Abundant in vitamins and nutrients, everyone knows that fruit is an essential staple of a healthy eating regimen. It provides an array of functional benefits to our bodies, as well as preventing a wide range of illnesses.
But is fruit unconditionally healthy, no matter how much you eat?
Several media stories in recent years have highlighted the potential risks associated with overconsumption of certain fruit-based products due to their high sugar content. And as we all know, eating too much sugar on a regular basis can cause blood sugar to rise and lead to weight gain.
Sugar isn’t the only potentially troublesome constituent in fruit. Fibre is a prominent constituent of many fruits, and while a moderate amount of it is good, overconsumption of this nutrient can make life harder for our digestive system and cause feelings of bloatedness.
So how much fruit is too much?
Really it depends on a number of factors including the type of fruit, the form in which it is being consumed, and the person eating it.
Let’s break this down into the different nutritional characteristics of fruit, and how much of each someone would have to consume for it to stop being healthy and to cause more harm than good:
Sugars: Free vs Added, and Reference Intake
Before going into the sugar content of fruit, it’s important to determine what level of sugar consumption is healthy; and when it comes to guideline amounts, sugar can be a slippery subject.
The daily reference intake of total sugar for an adult is 90 grams. Total sugar accounts for all sugars, including those consumed in main meals.
In a 51g Mars, there are 30 grams of sugar, and in a 330ml can of Coke there are 35.
Consequently, on the packaging of many products such as these, consumers will be given a reference intake as a percentage of their 90 gram total. However, sweet snacks and sugary drinks contain added sugars and the RI for these isn’t quite so straightforward.
In actuality, calories from foods containing added sugars should not exceed five percent of a person’s total calorie intake. For women this is 2,000, and for men 2,500.
So the reference intake from those foods which contain added sugars is actually much lower than 90 grams.
A 51g Mars contains 230 calories (around 10 percent of calorie RI). When you take this into account, a Mars, instead of taking up one third of your daily sugar quota, in reality takes up all of it, because it contains added sugar and takes up more than 5 percent of calorie RI.
Fruit contains what is referred to as ‘free sugars’. Although the sugar contained in whole fruits is natural and not added artificially, it falls into the same category as added sugar with regard to reference intake.
However, whole fruits generally pack more sweetness per gram of sugar than those items containing added sugar. Figs for instance, are generally considered to be one of the sweetest and sugariest fruits, and contain around 16 grams of sugar per 100g, and strawberries contain roughly 5 grams of sugar per 100g.
Fructose and Glucose
The type of sugars typically found in fruit (fructose) and sweet snacks (glucose) are processed differently in the body too.
Glucose is absorbed into the bloodstream via the digestive system, and then converted into energy by insulin, a hormone produced by the pancreas. When blood sugar levels are constantly heightened, the pancreas will struggle to generate enough insulin to keep up, and this will eventually lead to diabetes.
It is the liver which is responsible for converting fructose. So when too much fructose is consumed, this can pose liver function problems; and whatever can’t be turned into energy is stored as visceral fat around the abdomen (much like glucose).
It is therefore possible, in theory, to consume sugars from whole fruits to an unhealthy extent.
But as mentioned above, the sugar load in whole fruits is generally lower than that in sugary snacks; which means that someone would have to consume a high number of whole fruits before the sugar levels became comparative with that of those in sugar-laden sweets and snacks.
Whole Fruits vs Fruit Juices
However, the same cannot be said of fruit juices; particularly those made from concentrate. While these will be rich in vitamins and other nutrients, they will generally contain very high levels of sugar, and may even be comparable to those contained in fizzy drinks.
So while it isn’t common to exceed recommended sugar consumption when doing so from whole fruits, it is much easier to (and you might even say, likely that you will) do so when consuming fruit juices.
In one large American study of over 70,000 test subjects, whole fruit and vegetable consumption was associated with a lower risk of diabetes, while conversely, fruit juices were associated with a higher risk.
The best way to ensure that you don’t exceed your recommended daily sugar intake from fruit then, is to stick to whole fruits wherever possible.
Fruit juices can be beneficial to health, but strict moderation is the best approach; and these should not form the majority of a person’s fruit consumption.
Fibre: Can You Get Too Much?
In short, yes.
Fibre is typically abundant in fruits with skins, such as apples. It’s considered an important part of a healthy diet because it helps to lower cholesterol, and it is also digested slowly in the gut. This means that it aids a slower rate of energy release, while also providing an enduring fuller sensation in the gut; thus reducing the need for further (and potentially unhealthy) inter-meal snacking.
Despite its benefits, however, it is possible to eat too much fibre. Doing so can lead to discomfort in the gut, increased bowel frequency, wind, and a reduction in the consistency of stools. Persons with a bowel condition such as IBS may even be advised to exercise moderation when it comes to fibre during a flare-up.
The reference intake for an adult is 30 grams of fibre.
Per whole apple, there are roughly 5 grams, and in 100 grams of raspberries there are about 7 grams.
So overeating fibre from whole fruits is certainly possible.
This is why variety is so important. Different fruits and vegetables provide different levels of nutrients, so it is crucial not to just stick to one or two particularly high fibre fruits. Incorporate those which don’t have a skin into your diet too, and if you have a condition which is sensitive to fibre, try eating fruits such as apples, peaches or pears with the skin removed.
Once more, whole fruits tend to be less calorific than those sold in other forms.
- The average for a banana is about 100 calories, and for an apple is a touch less at around 90;
- whereas a serving of Medjool dates (around 4) contains roughly 250 calories, and 100 grams of raisins around 300 calories.
- a 30 gram serving of dried banana crisps contains about 150 calories.
It is much easier to exceed calorie (and sugar) RI when consuming fruits which have had their water content removed. When a person sticks mostly to whole fruits and exercises moderation when consuming dried fruits, it isn’t likely that they will overstep their daily calorie quota from fruits alone.
It must be said however, that if someone is habitually consuming too many calories, it’s probable that fruit consumption isn’t the issue. Other areas of their diet, such as non-fruit snacks, alcohol and portion sizes, are much more plausible culprits.
Eating too many calories from fruit is possible, but as long as whole fruits form the majority of a person’s intake and a varied approach is practised, it isn’t likely to occur as a result of eating fruit alone.
And Finally, Vitamins
The health benefits of vitamins are numerous, and generally well-known to us. They contribute towards better organ function, better bone and tissue strength, and better immunity.
And fruit, in its various forms, is abundant in vitamins.
Too many vitamins can however cause harm. Once more, it depends on the person, and the vitamin. But for example, too much vitamin A can over time actually lead to reduced bone strength and be a contributing factor in osteoporosis, and too much vitamin C can cause stomach cramps and digestive issues.
When it comes to overconsumption, experts say that supplements are much more commonly the problem as opposed to whole fruits; and that exceeding vitamin RI is not easy to do from food alone.
Those who are susceptible to problems caused by too much vitamin C, such as digestive issues, might try avoiding citrus fruits or acidic fruit juices, and instead opt for milder whole fruits (with the skin removed, if necessary).
To ensure you aren’t getting too much of one thing and not enough of another, the best practice is variety.
What’s the Optimum Amount?
Opinions vary, but two to three pieces of whole fruit per day is what many experts generally lean towards as the optimum level of consumption.
The general consensus is that you should be aiming for five servings of fruit and vegetables a day (not five servings of each) and, as discussed above, that a variety of items should constitute this. A serving size is 80 grams.
When it comes to fruit, diversity is just as important as quantity, to ensure you’re getting the full range of health benefits.
What’s more, fruit should not be considered an antidote to a diet which is otherwise unhealthy. If you’re concerned about consuming too many calories or too much sugar, it’s important to look at your diet as a whole, and not just how much fruit you eat.