Food & fluids

What’s the fuss about fructose?

summer fruitFor the past year sugar has been in the media spotlight.

It is now well recognised that if taken in excess, sugar (particularly sucrose) added during the processing of foods and beverages, increases the incidence of dental caries, type 2 diabetes and obesity. 1

But what about fructose, the sugar that intrinsically exists in fruits and vegetables? Could this be injurious to our health too?

In New Zealand we are encouraged, as part of the 5+ A Day promotion, to eat 3 servings of vegetables and 2 servings of fruit the size of our hand each day.

Over summer it is easy to exceed these amounts. Although root vegetables such as potato, taro, kumara, parsnip and yams do contain more starch and their intake should be controlled by the overweight, leafy green vegetables; salads; carrots and pumpkin can be eaten in any amount.

These vegetables are rich in vitamins and minerals many of which are anti-oxidants and good for our health. They are also bulky and high in fibre and soon fill us up, which in itself limits the amount we can eat.

Fruit, on the other hand, does contain the sugar fructose and over summer it’s easy to eat too much. While fruit does provide a lower fat alternative to snacks such as cheese and crackers, muesli bars, crisps, cakes and biscuits, if we are to limit fructose intake we need to keep our fruit servings to around 2-3 pieces per day and maybe learn to snack on vegetable sticks and hummus instead.

What is the problem with fructose?

It’s very plentiful

Fructose is the sugar found naturally in plants, honey, tree and vine fruit, flowers, berries and most root vegetables. Fructose can also enter our diet through table sugar, high fructose corn syrup, agave nectar, molasses, maple syrup and fruit juice. 2

It’s very sweet

Although fructose has a low glycaemic index of only 19 compared to 100 for glucose and 68 for sucrose 3, it is excessively sweet in fact 1.73 times sweeter than glucose 4.
Fructose is also more rapidly metabolised by the liver than glucose and at high levels fructose may lead to increased blood levels of triglycerides and lactate. This can be of particular concern to those who are overweight, diabetic or have elevated blood cholesterol levels.(see more in Fructose and health)

It’s easily manipulated

Commercially fructose is developed from cane sugar, sugar beets and corn. It is inexpensive and commonly added to foods and drinks to improve the taste and palatability and in the case of baked goods it improves the browning and shelf life of some food products. Fructose is also more soluble than the other sugars making it a pliable ingredient in confectionary. 5

It comes in different forms

Fructose exists as a free monosaccharide or bound to glucose as sucrose which is a disaccharide. Fructose, glucose and sucrose may all be bound within foods in varying proportions. 2

Fructose and Digestion

During digestion fructose absorption from the small intestine is aided by a protein transporter GLUT5 and also a glucose transporter GLUT2. When fructose enters the diet bound to glucose (as sucrose) in a 1:1 ratio, absorption is greater than when fructose is absorbed alone as a monosaccharide. 6.

Table 1 The balance of sugars present in 100g servings of raw fruit and vegetables


Food per 100g raw Total Total Free Free Sucrose Fructose/ Sucrose as a%ge
  Carbohydrate Sugar Fructose Glucose   Glucose ratio of Total sugar
Raisins, dried 66.8 66.8 35.2 31.6 0 1 0
Banana 20.8 15.2 5.1 5.1 5 1 33
Grapes,black 15.5 15.5 7.8 7.7 0 1 0
Pineapple 11.4 11.4 2.7 2 6.7 1 59
Pear 11.8 11.8 8.7 2.4 0.7 3 6
Apple 10.8 10.1 6.7 2.4 1 2.5 10
Apricots 9.8 9.7 4.1 3.5 2.1 1 22
Blueberries 9.3 9.2 4.9 4.2 0 1 0
Orange,naval 8.5 8.4 2.3 2.1 3.9 1 46
Kiwifruit 8.3 7.9 3.3 3.2 1.4 1 18
Peach 7.9 7.9 1.3 1.2 5.4 1 68
Strawberries 6.5 6.5 2.9 2.4 1.1 1 17
Cantaloupe melon 5.2 5.2 2.5 1.4 1.3 1.5 25
Tamarillo,red 3.8 3.5 0.9 0.8 1.7 1 48
Tomato 2.6 2.6 1.3 1.2 0 1 0
Kumara 25.7 9.6 0.5 0.7 4.8 1 50
Potato 15.4 0.3 0.05 0.15 0.1 0.5 33
Corn, Kernel 19.9 1.5 0.2 0.9 0.4 0.3 27
Yam 14.6 0.7 0.1 0.2 0.4 0.7 57
Pea, green 9.3 5.8 0.4 0.3 5.1 1 88
Carrot 6.8 6.6 1.3 1.4 3.9 1 59
Pumpkin 6.1 4.1 1.2 1.4 1.4 1 34
Onion 8.5 8 2 3.6 2.4 0.6 30
Beetroot 5.9 5.9 0 0.2 5.7 1 97
Beans, green runner 4.2 3.2 1.3 1.1 0.8 1 25
Cucumber 1.9 1.8 1 0.8 0 1 0
Lettuce 1.1 0.4 0.2 0.2 0 1


Ref Food Works® 2015 7

  • The fructose/glucose ratio is calculated by dividing the sum of free fructose plus half sucrose by the sum of free glucose plus half sucrose. The figures have then been rounded
  • Note dried fruit is a concentrated source of carbohydrate compared to most fruit and vegetables

Some foods such as apple and pear have almost twice the amount of fructose as glucose and so may be harder to absorb. This may especially affect young children, particularly when these foods are taken as juices. The immature cells lining a childs intestine have less affinity for fructose absorption than glucose and sucrose. Unabsorbed fructose creates a higher osmolarity in the small intestine which draws water into the gastrointestinal tract causing osmotic diarrhoea 8

Athletes may also be affected by fructose malabsorption as exercise can reduce the transit time of fructose traversing the gut leading to diarrhoea. 9

Incompletely digested fructose in the large intestine can become a source of nutrients for colonic bacteria increasing the production of short chain fatty acids, hydrogen, carbon dioxide and other gases causing “Irritable Bowel” like symptoms e.g. gastro-intestinal pain, bloating, flatulence and diarrhoea. As the hydrogen moves to the lungs it can be picked up by hydrogen breath testing which is proving to be a useful tool in diagnosing fructose malabsorption. 11

Where necessary a FODMAP diet can help to identify foods that trigger these “irritable bowel” like symptoms caused when short chain carbohydrates are poorly absorbed in the small intestine. (FODMAPS is an acronym derived from Fermentable Oligo-, Di-, Monosaccharides And Polyols.) 11 Fructose is the highest contributor to FODMAP intake in the US diet.
It is important to note however that these diets can be very restrictive and are not intended for longer than a 6-8 period of investigation and their use should be supervised by a Dietitian to ensure nutrient adequacy.

Once fructose has been absorbed it is transferred to the liver where it is converted into glycogen and triglycerides. This is the point at which fructose begins to impact on fat metabolism.

Fructose and health

If taken as part of a healthy diet where total carbohydrate is well controlled these sugars are not a problem. However when processed foods or concentrated sources of fructose (e.g. excess fruit or juice) are added to the diet they may not only alter absorption but can also tip the nutrient and energy balance leading to ill-health.

In excess fructose consumption leads to an increase in LDL cholesterol and raised triglyceride levels and metabolic syndrome 12; Type 2 diabetes 13; elevated uric acid levels and hypertension 14 and cardio-vascular disease 15
The over consumption of fructose can also lead to a reduction in insulin and leptin levels important for the suppression of appetite and an increase in gherlin the hormone responsible for feelings of hunger. 16 This may lead to increased energy consumption, rapid weight gain and obesity.

To sum up

  • Fruits and vegetables are a good source of vitamins and minerals particularly B group vitamins and Vitamins A, C and D. They are also an important source of carbohydrate and dietary fibre.
  • Balancing energy intake is the key to eating a healthy diet and maintaining a healthy body weight.
  • Care should be taken to not over consume fruit and fruit juices, particularly over the summer months when fruit is plentiful.
  • The 5+ A Day campaign to encourage the eating of 2 servings of fruit and at least 3 servings of vegetable the size of your hand each day is a good guide for most people.

If you would like a nutritional assessment to review your carbohydrate and total sugar intake or to assist you with managing any of the conditions mentioned in this article then contact us today

Other articles by Lea on this subject

Sugar control is essential for better health
Summer fruit warning
Nutrition for distance runners and ‘fun runs’


  1. Scientific Advisory Committee on Nutrition. Carbohydrates and Health [Internet]. London: The Stationary Office; 2015. Available from:
  3. Miller, J B.The low GI handbook 2010 ed Hachette Australia
  4. Oregon State University. “Sugar Sweetness”. Last accessed May 5, 2008. Archived May 16, 2008, at the Wayback Machine.
  5. Hanover, LM; White, JS (1993). “Manufacturing, composition, and application of fructose”. Journal of Clinical Nutrition 58: 724s–732.
  6. Fujisawa, T; Riby J; Kretchmer N (1991). “Intestinal absorption of fructose in the rat”. Gastroenterology 101 (2): 360–367.
  7. Food Works 8 2015 Composition of Australian and NZ Foods. www.
  8. Riby, JE; Fujisawa T; Kretchmer N (1993). “Fructose absorption”. American Journal of Clinical Nutrition 58 (5 Suppl): 748S–753S.
  9. Fujisawa, T, T; Mulligan K; Wada L; Schumacher L; Riby J; Kretchmer N (1993). “The effect of exercise on fructose absorption”. J. Clin. Nutr. 58 (1): 75–9.
  10. Skoog, SM; Bharucha AE (2004). “Dietary fructose and gastrointestinal symptoms: a review”. J. Gastroenterol. 99 (10): 2046-50
  11. Shepherd SJ, Parker FJ, Muir JG and Gibson, PR Dietary triggers of abdominal symptoms in patients with irritable bowel _syndrome- randomised placebo-controlled evidence Clin. Gastroenterol. Hepatol. 2008;6(7):765-771
  12. Basciano H, Federico L, Adeli K (2005). “Fructose, insulin resistance, and metabolic dyslipidemia”. Nutrition & Metabolism 2 (5): 5.
  13. Malik, Vasanti S.; Popkin, Barry M.; Bray, George A.; Després, Jean-Pierre; Willett, Walter C.; Hu, Frank B. (2010-11-01). “Sugar-sweetened beverages and risk of metabolic syndrome and type 2 diabetes: a meta-analysis”. Diabetes Care 33 (11): 2477
  14. Perlstein, Todd S.; Gumieniak, Olga; Williams, Gordon H.; Sparrow, David; Vokonas, Pantel S.; Gaziano, Michael; Weiss, Scott T.; Litonjua, Augusto A. (2006-12-01). “Uric acid and the development of hypertension: the normative aging study”. Hypertension 48 (6): 1031–1036.
  15. Rippe, James M.; Angelopoulos, Theodore J. (2015-07-01). “Fructose-containing sugars and cardiovascular disease”. Advances in Nutrition (Bethesda, Md.) 6 (4): 430–439.
  16. Teff, KL; Elliott SS; Tschöp M; Kieffer TJ; Rader D; Heiman M; Townsend RR; Keim NL; D’Alessio D; Havel PJ (June 2004). “Dietary fructose reduces circulating insulin and leptin, attenuates postprandial suppression of ghrelin, and increases triglycerides in women”. J Clin Endocrinol Metab. 89 (6): 2963–72.

About the author View all

Lea Stening

Lea is one of New Zealand’s leading paediatric dietitians and also specialises in Sports Nutrition. She has specialised in Paediatric Nutrition for 31 years and in 1985 was the first paediatric dietitian to enter private practice in New Zealand. Lea helps families through her private consultations, public lectures, newspaper and magazine articles as well as television and radio interviews. Read more »

View all posts by Lea Stening »


Leave a Reply

Also in Food & Fluids View all »

  • Food, beverage and fitness trends for 2023

    Globally there is disruption to supply chains, inflation, changes in technology and war in many regions. Food systems are experiencing instability which is changing the trends in our choice of food, beverages and fitness. Read more »

  • Are you blending rather than chewing your food?

    With families on the go every day it’s often easier to down a smoothie for breakfast than to sit down and eat. While this is certainly better than not eating at all we really do need to take the time to chew our food. Find out why?.. Read more »

  • 5 good reasons to eat breakfast

    Thinking of skipping breakfast? If you think you'll be saving time, money and calories then think again. Research finds you are more likely to miss vital nutrients peculiar to breakfast foods and to snack on more calories later on. Read more »

  • Milk is a valuable sports nutrition supplement

    Whether you are an athlete wanting to improve your performance or just keen to improve your level of fitness, interest is growing in the use of milk as a sports supplement that is good for your health at any age. Read more »

  • Are you an emotional eater?

    Emotional eating isn't an eating disorder. It is a dyfunctional relationship with food. Associated with depression, anxiety and binge eating. It is highly addictive, causes ill health, needs to be taken seriously. Here are tips to help. Read more »

  • Thinking of going vegan?

    Veganism can be a very healthy lifestyle but there are some important things to know about before deciding that veganism is going to be right for you and will provide sufficient energy to fulfil the life goals you have in mind Read more »

  • Tips to reduce ‘added sugar’ intake for...

    Are you keen to get healthier this Christmas and 2022? Then start by cutting back on 'added sugar'. Without giving up all carbohydrate there are lots of ways you can control your blood sugar levels. Here's some tips to help. Read more »

  • Dietary Guidelines are constantly changing:...

    Although science is constantly evolving, generating new recommendations to improve our health, for many people their eating habits are based on things other than their longevity so are guidelines still relevant today? Read more »

  • 5 good reasons for eating eggs

    Are eggs really cheap and nutritious when compared with other protein rich foods? What about cholesterol? and are they safe to eat raw or if you're pregnant? Find out .. Read more »

  • Coffee concoctions

    Whether we sit in or take out it seems our love affair with coffee just keeps growing. Let's take a quick look at the effect our choice of coffee may have on our nutrient intake. Read more »

  • Potatoes – they’re maybe healthier...

    Potatoes are often labelled too starchy, too fattening too boring, but is this fair? As we grapple with Covid-19 maybe it's time to take a fresh look at how eating potatoes nationally could help our health and economic growth Read more »

  • Snacking on the plant-based diet

    Business is booming in the snack food trade. However not all commercially available foods are good for our health. Find out how planning snacks can help to power your day Read more »

  • Can caffeine improve your performance?

    New Zealand ranks 13th in the world for coffee consumption ahead of Australia and USA. What are the effects of caffeine on our health and can it improve our performance? Read more »

  • Soup to soothe

    There is something very comforting about a bowl of soup especially on a cold winters day or if you are feeling unwell. Here we compare soups available today and offer guidelines on choosing the healthiest. Read more »

  • The active life of yoghurt

    Yoghurt is a healthy, economic and beneficial way to supply the body with macronutrients particularly protein and calcium, very convenient as a meal or snack its health benefits could help you. Find out more.. Read more »

  • Alcohol and sport- Is it a good match for you?

    When used responsibly alcohol can help to relieve tensions in athletes and to build feelings of inclusiveness in a team. However in excess it can slowly unravel training, health and sporting careers. Read more »

  • Don’t like fish?

    Fish is high in protein, iron, B group vitamins and essential fatty acids. But not everyone likes it. What can parents do to help their child try it again? Read more »

  • Are nuts all they are cracked up to be?

    Are nuts healthy and how much do we need to eat in order to enjoy their health benefits? Read more »

  • Wise up to Discretionary Foods for better health

    If you are struggling to lose weight or lower your cholesterol then taking a closer look at your intake of discretionary foods can improve your results. Read more »

  • Could you make healthier decisions when shopping?

    Every food item we drop into our supermarket trolley isn’t just affecting us but also the health of those we provide food for. How well do you shop? Read more »

  • How to put ‘real’ flavour into...

    It can be so easy to snip the top off a packet of flavouring when cooking. But if we really want to reduce the salt, fat and sugar in our diet natural flavours are best. Find out how. Read more »

  • Get children cooking this Christmas

    Increasing the confidence of children to cook from scratch is now seen as part of the strategy to reduce chronic diet related disease and obesity. We offer 12 top foods to know how to cook before leaving home. Read more »

  • Garnishes galore and all those “little...

    Is garnishing getting out of hand? Find out how much energy those "add ons" really do add. Read more »

  • 8 tips to help you break the sugar habit

    What habits would you like to break? With all eyes on sugar reduction learn the steps to make this happen to achieve better health now. Read more »

  • Time your eating for better performance?

    If playing sport or exercising, understanding the GI can help you to select foods that will provide optimal energy at key stages of activity for better performance. Read more »

  • Get into fruit and vegetables for optimal health

    Do you get your 5+ A Day servings of fruit and vegetables? Learn how gardening and creative activities can improve your consumption of these foods and maximise their nutritional benefits for better health. Read more »

  • 15 Tips for healthier barbeques this Christmas

    Are you planning a Barbeque this Christmas? It's not hard to lower everyone's saturated fat, salt and sugar intake while still serving beautiful, tasty food. Read more »

  • Tips to help you ‘shake off’ the...

    In a bid to reduce the intake of processed foods many food manufacturers are modifying their products to meet new food guidelines particularly regarding salt. Find out if you are still getting too much? Read more »

  • What’s to drink?

    As concern, regarding the sugar and energy content of carbonated drinks and fruit juice, gathers momentum many people are looking for alternative drinks to have. Read more »

  • Is going “Gluten Free” a healthy...

    As the popularity of gluten- free diets grow we need to question whether in fact it is a healthy option for any of us and if not how can we make it so? Read more »

  • 8 Healthy tips when making ‘real food’...

    If we choose a lifestyle where others grow and process our food can we be sure that it is still safe to eat? Find out more. Read more »

  • Does your diet tick all the boxes?

    Is dieting still fun if it ages you? Find out if your diet ticks all the boxes for your better health and performance. Read more »

  • Organic food markets are gaining traction

    Organic foods are more expensive but as more farms convert to organic food production the costs do come down and the savings to the environment by reducing pollution and conserving water and soil quality may, in the long-term, be money well spent Read more »

  • Fish and mercury contamination

    While fish can also contain some mercury it is still possible to enjoy the health benefits of eating fish and keep the exposure to mercury within safe limits. Read more »

  • Juice diets – are they as healthy as...

    For busy people, who might rather drink than chew their fruits and vegetables, the juicing trend sounds like a "gods send". What possible disadvantages could there be to health? Find out the pros and cons of this new diet craze. Read more »

  • Taste is important to fluid consumption

    Taste is an important factor affecting fluid choice and level of consumption and therefore is an important consideration to overall sporting performance Read more »

  • Feeling full is the secret to weight loss

    Gaining an understanding of the many factors contributing to a sense of fullness can provide some very powerful tools for those seeking to lose or control body weight and find more energy for life! Read more »

  • Milk matters

    How safe is cow’s milk in the raw and homogenised state? When can cow’s milk be given to infants and how can we protect children against developing allergies to cow’s milk? These are just some of the questions that have come up in the media lately and are in need of some clarification Read more »

  • Muesli and sports bars can aid performance

    Muesli and sports bars are designed to provide a convenient source of energy to be thrown into a lunchbox, gym bag or pocket and eaten “on the run”. However if eaten daily as a “lolly” or relied on as a meal replacement they can lead to unnecessary weight gain. If used wisely during training and competition they can provide athletes with a measured source of carbohydrate vital to performance. Read more »

  • Healthy meals for one

    Coming home to a nutritious cooked family meal was once the norm for many of us. Recent social change however is now seeing more people living in single dwellings many of whom are turning to meals “on the run” that are quick and easy to prepare Read more »

  • Can coconut improve our health?

    Coconut oil was once associated with tanning. Something young people coated themselves with before lying out in the sun “to bake”. Today coconut products are being heralded by many as the new “wonder food" that can cure many ailments. We take a look at some of these claims. Read more »

  • Food planning is important for hiking safety

    Research does show more injuries occur in the mid-late afternoon in open country than other times of day. This is often when people become dehydrated, their muscle levels of energy (glycogen) can become depleted and blood glucose levels may be falling, all factors which lead to fatigue Read more »

  • Sugar control is essential for better health

    After years of encouraging a low fat diet with some success (a decline in heart disease and some forms of cancer) attention is now focusing on sugar as a possible reason for our weight and diabetic problems. Read more »

  • Boosting fibre intake offers health benefits

    Research shows that a diet high in fibre can reduce the risk of developing diseases such as type 2 diabetes, coronary heart disease, bowel and breast cancer, gallstones, diverticular disease and weight gain. It also seems that some fibres are better than others. Read more »

  • How to increase the ‘Good’ fats...

    If you are thinking of cutting fat out of your diet stop right now. Fat is important for nerve and cellular function but choosing the right “type” of fat is what matters most to our long term health. Read more »

  • Can a high fat diet improve sports performance?

    Fat carries more energy than other macro nutrients (9kcals/37kJ/g compared to 7kcal/29kJ/g for alcohol and 4kcal/17kJ/g for protein and carbohydrate respectively). So with so much energy to offer does eating more improve performance? Read more »

  • How much food do you waste every day?

    In New Zealand around 258,886 tons of food waste is dumped in landfill each year. This equates to around 64kg of food waste per person/year in NZ compared to 82kg /person/ year in the USA. Read more »

  • Healthy ideas for family takeaway meals

    Did you know that in 2012 around 21% of New Zealander’s weekly food expenditure was spent on eating out and takeaways? Read more »

  • Are you a “sneaky snacker”?

    Some people find it hard to control snacking and are continuously thinking about food. They may find themselves constantly picking, stock piling foods in drawers and cupboards at home and work. Read more »

  • Give healthier gifts this Christmas

    If you want to enjoy the company of friends and family when you get older then if is important that you look after their health, as well as your own, as you age. Read more »

  • “Free foods” for hungry children

    Free foods", while bulky, are very low in energy and filling. So their cost in terms of calories is much lower than most other dietary components, hence the term "free". As these foods are also naturally fat free they make ideal snacks for anyone trying to control body weight Read more »

  • Party plans for children

    Birthday parties should be fun and the chance to celebrate a child’s special day with a minimum of work and cost for busy parents. If the party can be timed to fit around a normal meal time then “junk” foods can be kept to a minimum. Read more »

  • Care for “the carers” during family...

    When family members are sick or hospitalised it can be very challenging to find the time to exercise and maintain a healthy diet for yourself. Particularly if you are working, caring for children, or trying to complete a course of study. Read more »

  • What are our children drinking?

    In 2015 New Zealanders consumed a total of 518 million liters of carbonated drinks. Outside of the drinking of milk and water there is real concern about the energy content of some of these beverages because of our rising incidence of diabetes and obesity. Read more »

  • Drink milk for better health

    Fonterra’s announcement that it will sponsor free milk in schools is good news for the future health of young New Zealanders. Milk is promoted on the basis of bone health but there are many other health benefits that should be promoted. Read more »

  • Make healthy decisions this Christmas!

    We all like to think that we call the shots regarding what we eat and drink. But who really has the last say over what we swallow? Read more »

  • Marvellous mushrooms

    Did you know? New Zealanders consume 2.7kg of mushrooms per person each year. Mushrooms rank as the third most popular vegetable in this country in 2010. White button mushrooms are the most commonly eaten type of mushroom in New Zealand. Mushrooms do not need light to grow. They obtain all their goodness and nutrients from … Read more »

  • Brace yourself for the brassicas

    With Winter now upon us its time to eat more Brassica vegetables. What are they? Broccoli – 7th most popular vegetable in New Zealand Cauliflower – 13th most popular Cabbage (all types) – 12th most popular Brussel Sprouts Broccolini – consumption rocketing! Swedes Turnips Why are they so good? Brassicas contain: Antioxidants, from the following … Read more »

  • Navigating Christmas without weight gain

    Measurement is an important evaluation tool at any time of the year, it is only human nature to want some means of measuring progress; however can we rely solely upon any particular measure and expect to obtain a reliable result? For each aspect of life we require some measure to determine our successes or failures, … Read more »

  • Alcohol and type 2 diabetes

    The protective role of alcohol in protecting against heart disease has been reported throughout various media sources in previous years, however only recently has it also been shown in people with Type 2 Diabetes. Epidemiological evidence suggests that a light to moderate alcohol intake may have a protective role against the development of Diabetes in … Read more »

Would you like to subscribe to our fantastic FREE monthly newsletter?

Each month we'll keep you up-to-date with the latest nutritional articles and healthy recipes from You are free to opt out at any time, but we think you'll enjoy what we've got in-store for you.

Plus as a bonus offer — subscribe today and receive FREE weight loss tips for two weeks! Learn how a number of foods, many one would consider 'healthy', may in fact be slowing your progress.


Yes please, it sounds great! (and it's FREE after all).



No thanks, I'm not interested (or I'm already a subscriber and really enjoying these fantastic newsletters!).