bananas. Some people consider themselves a fruitarian when they consume more than 75% of their diet from fruit. Typically, a fruitarian will eat up to 95% of their daily caloric intake from fruit.

Some fruitarians consider nuts and seeds “fruit” while others do not. In fact, most fruitarians promote a very low fat, raw food vegan diet. Avocados, coconuts, durian and other fatty fruits, as well as nuts and seeds, make up a minor role in the diet and are generally avoided by those on a strict diet.

Fruitarianism vs. The 80/10/10 Diet

The 80/10/10 diet promoted by Dr. Douglas Graham is considered a fruitarian diet, although the macro-nutrient ratio could apply to a mostly raw diet that includes cooked whole food carbohydrates.

Many fruitarians take the diet further and strive for a dietary ratio of 90/5/5 (90% of calories from carbohydrates (mainly sweet fruit), 5% or less from protein, 5% or less from fat). Some fruitarians avoid eating any overt fats in the diet, only getting small amounts that are naturally found in low fat plant foods such as fruit.

In the context of a strict, raw food vegan diet, I find that Dr. Graham’s 80/10/10 protocol is generally adequate for providing sufficient amounts of most nutrients IF the diet is sufficient in calories. However, I caution against following any dietary protocol too rigidly.

While Dr. Graham seems to be against proactive supplementation of vitamin B12, or eating sea vegetables (for iodine), and considers all cooked food to be toxic, I disagree and find balance and peace of mind with taking B12, eating sea vegetables for iodine and balancing my diet with healthy, cooked whole foods like beans, rice and quinoa.

Furthermore, I consider 80/10/10 to be a good starting place for those interested in a raw food diet. It’s what I recommend that people start with if they are interested in going raw vegan or while they are losing weight. However, some people might find that they do better when they get more than just 10% of their calories from fat. Some might do best with 15% fat while others might do best with 30% fat. So it’s important to pay attention to your body and don’t force yourself into a committed relationship with a macro-nutrient ratio.

A 100% raw, fruit-based diet might be hard to stick to long term for some people when the fat intake exceeds 20%, so a high-raw diet that includes cooked beans, rice and quinoa would still be healthy for those who need up to 30% of their calories from fat, or for whatever reason can’t consume all or most of their carbohydrates from sweet fruit.

I’ve been following the 80/10/10 macro-nutrient ratio for almost three years now [February 2013] and I am quite comfortable getting anywhere from 70-80% of my calories from carbohydrates, and a significant amount of those carbohydrates come from sweet fruit. However, I don’t consider myself a fruitarian. I don’t shun non-fruit carbohydrates. I am not a strict raw foodist. I don’t always rigidly adhere to a tightly restricted fat intake at each meal. I don’t have an ideological bias toward fruitarianism.

Nutrient Deficiency Risks On Strict Fruitarian Diets

I find that when the dietary ratio is skewed past 80/10/10, nutrient imbalances show up. For example, 90/5/5 may result in inadequate protein (more on this below), calcium, iron (especially in women), zinc, selenium and iodine. These nutrients could also be low in an 80/10/10 diet or any diet if you’re not paying attention to what you are giving your body for nourishment.

Both methionine and lysine, two essential amino acids that can be a challenge to meet adequate intake guidelines on vegan diets already, may be impossible to get enough of when fat and protein intake are dropped too low and calories are not dramatically increased. Essential fatty acids may fall below established adequate intake guidelines, and DHA/EPA omega-3s may be non-existent in the diet since supplementation is often frowned upon (so no algae oils).

To resolve this problem, many fruitarians dramatically increase calories in order to increase their nutrient intake. Of course, it’s virtually impossible for your average office worker to consume 3000+ calories per day of fruits and vegetables. Many fruitarians don’t blink an eye about eating 8-12 bananas in a single meal, or 30 bananas in a day.

Most successful fruitarians are athletes, usually distance or endurance runners or bicyclists where a legitimate demand for high-calories and a massive amount of carbohydrates fuel rigorous physical activity. However, it is unrealistic to suggest that a very high-calorie, strict fruitarian diet is feasible for everybody who does not or cannot be an athlete, and therefore eat like one.

The other way that some fruitarians resolve the insufficient nutrient intake problem is by promoting skepticism about the established nutrient intake guidelines set by government and scientific organizations. I’ve heard some people claim that low fat raw vegans don’t need 1000 milligrams of calcium per day (the scientifically established recommendation), and that they are just fine consuming only 500 milligrams per day.

Others cut established, scientific dietary intake guidelines on some minerals or essential amino acids in half so that they fit within their own nutritional analysis of their ultra-fruitarian diet. They either cite some alleged “conspiracy” about why the nutrient guidelines are so high (IE: “only SAD or cooked food eaters need that much of this or that nutrient”), or they simply use their own unscientific reasoning (IE: “women in Africa don’t get as much calcium as westerners and they don’t get osteoporosis, therefore it is safe for me to cut my calcium intake in half”).

The problem with this train of fruitarian “logic” is that instead of adapting the diet to fit established scientific facts and guidelines based on experimental observations established by a majority of scientists within a rigorous, peer-reviewed process, they are adapting the facts to fit their fruitarian diet ideology. If you ask me, that’s a recipe for a health disaster!

More Pitfalls of Strict Fruitarianism

Besides the nutrient imbalances that may manifest when macro-nutrient ratios tip beyond 80/10/10, there are other pitfalls of a strict fruitarian diet.

One common side effect of a fruitarian diet is dental problems, which are generally caused by poor dental hygiene and/or insufficient minerals in the diet due to the avoidance of dark, leafy greens like kale and dandelion. Some fruitarians avoid overly bitter greens because they believe that the bitter taste is a signal that they are somehow harmful or not optimal for the human body.

Many fruitarians prefer mild-flavored lettuces to very bitter greens like kale. However, my research and personal experience consistently shows that minerals fall below established dietary guidelines on a raw vegan diet when leafy greens such as kale and dandelion are avoided or minimized, or when greens are consumed in amounts smaller than two bunches per day (about 6-8 cups), every day, especially when the total daily calories are below 3000.

I generally follow the 80/10/10 macro-nutrient ratio and have not had dental problems despite the amounts of green smoothies and sweet fruits I eat. My most recent dental checkup (January 2013) revealed a perfect bill of health. I attribute that to my mineral rich diet of dark, leafy (bitter) greens in green smoothies and proper dental hygiene.

Fruitarianism and Libido

Other side effects of a strict fruitarian diet include decreased libido, which is often promoted as a “spiritual benefit”. I’ve read, while shaking my head in disbelief, quite a few blog posts from fruitarians who claim that a tanking libido is a good thing. I probably don’t have to tell you that it is absolute NOT a good thing!

A tanking libido after being on a strict fruitarian diet for a while, especially in men, could signal insufficient testosterone production due to a variety of factors that can be exacerbated by a fruitarian diet that is too low in fat, deficient in zinc, selenium, vitamin D and too high in fiber.

Low libido is also a symptom of hypothyroidism, possibly exacerbated by an iodine deficiency from long term avoidance of iodine-rich foods such as sea vegetables. [Interestingly, hypersensitivity to cold is also a symptom of hypothyroidism. A lot of ultra-low fat fruitarians complain of cold intolerance.

Symptoms such as low libido, mood changes, decreased energy, changes in menstruation, diminished athletic performance, or any of the other symptoms of low testosterone or hypothyroidism should be checked out by a qualified health care professional. Blood tests for testosterone (total and free) as well as a thyroid panel may confirm a hormone issue, or rule it out.

Fruitarian Diets and Protein

While it is true that fruit contains protein, including all essential amino acids, fruitarian diets are notoriously low in protein. The longer I research health and nutrition, and the longer I eat a mostly raw, vegan diet, the more I have come to appreciate the importance of protein (from plant sources).

A lot of vegans, especially raw vegans, make the mistake of minimizing the importance of protein to the effect that they poo-poo even the slightest concern about it. While it is true that you can get adequate protein (total grams) on a raw vegan diet, you should never let your protein intake fall below established dietary guidelines.

In general, obtaining 10% of your calories from protein as part of a calorie-sufficient 80/10/10 diet provides adequate protein for an average, sedentary or moderately active person. Someone can meet their minimum protein intake on a 2000 calorie-per-day 80/10/10 vegan diet that is 100% raw. Dropping protein intake below 10%, however, may put you at risk for under-consuming protein. Some people might need to consume more than 10% of their daily calories from protein.

While you are extremely unlikely to experience kwashiorkor (a protein deficiency disease that is rare in developed countries) from inadequate protein intake, I’m not convinced that long-term, low grade protein insufficiency is something that should be dismissed, or taken lightly.

While protein over-consumption is a health concern in western diets, let’s not completely overlook protein. It is still an essential nutrient. Not only should you be sure you are hitting adequate intake guidelines set by scientific organizations (not protein supplement websites), you should also make sure you are getting adequate amounts of all essential amino acids including methionine and lysine, two amino acids that play hard to get on vegan diets, let alone highly restricted, ultra-low protein fruitarian regimens (when protein is less than 10% of total calories).

Who Is Fruitarianism Best Suited For

Fruitarianism, or very high-carbohydrate diets, is best suited for endurance athletes. Runners, cyclists, even swimmers, may benefit from a very high-calorie, fruitarian diet that meets all nutrient intake recommendations set by established scientific organizations. This diet promotes a lean, slender body with very little body fat. It is easy to become underweight on this diet, so extra care needs to be taken to boost calorie intake and not be too restrictive on the diet.

Fruitarianism is challenging for those who are sedentary. While I have found that 80/10/10 works quite well for me (I spend a lot of time working on a computer), anything over 80% of calories from carbohydrates can be a problem for some people. Sometimes I find it necessary to tweak my macro-nutrient ratios, sometimes doing 70/15/15 or other ratio.

A strict, calorie-sufficient, 100% raw fruitarian diet that meets 100% of established intake guidelines for ALL essential nutrients might be impossible for a typical office worker to follow when it comes to caloric intake requirements and the massive volume of food needed to obtain sufficient nutrients.

For those who want to “bulk up”, add muscle or put on healthy weight, fruitarianism (and strict, raw vegan 80/10/10) is a real challenge. I don’t know of any bodybuilders who eat a fruitarian diet, or 80/10/10 for that matter.

Strict fruitarian diets are never appropriate for children and pregnant/nursing women.

Should I Give A Fruitarian Diet a Try?

Before jumping into fruitarianism, ask yourself why you want to make the change in diet.

If you are trying to lose weight, you don’t need to become a fruitarian to do it. Sure, you could lose a lot of weight while eating massive quantities of sweet fruit, but are you prepared to make the lifestyle change? Are you willing to regularly train in a physical sport at an athletic level? Are you willing to eat 3000 or more calories per day from sweet fruit? Can you picture yourself chomping down on a 12-banana meal? Perhaps a mostly raw, low fat vegan diet would be more appropriate than a rigid and strict fruitarian one that eliminates all overt fats.

Looking at a fruitarian diet as a short-term strategy to lose weight is a terrible idea. Once you end the diet, the weight will come right back on.

If you are trying to detox, a fruitarian diet is seemingly ideal, but only for a very short period of time. I don’t recommend undergoing any dietary detox regimen for more than 4-7 consecutive days, and no more often than four times in a year. You don’t need to embrace strict fruitarianism in order to facilitate detox.

In short, I find that a macro-nutrient ratio between 65-80% carbohydrates (with lots of fruit), 10-15% protein and 10-20% fat tend to work for most people on a calorie-sufficient, mostly raw food, plant-based diet. This is generally a nutrient-sufficient diet (provided sufficient intake of calories).

Skewing these ratios too far in either direction tends to cause problems. Because of this, I don’t recommend any diet protocol that reduces fat intake below 10%, nor do I recommend any strict, rigid diet that defines itself primarily by one group of food based more on ideology rather than science and modern human physiology.

My recommendation is to give the 80/10/10 diet a try, but feel free to tweak the macro-nutrient ratios after doing it for 30 days. Resist taking it to the extreme and use a nutrient tracking software (like Cron-o-Meter) to ensure that you are meeting scientifically established nutrient intake guidelines. If any nutrients are missing or inadequate, tweak your diet by modifying the macro-nutrient ratios and add “non-fruitarian” foods.

Ultimately, you should take some blood tests to ensure that your diet is working for you. In a perfect world, you’d do a “baseline” blood test before you start a low fat or 80/10/10-type diet. After about eight weeks or so, retest and see what your numbers are doing.

For men, I highly recommend doing a baseline testosterone (total and free) before and after a dramatic diet protocol. For both men and women, it’s important to make sure that your body is getting the nutrients it needs from your diet, but also, it is critically important to ensure you’re giving your body what it needs to produce sufficient hormones.

The big take-away here is that there’s something to be learned and gained from any diet experiment. But don’t let any diet define you, and don’t define yourself by any diet.

Read more articles about the raw food diet.

Tracy Russell is the creator of RESET 28: A 28-Day Program For Energy, Weight Loss & A Healthy Glow, and founder of Incredible Smoothies. She has been helping people take control of their health and well being with green smoothies, a whole foods diet, and fitness since 2009.