Fruit comes in many varieties from tiny berries to huge water melons they are available all year round due to importation and modern growing techniques. It is easy to carry with you so can be a convenient snack when on the go and keeps the kids happy while going around the shops, but is it as good for you as we think and should we be eating so much?
Before we start I am not saying let's get rid of fruit totally from your diet however there are some things to think about before over doing it.
The dietary foundation of this lifestyle is that we are trying to eat as closely to what our ancestors would have eaten, foods that they would have been able to find on the landscape either by hunting or gathering. So fruit is something that would have clearly been on the menu.
One major difference however is that they would not have had access all year round, fruit would have been a small window of opportunity when they were in season, once that season had passed they would have to wait until the following year before eating it again. Also the fruit they would have eaten would have been smaller and more sour in comparison to our modern hybrids. Over time we have cultivated and cross bred varieties to be sweeter, larger and high yielding.
Here is one of the problems with fruit, as usual it's the sugar! If you have read any of my previous posts you will have noticed sugar a few times so I will briefly recap. We use sugar in the bloodstream for energy production in the form of glucose and we store it as glycogen in the liver. When sugar is present the pancreas secretes insulin to signal cells to use it for fuel and also signal the excess to be stored as fat. So from a weight control and loss point of view we can see that fruit or at least to much fruit can be a bit of a problem.
The constant use of carbohydrate (sugar) can be a road to insulin resistance, when the cells no longer accept the signals from insulin, this is a precursor to type 2 diabetes and a buildup of excess glucose in the blood and remember excess gets stored as fat. This is why diabetes is highly correlated with obesity.
But its natural sugar?
This is a fair point to make, sugar from fruit is natural but it is important to remember that sugar is sugar it doesn't matter if it is from table sugar or a banana. In fact the primary sugar in fruit is fructose which has the potential to be more problematic as it has to be metabolised in the liver meaning a stronger chance of it being converted to fat for storage and there are studies that show higher fructose consumption can raise lipid profiles in the blood, higher triglycerides, higher LDL and lower HDL.
With all this in mind there are certainly better options to choose, it make sense that choosing lower sugar fruit would be a better choice but which are best. You can usually judge it on taste if it's sweet it has more sugar and less if sour however this is a little unscientific. A better way is to look at a fruits glycemic index (GI) and glycemic load (GL). GI is a measurement of how fast food has an effect on blood sugars based on a 0 - 100 scale. 100 is pure glucose so the closer to 100 the faster the blood sugar spike. GL is telling us carbohydrate you are getting per serving.
Here is a list from best to worse choice based on GI but I have put the GL in for reference. Serving size should also be considered, so just because cherries have the lowest GI don't just eat an entire punnet.
Raw cherries - 117g GI 22 - GL 3.7
Plum - 1x GI 24 - GL 1.7
Grapefruit - Half fruit GI 25 - GL 2.8
Peach- 1x GI 28 - GL 2.2
Prunes - 132g GI 29 - GL 34.2
Pear - 1x medium GI 38 - GL 6.9
Apple - 1x medium GI 39 - GL 6.2
Strawberries - 152g GI 40 - GL3.6
Grapes - 92g GI 43 - GL 6.5
Orange - 1x GI 48 - GL 7.2
Blueberries - 150g GI 50 - GL 0.9
Mango - 165g GI 51 - GL 12.8
Banana- 1x medium GI 51 - GL 12.2
Kiwi 1x GI 58 - GL 5.2
Fig 125g GI 61 - GL 11.7
Raisins Small box GI 64 - GL 20.5
Pineapple 155g GI 66 - GL 7.2
This is not a comprehensive list but it should give you a place to start while making choices, fruit does have lots of good nutritional value but the sugar can be a problem if overdoing it. This all said I would rather you reached for a banana in a time of need that the chocolate bar (Unless its 70%+ dark)