Dave Mercer Liverpool Personal Trainer

Does fruit make you fat?

Don’t eat this, make sure you eat this, this makes you lean, sugar makes you fat, fat makes you fat, this gives you cancer blah blah blah, when will all the confusion and mixed messages stop?! Today while I was tucking into my bowl of oats and fruit, I was thinking about how easy and affordable frozen fruit is especially when compared to fresh fruit. A 2.5kg bag of frozen blueberries  is about £7 from Costco, while 500g of fresh blueberries from Marks and Spencer can set you back £5 (and let’s be honest, how fresh are they really?). So it lasts longer and is better value, but is frozen fruit better for you? Stick around and I’ll tell you all you need to know about fruit!

The Fruit and fructose confusion

  • Fiction: “Fruit sugar is the same as table sugar”                                                                     
  • Fact: Fruit is made up of monosaccharides (single chain or simple sugars which include glucose, fructose and galactose) and a disaccharide. It is a combination of fructose and glucose and sucrose (a bonded version of glucose and fructose) in different ratios. Table sugar is similar and is a disaccharide called sucrose. Sucrose is a combination of glucose and fructose and is a straight 50/50 split of the two monosaccharides.
  • Fiction: Fruit is just fructose and fructose is bad for you as it’s found in corn syrup”.            
  • Fact: Fructose forms only 50% of corn syrup. Fruit is made up of both fructose and glucose, fibre and lots of different vitamins and minerals (also known as micro nutrients). Some fruits have a similar fructose ratio as table sugar but it does not contain the good stuff fruit has in it. Different fruits have varying levels of fructose, normally between 40 to 55% of fructose, however apples and pears are up to 65% and cranberries are as low as 20%.
  • Fiction: Fruit sugar is only used as liver glycogen”.                                                                 
  • Fact: As fruit is a mixture of glucose and fructose, some of the glucose is used in the liver (about 20% of it) and the rest is taken off in to the bloodstream to be used as energy. Fructose is metabolised straight away in the liver as the liver wants to get rid of it, and it can be converted in liver glycogen after a number of processes. There are minimal amounts of fructose in fruit and according to Kamen Patel of examine.com the body can handle about 15-50g of fructose a day without any negative damage (if you are in a energy balance).
  • Fiction: “When I eat fruit my stomach bloats”                                                                           
  • Fact:  This can be true and is down to a number of factors, like the amount of fruit consumed, type of fruit (if you have some sort of allergy to it) or the amount of fibre in it.  As mentioned before, certain fruits have higher concentrations of fructose, and large amounts can actually cause problems because gut bacteria will feed on excessive fructose.

Scientific evidence

In a paper published in the academic journal, Nutrition Reviews, which looked at the relationship between fruit and vegetable consumption and body weight in epidemiologic studies, the authors concluded “Given the recent surge in obesity, effective dietary strategies for weight management are required. Because fruits and vegetables are high in water and fibre, incorporating them in the diet can reduce energy density, promote satiety, and decrease energy intake.”

Bottom line

So should you be eating fruit if you are trying to lose weight? Well, it depends on a number of factors: are you active? do you enjoy a few pieces of fruit a day? do you consume a very limited intake of sodas and processed sweetened foods? If the answer to all the questions is yes, then some fruit in your diet will have a very positive effect and can be part of a healthy balanced diet. Fruit as a whole is full of nutrients, high in fibre vitamins, minerals, and low in fat and calories. But don’t fool yourself in thinking that loads of fruit and being ‘healthy’ will sort your weight loss problems but replacing that chocolate desert for some greek yoghurt and fresh berries will.

Here is one of my favourite recipes using frozen fruit – enjoy!

Recipe: Frozen fruit high protein ice cream

150g frozen berries

170g total greek yogurt

1 scoop of whey protein

1. Add yoghurt and protein to blender

2. Then add frozen fruit

3. Pulse for 5 secs rest for 5 seconds repeat 3 times

4. Eat immediately


Kcals 330 for 2 portions


What Epidemiologic Studies Tell Us about the Relationship between Fruit and Vegetable Consumption and Body Weight Restricted access

Beth Carlton Tohill, Jennifer Seymour, Mary Serdula, Laura Kettel-Khan, Barbara J. Rolls

Nutr Rev (2004) 62 (10): 365-374 DOI: http://dx.doi.org/10.1111/j.1753-4887.2004.tb00007.x First published online: 1 October 2004